SpaceX Launch Not So Perfect After All

First time accepted submitter drichan writes "Those of us who watched the live feed of last night's Falcon 9 launch could be forgiven for assuming that everything went according to plan. All the reports that came through over the audio were heavy on the word "nominal," and the craft successfully entered an orbit that has it on schedule to dock with the International Space Station on Wednesday. But over night, SpaceX released a slow-motion video of what they're calling an 'anomaly.'"

Comments

An

[JustOK]

An anomaly? That's strange.

Re:An

[Anonymous Coward]

It may work. It may won't. Too early to say, though.

What I don't like is the fact that space is becoming increasingly privatised.

At first the government did the work, and quickly.

Then it contracted out some work to a few agile aerospace businesses, and things worked OK for a short while. (*)

Then contract costs shot up, progress slowed, and it became another corporate welfare scheme.

Then Musk came along and said, "Hey, I've got rich from founding the world's worst consumer bank, how about I give you the first few hits for free?" and hired a few experienced people.

Libertarians rode the back of this and shouted about how much better it would be to privatise space. But in fact we're just right (*) here again, with SpaceX substituted for Boeing.

Re:An

[Anonymous Coward]

Quickly? They took a decade!

Re:An

[Anonymous Coward]

Right, because if you want something done quickly and cheaply you turn to the government! Wait...

Re:An

[the gnat]

Libertarians rode the back of this and shouted about how much better it would be to privatise space. But in fact we're just right (*) here again, with SpaceX substituted for Boeing.

I think you'll find it's not just libertarians cheering for this - after all, privatizing the launch infrastructure has been a key element of Obama's space plans. The difference from the previous situation, where NASA relied on bloated defense contractors, is that SpaceX and its competitors will have to enter fixed-price bids, instead of the old cost-plus contracts which gave the contractors zero incentive for efficiency. Whether this will actually work in the long run remains to be seen, but it's hard to see how this is worse than the old system, and putting the federal government into the launch vehicle business sounds like a spectacularly awful idea.

Re:An

[guruevi]

I don't think you know how these so-called fixed-price bids work for governments. They're not fixed at all as the contract or language implies. They are just starting points for negotiations on more contracts as the scopes and costs change on both ends of the contract.

Basically a government fixed-price request is a very vague description of an idea. The fixed-price bid is a very vague description of a project and associated budget. Whether or not the budget then balloons to eclipse the specified price is irrelevant to the bureaucracy on either side.

Re:An

[the gnat]

That's not consistent with what I've read about this subject. For instance:

...in some quarters outright disbelief remains regarding the launch prices actually posted on the SpaceX website for the Falcon Heavy. No other company has posted fixed launch prices on the Internet — only SpaceX. The actual taxpayer cost of US government launches can only be guessed by calculating from the cost-plus contract costs, which are usually for multiple launches from the same customer. If SpaceX does multiple launches, the posted price would be reduced depending on the number of launches.

Or this:

Rather than the traditional cost-plus model, in which companies are reimbursed the cost of a project plus an additional amount that guarantees them a profit, SpaceX and Orbital are working under newly established Space Act Agreements, in which NASA pays increments of a fixed price once the companies accomplish previously agreed upon milestones.

To reiterate, this is no guarantee that it will actually work better (and not just more cheaply) than the old system. For it to really be a success there needs to be a competitive market, a sustainable business model, and a lack of heavily subsidized competition from the Chinese. But I really hope it does succeed.

Re:An

[khallow]

I like the unintentional "it's far worse than you think" vibe I get off this description.

Basically a government fixed-price request is a very vague description of an idea. The fixed-price bid is a very vague description of a project and associated budget. Whether or not the budget then balloons to eclipse the specified price is irrelevant to the bureaucracy on either side.

The more profit the private side gets, then the more money for bureaucracies on either side either directly through profit or indirectly through bribes and the revolving door. Such things are illegal only if you get caught. This is a built in incentive to balloon costs of projects.

Ever wonder why Congress keeps coming up with cost plus schemes for funding big rockets which use ATK solid rocket motors? Because ATK knows which bureaucracies to bribe.

Re:An

[Anonymous Coward]

The reason why you can have a fixed price contract in this situation is that NASA isn't really defining any requirements; also not changing them midstream; but also that there is little development risk. The rocket from SpaceX isn't really anything innovative, which is actually a good thing, not a bad thing.

Where fixed price contracts don't work is when you have a significant amount of development risk, and you end up having to build that into the cost of the contract, meaning that you often don't end up with low price bids. Europe's ESA for example pretty much only works from Fixed Price contracts, which builds in the cost of that risk into the project, inflating the bid cost, and you end up with Europe overall, not really committing to many projects, because they get sticker shock.

Who can say which method is better overall.

Re:An

[khallow]

What I don't like is the fact that space is becoming increasingly privatised.

Well, why shouldn't it be? Most endeavors in the US are handled privately.

Then Musk came along and said, "Hey, I've got rich from founding the world's worst consumer bank, how about I give you the first few hits for free?" and hired a few experienced people.

Libertarians rode the back of this and shouted about how much better it would be to privatise space. But in fact we're just right (*) here again, with SpaceX substituted for Boeing.

And a considerably cheaper launch vehicle compared to the Delta IV (which Boeing put in the United Launch Alliance rather than continue to fly it themselves). I can't argue with results.

Re:An

[TFAFalcon]

Weren't all rockets built by private companies? So why not let private companies compete against NASA (which is now mostly just a wealth-transfer entity - subsidizing US corporations)

Now that it's been demonstrated that space can be cheaper then what NASA is used to doing, other companies can get in on the game. So NASA will be able to have some options in the selection of their manufacturers.

Re:An

[dudpixel]

Who would choose the words 'nominal' and 'anomoly' for this anyway? Say them both fast and you'd never tell them apart.

Re:An

[Anonymous Coward]

So then when the next set of bids come in, you might get a lower bid from another contractor who has innovated to reduce their risk -- Better parts, new technology etc, and the prices begin to lower over time.

Cost plus == No incentive to lower prices, no incentive to reduce risk, no real incentive to innovate. Sure ESA has higher bids to incorporate the projected risk, but I'd rather have a few re-purposed missions or contractors eating into their profits a bit than less innovation. See also: Solid Rocket Boosters, which NASA didn't really want, but were continued to be used anyway because of the defense contractors who wanted to keep producing the SRBs, and local representatives advocating the SRBs because they "keep jobs in their state" regardless of whether or not their are better alternatives or not.

Re:An

[kellymcdonald78]

To clairfy the contracts that SpaceX and Orbital are operating under for station resupply are neither "cost-plus" nor "fixed price" contracts, they are "fee for service" contracts. NASA pays for certain miletones successfully achieved and cargo delivered to the station. NASA doesn't buy Falcon 9's or Dragons (the Dragon remains the property of SpaceX) they are buying the service (just as they buy FedEx and Airline tickets)

Re:An

[tyrione]

What I don't like is the fact that space is becoming increasingly privatised.

Well, why shouldn't it be? Most endeavors in the US are handled privately.

Then Musk came along and said, "Hey, I've got rich from founding the world's worst consumer bank, how about I give you the first few hits for free?" and hired a few experienced people. Libertarians rode the back of this and shouted about how much better it would be to privatise space. But in fact we're just right (*) here again, with SpaceX substituted for Boeing.

And a considerably cheaper launch vehicle compared to the Delta IV (which Boeing put in the United Launch Alliance rather than continue to fly it themselves). I can't argue with results.

The reason it is `considerably cheaper' is simply due to the fact Boeing couldn't milk the teet any longer while stretching the time line out.

Re:An

[khallow]

The reason it is `considerably cheaper' is simply due to the fact Boeing couldn't milk the teet any longer while stretching the time line out.

Ever thought about why Boeing couldn't "milk the teat" any longer? I don't think it's a coincidence that Boeing got out of the space launch business when SpaceX announced it was getting in. In economics, it goes by the simple label of "competition".

That's what private enterprise and competition brings to this activity. One ca no longer "milk the teat" forever.

Re:An

[hairyfeet]

Which is why we should either manrate the Delta or Atlas rockets or just say fuck it and buy Soyuz off the Russians. I'm sure they'd be happy to take our money, after all many of our rocket motors come from them already, and then we'd have a working solution ready to go.

But sadly that would mean the defense industry couldn't blow through cash like Charlie Sheen blows through coke, we just can't have that. just look at the F22 and F35, trillion dollar turkeys that if we're lucky we'll be able to afford a handful of them and tell our pilots to get in line and they may get a turn flying one in a year or so...sigh, this country is just fucked, isn't it?

Re:An

[bickerdyke]

[...] that SpaceX and its competitors will have to enter fixed-price bids, instead of the old cost-plus contracts which gave the contractors zero incentive for efficiency.

Unfortunatly, the easiest way to increase efficiency is to reduce that expensive, and hardly ever needed thing called "security".

Re:An

[FeatureSpace]

You are exaggerating.

First of all, US government solicitations can be vague or specific. When they are vague, it is intentional in order to encourage a wide variety of proposals. Have a look at: http://www.sbir.gov/solicitations

Now here is where you are very wrong. Bids and proposals are anything but "a very vague description of a project and associated budget". Maybe years ago, in some areas of the US Government this was true. Maybe its still true in a handful of areas. But right the majority of DoD proposals are very specific. I've composed, won and lost SBIR proposals. Vague SBIR proposals are rarely awarded.

Re:An

[ultranova]

What I don't like is the fact that space is becoming increasingly privatised.

Why? All it really means is that launch costs are getting low enough that it no longer requires the resources of a nation-state to do them. Historically, that has marked the tipping point where money starts pouring in and advancements accelerate. So why not let SpaceX's investors pay for further research into the matter? It's not like it excludes anyone else from doing likewise.

Re:An

[Tore S B]

What I don't like is the fact that space is becoming increasingly privatised.

Well, why shouldn't it be? Most endeavors in the US are handled privately.

Well, because the market mechanism doesn't work as well as the public mechanism here - if the US were only able to shed its market fundamentalism and understand that some tasks are optimal for one sector, some for the other. Space exploration is the archetypal community effort - it benefits all of mankind and almost all financial benefits to the country are almost entirely external (research and development yielding advances in manufacturing, engineering, etcetera)

Of course, you might get results because all the people who actually want to get space stuff done will gravitate towards the suboptimal solution, but the optimal solution would just be to lobby for a change in priorities of your national government. For the price of the Afghanistan and Iraq wars you could do the Apollo project between 10 and 40 times over, depending on which estimate you trust, never mind the human cost.

Re:An

[TheSkepticalOptimist]

Why not?

Why should space only be allowed for government use with limitless budgets?

I think that what the governments lack is innovation and a necessity to try and perform on a tighter budget. Governments are not concerned about such mundane things as profit and minimizing operating expenses. If the US wants to go to Mars, then they just jack up taxes and send spacecraft that were invented in the 1950s to Mars.

On the other hand, private corporations have a responsibility to perform on a budget. They have a vested interest in innovation and improving upon the technology that was first introduced in the 50's. Private corporations will open up space for all of us because of a necessity to monetize space, whether for industry, tourism, or science, as opposed to simply firing trillions of dollars up there over the decades with no real benefit or contributions back to society.

Yes initially space will only be available to the 1% at first, but privatizing space gets all of us closer to it then what NASA and other world governments have achieve in the last 60 years of space exploration. Governments have had zero agenda to bring space to the rest of us, and instead waste our tax paying dollars sending a select few to poke around up there, take some space pictures and find out some kind of simple celled organism can survive in a vacuum or there is water on another planet. So what?

Re:An

[khallow]

Well, because the market mechanism doesn't work as well as the public mechanism here

Well, you'll need to give an example then. It looks to me like market works better for this sort of thing.

For the price of the Afghanistan and Iraq wars you could do the Apollo project between 10 and 40 times over, depending on which estimate you trust, never mind the human cost.

And what would you have gotten for that money? At least with the wars, the US knocked over a dictatorship and set back some enemies that were looking to make a habit of bombing stuff on US soil.

Re:An

[Tore S B]

Well, because the market mechanism doesn't work as well as the public mechanism here

Well, you'll need to give an example then. It looks to me like market works better for this sort of thing.

The Apollo space program. All other space exploration too. The Internet. Transistors, fiber optics, radar (and all the high-frequency electronics that come with it). I could go on.

For the price of the Afghanistan and Iraq wars you could do the Apollo project between 10 and 40 times over, depending on which estimate you trust, never mind the human cost.

And what would you have gotten for that money? At least with the wars, the US knocked over a dictatorship and set back some enemies that were looking to make a habit of bombing stuff on US soil.

You also knocked over what conservative estimates place at more than 110 000 innocent civilians in Iraq and 20 000 in Afghanistan. And you can't document those claims.

Re:An

[khallow]

The Apollo space program. All other space exploration too. The Internet. Transistors, fiber optics, radar (and all the high-frequency electronics that come with it). I could go on

I was hoping for an example here. The Apollo program is a program that landed a dozen people on the Moon as well as a temporary space station, and then completely ended. Aside from a little bit of infrastructure in Florida and Texas and some junk on the Moon, there's no trace of the Apollo program any more.

All other space exploration? I suppose it's been great for the contractors, but I don't see much value coming out for the money.

The Internet. Transistors, fiber optics, radar (and all the high-frequency electronics that come with it).

All examples where private enterprise dominates. Keep in mind that most such government-funded activity in these areas is either graft or paying someone to do something that they'd do anyway.

And what would you have gotten for that money? At least with the wars, the US knocked over a dictatorship and set back some enemies that were looking to make a habit of bombing stuff on US soil.

You also knocked over what conservative estimates place at more than 110 000 innocent civilians in Iraq and 20 000 in Afghanistan. And you can't document those claims.

Why use "documentation" when reasoned argument suffices? Prior to about the mid-2000s, Al Qaeda showed a cyclic pattern of attacks versus the US. Every couple of years, there would be a big, high profile attack against US property in allied territory or on US soil. That hasn't been true for some time.

And it's quite evident that the Iraqi invasion removed Saddam Hussein from power.

Whats the problem?

[ZiakII]

The Falcon 9, as its name implies, has nine engines, and is designed to go to orbit if one of them fails. On-board computers will detect engine failure, cut the fuel supply, and then distribute the unused propellant to the remaining engines, allowing them to burn longer. This seems to be the case where that was required, and the computers came through. The engines are also built with protection to limit the damage in cases where a neighboring engine explodes, which appears to be the case here.

Sounds like it did exactly what it was supposed to do.

Re:Whats the problem?

[residieu]

Just because you have a backup plan, and it works, doesn't mean the launch was perfect.

Re:Whats the problem?

[Anonymous Coward]

Which is neither 'smooth' nor 'nominal', though still successful. None of the engines are supposed to fail.

Also nice that they (and we) know about this this soon.

Re:Whats the problem?

[Hentes]

The fact that the rocket had enough redundancy built in doesn't mean that the cause of the failure should not be investigated.

Re:Whats the problem?

[Anonymous Coward]

A nominal launch, then. Anomalynal even, I might say.

Re:Whats the problem?

[beltsbear]

While it is great that the engine out capability worked as planned, this is something you do not want happening often. A failure without an explosion once in 20 flights might be acceptable but the explosion with fragments greatly changes the equation. SpaceX is doing great things and I congratulate them on another success.

Re:Whats the problem?

[mbone]

You really don't want to be having engine burn-throughs, which is what it looks like happened to me. Having one engine of 9 shut down is no big deal, but having one blow is a big deal, even if it didn't take the rest of the system with it.

Re:Whats the problem?

[Richard_at_work]

I don't think it's the fact that there was a failure, or the fact that the system proved resilient, it's the manner in which the failure manifested itself - an engine cutout, a fuel pump failure, or a vibration issue would be cause for a post launch investigation and a pat on the back, while a wholesale engine disintegration will trigger quite a significant inquiry and a heck of a lot of furrowed brows.

It's the difference in magnitude of failure which is the thing to note here.

Re:Whats the problem?

[Maximum Prophet]

Who is saying it shouldn't be investigated? Every launch should be measured and checked.

If you can recover the engines, the unburned parts tell you where they're too heavy, and the burnt through parts tell you where you need more strength.

Re:Whats the problem?

[infidel_heathen]

From TFA:

Falcon 9 did exactly what it was designed to do. Like the Saturn V, which experienced engine loss on two flights, Falcon 9 is designed to handle an engine out situation and still complete its mission.

Looks like even the good old Saturn V rockets had problems with engine loss once in a while.

Re:Whats the problem?

[Anonymous Coward]

As the update to the article from SpaceX points out - the engine didn't blow.

Approximately one minute and 19 seconds into last night’s launch, the Falcon 9 rocket detected an anomaly on one first stage engine. Initial data suggests that one of the rocket’s nine Merlin engines, Engine 1, lost pressure suddenly and an engine shutdown command was issued immediately. We know the engine did not explode, because we continued to receive data from it. Our review indicates that the fairing that protects the engine from aerodynamic loads ruptured due to the engine pressure release, and that none of Falcon 9’s other eight engines were impacted by this event.

As designed, the flight computer then recomputed a new ascent profile in real time to ensure Dragon’s entry into orbit for subsequent rendezvous and berthing with the ISS. This was achieved, and there was no effect on Dragon or the cargo resupply mission.

Falcon 9 did exactly what it was designed to do. Like the Saturn V, which experienced engine loss on two flights, Falcon 9 is designed to handle an engine out situation and still complete its mission.

Re:Whats the problem?

[afidel]

It wasn't an engine explosion, the protective fairing around the engine shattered when the engine cutoff caused a major change in pressure. SpaceX said that they continued to receive telemetry data from the engine which means it did not explode, and in fact was physically intact though not functioning correctly.

Re:Whats the problem?

[Anonymous Coward]

When the Saturn V lost an engine, that engine just turned off. This engine exploded.

Re:Whats the problem?

[MightyYar]

The first outage was during an earlier Apollo with a dummy payload - they actually failed to achieve their planned orbit and had it been a moon launch, they would have had to scrub. But since it was just a test, and since they thought they knew the solution - they called it a success and did not delay the program.

The second outage was, ominously, on Apollo 13.

Re:Whats the problem?

[JustOK]

Rockets EXPLODE!

Re:Whats the problem?

[jamstar7]

As designed, the flight computer then recomputed a new ascent profile in real time to ensure Dragon’s entry into orbit for subsequent rendezvous and berthing with the ISS. This was achieved, and there was no effect on Dragon or the cargo resupply mission.

IIRC, there was no way to recompute a Saturn 5 flight profile on the fly. Remember, kids, that was back in the days when we hunted dinosaurs from the backs of our '57 Chevys. Kudos to SpaceX for having enough out of the box thinking to have the needed software routines in the can already and ready to go. Falcon 9 is more than just another Big Dumb Booster, AAMOF, from everything I'm reading and seeing of its operation, it's pretty goddamned smart. Remember the test flight to the ISS? The first launch attempt, the onboard computers detected a glitch that might have taken out the bird and shut down and aborted the launch right at T -0, even after the humans tapped the buttons authorising the computers to do the launch. Like I say, some serious onboard smarts programmed by some seriously smart people.

Re:Whats the problem?

[MightyYar]

Damn, and they just laid off all their engineers!

Re:Whats the problem?

[Anonymous Coward]

We know the engine did not explode, because we continued to receive data from it.

That in no way means the engine didn't explode. It means all the sensors remained intact after the engine blew up.

Re:Whats the problem?

[Anonymous Coward]

You have two feet, and can survive shooting yourself in one. That's great! It shows the usefulness of redundancy and systems that can redirect fuel away from damaged components to prevent further leakage.

Shooting yourself in the foot is, none the less, not exactly what you're supposed to do.

Re:Whats the problem?

[fyngyrz]

No, the engine did not explode. The fairing around the nozzle was crush by the sudden loss of interior pressure when the engine shut down -- the external pressure was then much higher than the nozzle's interior pressure (no more rocket exhaust) and it got crushed and fell away, harming nothing. The engine is still there, intact, and it did, in fact, just turn off.

Re:Whats the problem?

[Metabolife]

Didn't explode. RTFA

Re:Whats the problem?

[cheater512]

Re-read their reply. It didn't explode (they still received telemetry from the engine).
The debris seemed to be something else, maybe a small part being the engine, but the engine as a whole is more or less fine.

Re:Whats the problem?

[0123456]

When the Saturn V lost an engine, that engine just turned off. This engine exploded.

1. As far as is known, this engine did not explode.
2. Apollo 13 pogo was within a few seconds of causing structural breakup of the Saturn V when the affected engine shut down.

Re:Whats the problem?

[Anonymous Coward]

All launches, regardless of outcome, are thoroughly analysed.

Re:Whats the problem?

[astrodoom]

Actually, according to SpaceX engineers, it did not explode as they were able to continue to communicate with it. The current theory is the outer covering blew off because of the change in pressure.

From TFA: "We know the engine did not explode, because we continued to receive data from it. Our review indicates that the fairing that protects the engine from aerodynamic loads ruptured due to the engine pressure release, and that none of Falcon 9’s other eight engines were impacted by this event."

Re:Whats the problem?

[Anonymous Coward]

Clearly, they need to build the next engine entirely out of sensors.

Re:Whats the problem?

[astrodoom]

*facepalm* the sensors are integrated with the engine. That's like saying your oven blew up but the broiler is fine.

Re:Whats the problem?

[Teancum]

From what can be read between the lines, the engine didn't explode but rather imploded. It shut off at "maximum dynamic pressure", sometimes called simply "Max-Q", when the atmospheric pressure pushing against the vehicle due to its velocity is at the highest it can be at that point in the flight. Between the pressure from outside of the spacecraft and from the nearby engines, the nozzle apparently collapsed in on itself and tore loose, hence the debris.

The engine itself was still there, just missing the nozzle. That is why data was continuing to be sent from the engine and respond to system queries about its status. Had it exploded, those sensors and microcontrollers running the engine would not be in place.

Technically you are correct that all that could be said from the telemetry is that the sensors were still in place, but those sensors would not be registering if it was an outright explosion.

Re:Whats the problem?

[rickb928]

If that's accurate, then SpaceX is looking into a shutdown event, a LOT different than a destructive failure. The fairing imploding will either be the anticipated result, or a new issue to understand and resolve/document.

Shutdown may be accompanied by data, and there is a fix. Valves, pumps, all kinds of fairly well understood stuff to analyze and resolve. Destructive catastrophic failure would be much more disturbing.

So far, they seem to be doing at least as well as NASA did in the early days. Mercury was a real crap shoot, and early Saturn development was exciting to say the least. I filled a few scrapbooks with notes on those faiures. Fun times...

Re:Whats the problem?

[shutdown -p now]

Shooting yourself in the foot is, none the less, not exactly what you're supposed to do.

I'm a C++ developer, you insensitive clod!

Re:Whats the problem?

[Anonymous Coward]

It seems the part that looks like a detonation in the video is just the bell nozzle being torn apart. It was shut down intentionally and the pressure change demolished it. The engine was intact, just not operating properly, and it continued to return data... so I'm guessing they'll be figuring this one out in data, not from burnt pieces of nozzle.

Re:Whats the problem?

[Anonymous Coward]

IIRC, there was no way to recompute a Saturn 5 flight profile on the fly

Unsure about the US technology, but the Soviet N-1 and Proton launchers had control units that could compensate for failed engines or short burns and still put the payload into its orbit. And they were of a similar vintage.

Re:Whats the problem?

[0123456]

The Saturn V used a pitch and roll program early in the launch, then switched to closed-loop guidance. If I remember correctly, the digital computer calculated the ideal orientation to reach the desired orbit and an analogue computer tried to move the operational engines to achieve that. So the capability was limited, but it was there.

Re:Whats the problem?

[DerekLyons]

Sounds like it did exactly what it was supposed to do.

Airbags, when they inflate, and save you from injury in an accident, are doing what they're designed to as well. As is the life jacket that keeps you afloat when you fall overboard. I don't think anyone sane would regard the root cause of their function according to design as anything but a problem. This is the same case, something went very wrong causing an engine to do what it's *not* designed to do - shut itself down in flight. Given the very limited number of these engines that have flown to date, this is something to be very concerned about. By any engineering standards (even the loose ones of space flight which let you call a single flight "proof"), a 1 in (IIRC) thirty failure rate is a Very Big Problem indeed.
 
Or to put it another way - the backup SRB field joint O-ring worked as designed and captured the leakage past the primary O-ring... right up until the day it didn't.
 
It's never good to rely on a backup system.

Re:Whats the problem?

[wisnoskij]

One of the engines was not supposed to fail, the built in redundancy is exactly that a redundancy and should not have been needed.
Space flights and the engineering that goes into building the spacecraft are supposed to be extremely rigorous, such that you do not have entire engines that are so flawed that they fail on their very first flight. How much did this engine cost that did not even work?

Re:Whats the problem?

[fotoguzzi]

Is it possible that a Mission Control technician would have a table with burn times for engine out scenarios and that he could instruct the Apollo astronauts when to manually cut off the engines? As the mission required no earth-orbit rendezvous, how critical would this timing have been?

I have no idea if the astronauts could have done something like turning off the F-1 and J-2 engines from the capsule, but the idea would seem in keeping with the times.

Re:Whats the problem?

[Anonymous Coward]

Whats the problem?

How about payload?
The European ATV can deliver more than 15,000 lb per launch.
In one flight the ATV delivers more than the planned twelve SpaceX flights of 1,000 lb each.
That's pathetic frankly.

Re:Whats the problem?

[SecurityTheatre]

It's reasonable to point out that simply cutting the fuel in a multi-stage hypersonic solid rocket would have fairly catastrophic results.

Can you say, with any certainty, that the engine cutout didn't *cause* the reaction nozzle to shatter and disintegrate?

Under the circumstances (a hypersonic launch vehicle with 9 liquid fueled rockets), a simple engine cutoff procedure seems likely to entail some pretty dramatic material stresses on various components.

From my reading, something like a slight issue with the reaction caused the shutoff, which ITSELF, by the nature of the negative pressure created, caused the nozzle to shatter and disintegrate.

Just a thought...

Re:Whats the problem?

[tsahi]

The Shuttle also had an engine shut down, on STS-51F. It aborted to orbit.

Re:Whats the problem?

[TWX]

But you won't walk in a manner consistent with your species.

If a spider loses an appendage, it'll still walk in a manner similar to the rest of its species.

Re:Whats the problem?

[TWX]

First, what's the cost per unit of payload mass?

Second, what's the value in being able to send up smaller missions, akin to a commuter flight versus a jumbo jet?

Third, what's the redundancy of having multiple functional launch systems worth?

Fourth, what's the value in the US having a launch system of its own without depending on other countries?

Fifth, what's the likelihood that having this launch system prove to be successful will result in the developer working on heavier-lift systems?

When the United States has no launch system we are completely dependent on the Russians for access to a very expensive machine built with enormous cost to us and to all of the other participating countries. Should the Russians decide that they don't want to play anymore, they could simply deny our astronauts access, making the station de facto Russian property. Since the Russians have significantly more station experience than we do, I'm sure that they'd be able to operate it without us.

Our having a launch system, ultimately intended to be man-rated, essentially prohibits that possibility. Same with the Europeans, if they ever have a man-rated rocket. I'm all for that.

Re:Whats the problem?

[quasius]

According to wikipedia ( http://en.wikipedia.org/wiki/Falcon_9 ), the Falcon 9 can deliver 29k lbs to LEO.

Re:Whats the problem?

[notsoanonymouscoward]

Care to update the wiki page? At least according to that....

ATV capable of 7,667kg to orbit.
Dragon capable of 3,310 kg pressurized ( + another 3,310 non pressurized)

http://en.wikipedia.org/wiki/Comparison_of_space_station_cargo_vehicles

Who knows... maybe just maybe NASA is paying for token payloads until SpaceX gets their flight rate up (and thus some notion of improved reliability).

Re:Whats the problem?

[adri]

.. can we please have those scrapbooks scanned and placed online? pretty please?

Re:Whats the problem?

[Anonymous Coward]

Element 29 and 5/8ths, Sensorium, the second toughest hardest martial known to man. The first is Stupidium 287 which is also the densest material known to man.

Re:Whats the problem?

[0123456]

The astronauts could fly the Saturn V to orbit manually, though it was never done. They would probably get to a usable orbit, but I'd guess it was unlikely to be good enough to get to the Moon.

Re:Whats the problem?

[Mass Overkiller]

Oh no the dreaded 8 engine rocket launch

Re:Whats the problem?

[rickb928]

No. Mine.

Re:Whats the problem?

[Dishevel]

What does the cost matter. That is bone by the private company.
What I care about is the cost to the US taxpayer. Seems a a shitload cheaper than what we were doing before.

Re:Whats the problem?

[Algae_94]

flying death trap? That's a bit harsh isn't it. No one is telling you to get into it.

Re:Whats the problem?

[johnny cashed]

None of the Saturn series rockets were "dumb". The booster had its own guidance system independent of the spacecraft's guidance system.

For further reading: http://en.wikipedia.org/wiki/Saturn_Launch_Vehicle_Digital_Computer

Re:Whats the problem?

[jamstar7]

The link says it was on the S-IVB stages, the second or third stage depending on the launch configuration. I'm not finding anything on the guidance for the first stage, though it's certainly possible to run wires down the stage to the first stage of a Saturn 5. The 'runs' would be pretty long, and I'm not sure how they'd handle disconnecting the 'runs'. A quick-disconnect fitting would be susceptable to vibrations and might be a bit tricky to line up to plug in. Solvable, I'm sure, but it'd take a bit of skull sweat...

Re:Whats the problem?

[nedlohs]

And all those times the shuttle O-rings failed but the backup O-ring didn't weren't a problem and just the backups doing what they are supposed to do, right?

Re:Whats the problem?

[johnny cashed]

The computer was fitted to the instrument unit (IU) that was on the S-IVB stage. That computer controlled the stack up until the stage (S-IVB) fitted with the instrument unit was jettisoned. (There abouts anyway, I'm sure there was a "hand-off" to the Apollo guidance computer). Technically the earliest of Saturns had no IU, but they were not manned flights. I believe this was due to the IU still being in development. Here is more on the IU:

http://en.wikipedia.org/wiki/Saturn_V_Instrument_Unit

Re:Whats the problem?

[tyrione]

We don't have a launch system, presently operating, because the GOP doesn't want to invest in it and downsize the Military Industrial Complex.

Re:Whats the problem?

[Anonymous Coward]

I'm not sure if you are as stupid as you sound but here we go:

First, what's the cost per unit of payload mass?

Isn't it generally true the rule being cost per unit decrease with volume? With the European currently enjoying a 15:1 volume advantage.
And at $140M per launch (ahem, not the lowball $54M bullshit), SpaceX has no cost advantage, while it lobs packing peanuts into space.

Second, what's the value in being able to send up smaller missions, akin to a commuter flight versus a jumbo jet?

Value of smaller missions? None in this case. See the point above.

Third, what's the redundancy of having multiple functional launch systems worth?

You can have this one.

Fourth, what's the value in the US having a launch system of its own without depending on other countries?

I'd give you this one too except a 15:1 advantage in favor of a competing system means you are doing something wrong.
Would you buy a riding lawnmower from GM, if you can have a diesel pickup truck for the same price from Ford?

Fifth, what's the likelihood that having this launch system prove to be successful will result in the developer working on heavier-lift systems?

I'm not interested in paying $140M per launch so SpaceX can go through toilet training.

 

When the United States has no launch system we are completely dependent on the Russians for access to a very expensive machine built with enormous cost to us and to all of the other participating countries. Should the Russians decide that they don't want to play anymore, they could simply deny our astronauts access, making the station de facto Russian property. Since the Russians have significantly more station experience than we do, I'm sure that they'd be able to operate it without us.
Our having a launch system, ultimately intended to be man-rated, essentially prohibits that possibility. Same with the Europeans, if they ever have a man-rated rocket. I'm all for that.

I didn't even bring the Russians into this.
The European ATV is human-rated.

Re:Whats the problem?

[camperdave]

Au contraire! It is always good to rely on a backup system, however, it is never good to have to use them. As you point out, the systems keep us safe. And further, the engine *most certainly IS* designed to shut itself down (or rather, be shut down by the flight control computer) in flight. It is not a nominal function, but it is a normal safety feature. The Falcon 9 did exactly what it was supposed to do in the event of an engine anomaly: shut it down and go for a longer burn on the remaining engines.

Of course, the real issue is what was the cause of the anomaly and what can be done to prevent a recurrence.

Re:Whats the problem?

[Anonymous Coward]

Time to go on kerbalspaceprogram.com and make your own engine explode, I guess

Re:Whats the problem?

[zbychu900]

| Soviet N-1 and Proton launchers had control units that could compensate for failed engines or short burns and still put the payload into its orbit.
Except that it never worked on the N-1 - all the launches resulted in catastrophic failures (http://en.wikipedia.org/wiki/N1_%28rocket%29)

Re:Whats the problem?

[Anonymous Coward]

29 kilopounds?

Re:Whats the problem?

[Chris Burke]

flying death trap? That's a bit harsh isn't it.

Yeah, it's almost like they're a troll spouting unsubstantiated FUD.

I love that their "proof" of SpaceX covering up a failure is that their defamation suit against the person claiming this was the case was settled out of court.

Re:Whats the problem?

[TWX]

I don't see how ATV is human-rated when they deorbit and burn them up to get rid of them...

Re:Whats the problem?

[JTsyo]

The Falcon 9, as its name implies, has nine engines, and is designed to go to orbit if one of them fails.

they lucky it worked as it did. Imagine if one didn't fail and they couldn't get into orbit.

Re:Whats the problem?

[Anonymous Coward]

From what can be read between the lines, the engine didn't explode but rather imploded. It shut off at "maximum dynamic pressure", sometimes called simply "Max-Q", when the atmospheric pressure pushing against the vehicle due to its velocity is at the highest it can be at that point in the flight. Between the pressure from outside of the spacecraft and from the nearby engines, the nozzle apparently collapsed in on itself and tore loose, hence the debris.

That's a rather unlikely interpretation. SpaceX has claimed that the debris was pressure relief blowout panels of some sort, not the engine itself. That makes a lot more sense than assuming an engine nozzle would collapse in on itself just because it stopped firing.

Think about it. A rocket engine's combustion chamber, nozzle, and expansion bell are all designed to contain very high pressures without rupturing. As a result, they're circular in cross section, that being the strongest possible shape under tension.

What happens if that same structure resists crushing force instead? Crumpling up is not likely. Circular cross section structures made of metal are typically even stronger under compression. Also, the pressure differential trying to crush a shut-off engine is much less than the pressure trying to explode an operating engine. Probably by multiple orders of magnitude.

Max-Q is a red herring here, by the way. Max-Q is maximum dynamic pressure, the extra pressure experienced by a surface moving through a gas. Aerodynamic surfaces (and the structures which support them) have to be strong enough to withstand predicted Max-Q for any given mission. Engines are generally shrouded by aerodynamic fairings and shouldn't experience much dynamic pressure.

My guess about the failure: It sounds like SpaceX designed containment cells to limit the chance that debris or overpressure from one engine failure could damage another. It's impractical to build containment cells strong enough to withstand absolutely any failure -- their walls would have be at least as strong as combustion chamber walls, and that's far too much weight. Instead, they probably have rear-facing blowout panels, designed to fail first and expel gas and debris to the rear. Some sort of failure released enough pressure into that engine's cell to blow out the panels, some debris was expelled to the rear as intended, and and an automated fuel cutoff system shut down the engine.

Three guesses off the bat

[Anonymous Coward]

1. The Doctor
2. MIB
3. Decepticons

Re:Three guesses off the bat

[R3d M3rcury]

4. USS Enterprise, researching this time period.

not really a bad thing

[wierd_w]

The engine failure of the falcon 9 engine #1 is not really a bad thing. It served to prove the reliability of the shutoff system, and flight control hardware.

Considering the horrendous failure rate of NASA's early engines, (the kind that explode spectacularly), this managed failure situation is very promising.

Rest assured, there will likely be a strong inquiry concerning the manufacture and design of the engine fairing that failed, causing the pressure drop, and engine shutdown.

Managed failures like this one don't speak poorly of spacex. On the contrary. They show spacex planned ahead, and the failsafes they built actually work.

Re:not really a bad thing

[Captain.Abrecan]

"Considering the horrendous failure rate of NASA's early engines, (the kind that explode spectacularly), this managed failure situation is very promising." frigging spectacular you mean. Damn good work.

Re:not really a bad thing

[Anonymous Coward]

I agree, it's not really a bad thing. However..

Quote: "...the failsafes they built actually work."

Technically, are these safety systems on the rocket considered fail safe? Can a rocket fail-safe? Fail-safe refers to things like train brakes or elevators that won't move without power. A mechanism continuously applies the brakes whether the power off or on (like a spring) and it takes a continuous counter force to release the brake (releasing the brake pedal). So if the power fails the elevator or train will return to a safe mode, aka braked.

Re:not really a bad thing

[Virtucon]

Not just Early Engines..

Let's see, there was the Titan IV which took out a facility at Edwards AFB on April Fools Day in 1991. Now that was an Air Force engine, but fairly modern. There was another Titan IV which exploded in more spectacular fashion.

Recently, we have the NASA Morpheus Lander Explosion.

Then there's the Delta II, which is a newer launch system which has exploded at least twice that I'm aware of. Once in 1995 and another in 1997.

The point is that NASA and the Air Force and their various subcontractors, SpaceX not included, don't have a perfect record on launch vehicle malfunctions. You can't have lots of propellant with oxidizer burning without some sort of malfunction. While still rare, these events can and do happen and it's good to see SpaceX plan for these kinds of things unlike the Soviets did when their Moon Rocket went "boom" when they were testing in the 60s In Fact, all four launches of the N-1 were failures.

Re:not really a bad thing

[wierd_w]

I don't have access to the falcon 9's engineering data, so I can't comment definitively; take with copious salt.

A rocket engine is basically a fuel supply line coming from some fuel tanks, being injected under pressure into the reaction chamber, nestled inside the burn cone.

A failsafe system would clamp down fuel and oxidizer supplies at multiple points along the supply to ensure that neither reaches the reaction vessel in the event of a flow, pressure, or reaction anomaly. Such systems would need to be very robust, as a catastrophic failure of the reaction chamber wuld tend to destroy hydraulic lines and cause all manner of hell in there.

As such, I would expect such a system to be very "spring loaded" and "unpowered", if not activated by anomalous conditions directly. (Pressure drops, failsafe system deploys from pressure change as a purely mechanical safegard.)

Re:not really a bad thing

[TWX]

No, failsafes refer to a designed-in failure method that is not catastrophic to the whole assembly.

Some engines, like turboshaft engines, have an intentional narrow point in the driveshaft designed to fail under the right circumstances. If something's got to give, make it something that fails without either destroying the machine outright or else killing the occupants.

A rocket design that manages to avoid destroying the vehicle when an engine explodes definitely qualifies as fail-safe.

Re:not really a bad thing

[EvanED]

Not to take anything away from SpaceX, but to the extent that you mean to suggest "SpaceX did a better job than NASA did early on" (which may be none at all), it's of course not really fair to compare considering that SpaceX didn't exactly throw out the knowledge that NASA and others built up because of those failures.

Re:not really a bad thing

[wierd_w]

This is very true, but if you've ever worked in aerospace, you surely know about "tribal knowledge."

SpaceX would have started with a clean slate in that department, and without NASA's tribal knowledge... let's just say that I am very pleased with their performance.

Re:not really a bad thing

[Teancum]

The interesting thing is what may be a failure of the orbital insertion of the Orbcom satellite that was supposed to use the 2nd stage of the Falcon 9 for an additional burn after separation of the Dragon. Apparently either due to this engine loss of the 1st stage or some other problem, that satellite didn't get to the desired orbit.

It will be interesting to see if SpaceX will refund Orbcom their money or do something extra to help them out.

Re:not really a bad thing

[Kjella]

I think that highly depends on whether there's any more engine failures on the next flights. If it seems like an odd case and SpaceX can say that "and even such a thing were to happen again, we'd catch it" then all is well. If another one fails and it smells more like "our engines aren't exactly 100% reliable, but we're betting on statistics that two of them won't fail on the same flight" then that's not good.

Re:not really a bad thing

[Electricity Likes Me]

I was under the impression that SpaceX had poached a ton of former NASA or support company people?

Re:not really a bad thing

[wierd_w]

If the ascent vector isn't correct, (which it wasn't, due to the failure), then the entry vector for the capsule will be different from the one planned. This is the likely cause of the orbcom deployment snafu.

It's basic geometry. The angle changed, so the insertion point changed. (The tangent intersection of the satelite orbit relative to the ascent vector) That's why the sat isn't in the proper place.

Re:not really a bad thing

[TubeSteak]

Rest assured, there will likely be a strong inquiry concerning the manufacture and design of the engine fairing that failed, causing the pressure drop, and engine shutdown.

You've got the chain of events backwards.
A loss of fuel(?) pressure forced an engine shutdown, which caused a pressure drop at the engine's nozzle, which caused the engine fairing to fail.

Re:not really a bad thing

[wierd_w]

That makes sense...

I'd hold off on speculation until after forensic evaluation of the failed component (if it doesn't burn up in re-entry), and failure data sent from the vehicle. All we know for sure is that the safety kicked in, and the engine shut down.

I would expect a full inquiry as to why this happened. That's all.

*shrug*

Re:not really a bad thing

[DerekLyons]

The engine failure of the falcon 9 engine #1 is not really a bad thing. It served to prove the reliability of the shutoff system, and flight control hardware.

The numerous failures of the primary O-ring on the SRB's "proved" the reliability of the backup O-ring too. The numerous near (but not complete) failures of the back-up O-ring "proved" it was reliable too.
 
Right up until the 25th time...

Re:not really a bad thing

[Anonymous Coward]

Now that was an Air Force engine

Huh? The Air Force doesn't design or build engines. It was an Aerojet LR-87.

Re:not really a bad thing

[Teancum]

It was more likely that the 2nd stage needed to burn longer for the deployment of the Dragon due to the failure, thus didn't have the fuel reserve necessary to achieve the proper orbital geometry needed for the Orbcomm satellite. Enough fuel (thus delta-v) could have compensated for the problem, but it simply wasn't there. Originally the apogee was supposed to be about 700 miles, but only achieved about 300. There is some on-board fuel for the Orbcomm satellite to try and compensate, but this is likely too much of a difference for them to effectively "fix" the orbit.

Neither SpaceX nor Orbcomm have commented about the snafu. Apparently the satellite was supposed to be just a testbed anyway and not something in their working constellation, but it still is egg on the face of SpaceX in terms of being able to deliver payloads.

At the very least, if I were Elon Musk I would end up offering a "free" flight for another satellite for Orbcomm in the future... if they would take it. Even though it was a secondary payload, Orbcomm did pay good money for the flight and were expecting the performance that SpaceX has been claiming for some time of "100% reliability to meet all mission objectives".

Re:not really a bad thing

[Teancum]

SpaceX has poached a whole bunch of people from across the entire aerospace industry, but in some cases they've had to re-learn lessons that should have been known about in the past from previous spaceflight missions.

Still, SpaceX seems to learn from their past mistakes and shows a remarkable ability to refine their future designs very well... generally not repeating the same mistake twice. That there are thousands of other mistakes to make still should give pause for concern, but I highly doubt you will ever see another SpaceX flight with an engine failure like this one again in the future.

Re:not really a bad thing

[eugene6]

If they're ex-employees, it's not called poaching.

Re:not really a bad thing

[Teancum]

Let's see how SpaceX reacts to this incident. Yes, a backup system or a safety system was used when it shouldn't have even been touched, but it is nice that such was in place to prevent an even larger disaster.

What NASA did in terms of their "go fever" to keep launches happening in spite having the primary O-rings burn through was to simply ignore the issue altogether and treat the backup systems as something to be used in a normal flight. It should be treated instead as a canary passing out in a mine where it is time to make some serious changes before it is too late.

Even if the Dragon splashes down with a genuinely successful mission returning all of the cargo that is supposed to come down and delivering all of the cargo expected on the ISS, this flight should have a through accident review board and engineering review befitting of a loss of vehicle investigation... as SpaceX should have lost this rocket yesterday. They really need to find out why they didn't lose the vehicle as well as why they came so close as well.

Re:not really a bad thing

[Nethemas the Great]

Actually there was nothing preventing the Orbcom sat from being inserted into the proper orbit but for rules by NASA and their ISS partners (Russians) that told them that they were not allowed to reignite the second stage because of the malfunction in the first stage.

Re:not really a bad thing

[Nethemas the Great]

There was nothing wrong with the insertion. The Falcon 9 actually shuts down two engines during late flight of the first stage so as to not exceed 5g acceleration anyway. The reason the sat didn't get into it's proper orbit is because they weren't permitted to perform the required re-igniting of the second-stage after sending Dragon on it's merry way due to rules placed upon them by NASA and co. the first-stage engine out (see above for links).

Re:not really a bad thing

[Matt]

Neither SpaceX nor Orbcomm have commented about the snafu.

Orbcomm has in it's latest press release: Orbcomm Launches Prototype OG2 Satellite. OG2 satellite's insertion orbit lower than expected.

" ...the rocket did not comply with a pre-planned ISS safety gate to allow it to execute the second burn."

I haven't read anywhere exactly what that means.

Re:not really a bad thing

[ConfusedVorlon]

A perfect record might be a really bad sign.

It may tell you that you are massively overengineering your solution, and that therefore your cost is higher than it needs to be (or your capability lower than it needs).

We can build cars that are much more resilient to crashing, but at some point, they become too slow, too heavy, too expensive and they're only really useful as tanks.

Re:not really a bad thing

[mbone]

Translation : They couldn't guarantee that it wouldn't hit the ISS (or, more exactly, avoid a safety buffer around it), so they couldn't do the burn.

An upper stage may have a short time window where they can re-ignite (batteries run out, cryogenics will eventually boil off, etc.), so they may be out of luck.

Re:not really a bad thing

[Teancum]

In other words it was politics, not engineering or science that kept the Orbcomm satellite from getting into the previously agreed upon orbit.

Nice. There may even be some logic to the notion so far as the Merlin 1-C engine should be considered defective until proven otherwise or at least the cause of the malfunction identified clearly.

Re:not really a bad thing

[skogs]

I agree completely. I believe this is proof of evolution in the rocketry business. This is an extra level of failsafe designed into the system, allowing work to still be accomplished.

Had this been any previous launch vehicle, it would have had to abort and splash down in the ocean somewhere because it wouldn't be able to compensate and continue on.

Re:not really a bad thing

[tyrione]

No one expects the pioneering research to provide a perfect record. Yet, one would expect after you get to stand on the shoulders of giants your record shouldn't start out with a record of failures, but then again those expecting perfecting in Engineering and Science don't understand either one.

Re:not really a bad thing

[tsotha]

Well, that and it's been fifty years since NASA started playing with engines in earnest. There's no way they could have loaded everything up with sensors the way we do today - you can usually figure out what went wrong from the telemetry even if the engine is totally obliterated and sinks to the bottom of the ocean. That saves a lot of time in development, and it also allows you to look at a successful flight and say "hey... that number is only 60% of what we expected" or "the shutdown transient is big enough to damage the engine we're planning to use for tail landings later" or "this part of the rocket isn't supposed to get hotter in this phase of the flight".

The fact that SpaceX may have built a reliable rocket more quickly than NASA doesn't really surprise me. What surprises me is guys with slide rules were able to build a rocket that worked at all using high-speed cameras and primitive telemetry. A few countries around the world still can't get this right even using known-working designs as patterns.

Re:not really a bad thing

[tsotha]

I don't think they can really afford to launch again until they've determined the root cause of the failure. Presumably there are multiple ways an engine can fail, and you'd rather not be in the position of having two engines fail from different problems if you could have done something about it. We're not talking about a weapon system during a war where those kinds of things become acceptable risks.

Re:not really a bad thing

[camperdave]

Right up until the 25th time...

Right up until the 25th time... when the O-rings were chilled below their design temperature and operated out of spec. You can't use the Challenger disaster as a poster child for backup failure because the system was compromised and abused.

Re:not really a bad thing

[Lucractius]

I think the more fundamental question revolves around the difference between the rocket engines being 'fail-safe' and the rocket itself as a whole being 'fail-safe'.

The engines are clearly designed to be as fail-safe as they can make, complete with efforts to reduce the effect of an entire engine undergoing a violent, uncontrolled, rapid, exothermic dis-assembly. Its fail-safe in a unit test fashion.

The rocket as a whole however... is only partly fail-safe. Its designed to automatically react to faults (eg: that launch pad self abort), handle 2 dead engines and can as evidenced definitely handle 1 dead engine, its even designed to limit the impact of an engine exploding so it doesnt kill the other engines. There is a lot of work making sure individual failures dont destroy the rocket one way or another.
But once its airborne, I am not aware of any launch abort that qualifies for the term fail-safe (correct me if I'm wrong, I love knowing how awesome the guys at SpaceX are). Once the ignition takes place and its airborne, I am aware of only 4 possible final outcomes, none of which is truly fail-safe in terms of mission success (payload to orbit safe, payload in the air safe, or payload on the ground safe).

These only refer to the scenarios after liftoff. Pad auto abort is clearly a fail-safe state (barring the rocket exploding on the pad lol)
1 => Launch runs ok - 'the rocket' did not fail to place its payload in orbit, - No failure - Not fail-safe
2 => Launch successful, but with anomaly eg: 1 engine failure - 'the rocket' did not fail to place its payload in orbit - No failure - Not fail-safe
3 => Launch failure, rocket goes out of control kerbal style, destroys itself without outside intervention, eg: nosedives into the Atlantic or shreds itself while airborne, - 'the rocket' failed to place its payload in orbit - Failure - Not fail-safe
4 => Launch failure, rocket suffers from an issue requiring the Launch Control team to initiate a self destruct abort, - 'the rocket' failed to place its payload in orbit - Failure - Not fail-safe

So while various parts are fail-safe I dont think we can qualify the rocket itself as fail-safe once its airborne, only while on the pad. Liftoff seems to be the moment the launch passes beyond the fail-safe point at present excluding the future possibilities of the planned powered reusable return stuff and the launch abort escape system which isn't used for regular satellite launches (would be awesome if it was, since normally its either orbit or explode for commercial satellites).

Just my thoughts.

Re:not really a bad thing

[camperdave]

No slate is ever clean from the accumulated knowledge of previous designs. SpaceX didn't design an engine from scratch. The operating principles of a gas-generator power cycle rocket engine would be known, for example, as were the operating principles of a pintle injector.

Re:not really a bad thing

[DerekLyons]

Actually I can - if you read what I wrote and are actually familiar with the Challenger accident and the history behind it rather than just parroting the soundbite version.
 
Short version: The primary O-ring leaked fairly consistently even at temperatures within the design limits. (Contrary to popular belief, there were not actual specs or hold/abort limits based on O-ring temperature. Just design limits that were never fully formalized into flight criteria.) So, they added a secondary O-ring, and once they started flying... it too showed signs of damage and near failure even at temperatures within the design limits. But it never actually failed - so they declared it safe to fly... With results known to all.
 
The moral of the story is that if you rely on a backup - you essentially don't have a backup, and have reduced your defenses from two lines to one.

Re:not really a bad thing

[toruonu]

Why do you claim that they should have lost the vehicle? A failure of one engine out of 9 is something that the system was designed to handle. And the fact that it was designed to handle this doesn't mean that it's considered normal operation. Your car has an airbag designed to handle an accident, this doesn't mean that accidents will be normal operation.

In fact as mentioned multiple times already the Falcon 9 switches off two rockets at a late phase of the launch to avoid exceeding 5g acceleration, therefore the loss of one subengine wouldn't cause a loss of vehicle.

Yes, they will investigate it thoroughly and understand what was the cause and wether it needs fixing (1C will only make one more flight afaik) or if this has already been addressed in Merlin 1-D or Merlin 2, but in no way should you claim that the vehicles success was a crazy luck accident.

Re:not really a bad thing

[metaforest]

Had this been any previous launch vehicle, it would have had to abort and splash down in the ocean somewhere because it wouldn't be able to compensate and continue on.

IIRC the shuttle system could tolerate losing a main engine and still reach targeted orbit. As some one pointed out earlier in one of the branch threads, it actually happened on a launch late in the program.

Re:not really a bad thing

[skogs]

Learn something new every day I guess.

Perfectly unperfect.

[Anonymous Coward]

If you sell your system as being fail safe you can market it two ways.

1. Trust us it's fail safe.

2. Told you so.

Yeah, they had a engine fail, but the system shut it down and the other engines compensated. You've got data from the failed engine and you've got the assurance that your system works sans 1 engine. This outcome only makes SpaceX better.

Not all the info

[Antipater]

TFA only tells half the story. MSNBC has more. Dragon is fine, but it's possible that the launch's secondary objective, which was to put the first of an 18-satellite telecom array into a tricky high-inclination orbit, went a little screwy as well, and the sat isn't in the proper orbit at the moment. Details are still being dug out.

Re:Not all the info

[zrbyte]

Well apparently the SpaceX update in TFA says otherwise:

there was no effect on Dragon or the cargo resupply mission

Re:Not all the info

[Antipater]

Dragon is fine, but...

Did you miss that part of my post? The telecom satellite is separate from the resupply mission.

Re:Not all the info

[Anonymous Coward]

The Orbcomm satellite is a technology demonstrator prototype for their upcoming 18-satellite telecom array. While it might not have achieved the correct orbit it will most likely serve its purpose. However since it was piggybacking on another mission it's unlikely they will tell us much. It's something between SpaceX and Orbcomm. Maybe Orbcomm will give a presser but it won't be as part of any NASA briefing.

Re:Not all the info

[0123456]

Apparently the second stage didn't hit the required orbit for NASA to allow them to restart it without risk of collision with ISS if something went wrong. So it looks like SpaceX could have restarted the stage but NASA didn't let them; it was a consequence of the first stage engine failure, not a second failure.

Re:Not all the info

[Teancum]

Failure to reach the orbit that SpaceX claimed that they were going to put the satellite into is to me massive egg on the face of SpaceX and will make it harder to sell future flights unless they can provide some assurance that even the secondary payloads will be able to meet mission objectives.

While SpaceX may also be able to claim that the Falcon 9 is still in "shakedown mode" and they are trying to work out the bugs, that doesn't help sell flights. There should have been enough reserve fuel to send even the secondary payload to its ultimate destination even if there was a bit of a snafu along the way.

Then again, this is linked to the fact that the Falcon 9 "version 1.0" (which is the current version) has barely enough fuel to launch the Dragon to the ISS empty, much less with any extra cargo or secondary payloads. The next version of the Falcon 9 as well as the Falcon Heavy is going to have that sort of extra margin of fuel necessary to be able to compensate if something like this happened, but it will be a hard sell to future customers.

Re:Not all the info

[0123456]

Failure to reach the orbit that SpaceX claimed that they were going to put the satellite into is to me massive egg on the face of SpaceX and will make it harder to sell future flights unless they can provide some assurance that even the secondary payloads will be able to meet mission objectives.

Except it appears that the only reason for the 'failure to reach orbit' was that NASA said they couldn't restart the engine due to the possibility of hitting ISS if something went wrong. That only applies to flights to ISS, not to satellite launches.

Re:Not all the info

[Teancum]

Perhaps SpaceX is biting off more than they can chew by trying to double up with secondary payloads for ISS flights.

Re:Not all the info

[zrbyte]

Yeah. You're right. I did miss it.
Here's some more info and a statement from Orbcomm about the satellite. It is indeed in the wrong orbit.

The importtant things

[Samantha Wright]

– Both Saturn V and the shuttle launch system were designed to handle failure of at least one engine
– The entire engine didn't actually explode, as some sources have reported; the onboard computers were still sending data from it (SpaceX believes it was just the aerodynamic casing (fairing) that exploded, due to the pressure release of the engine)
– This doesn't mean the Falcon 9 system is necessarily less safe than NASA systems; on two occasions, Saturn V rockets experienced a similar loss, with similar (i.e., nil) impact to the mission's success

So, y'know. Rejoice nerdily about the fact that the failsafes worked, rather than worrying about commercial technology being inferior.

Re:The importtant things

[Anonymous Coward]

"Pressure release" is as much an explosion as an "uncontained failure" of a turbofan.

Re:The importtant things

[Maximum Prophet]

Both Saturn V and the shuttle launch system were designed to handle failure of at least one engine...

The shuttle can get to orbit with just two of the liquid fueled engines, but was designed to return with just one. Turns out, you can deorbit a shuttle with just the maneuvering jets.

Unfortunately, a failure of the solid fueled boosters, is mostly fatal.

Re:The importtant things

[jamstar7]

The shuttle can get to orbit with just two of the liquid fueled engines, but was designed to return with just one. Turns out, you can deorbit a shuttle with just the maneuvering jets.

Unfortunately, a failure of the solid fueled boosters, is mostly fatal.

I'm thinking that's because the orbiter was bolted onto the side of the launch vehicle. I'm thinking, if it would have been mounted on top like a normal capsule, it probably wouldn't have killed that crew. But hey, IANARS, so my opinion means shit.

Re:The importtant things

[0123456]

I'm thinking that's because the orbiter was bolted onto the side of the launch vehicle.

To a large extent it's because it had wings. If you need wings to land and they fall off, you die.

Surviving a launch accident in a winged rocket is very hard, because you have to get from flying vertically to flying horizontally at supersonic speed without anything falling off. Normally the best you can do is fit ejection seats and cross your fingers as you pull the handle.

The X-20 with an escape rocket below the spacecraft was probably the closest to being survivable and the tests for that looked pretty hairy.

Re:The importtant things

[Anonymous Coward]

"Pressure release" is as much an explosion as an "uncontained failure" of a turbofan.

I've always been partial to "spontaneous disassembly".

Re:The importtant things

[Electricity Likes Me]

Not really. An explosion - i.e. a detonation - is a very specific type of event with very specific and disasterous consequences. A pressure release is not necessarily a detonation.

Re:The importtant things

[bill_mcgonigle]

due to the pressure release of the engine

I read this in the official statement too - I'm guessing it makes perfect sense to rocket scientists.

My best guestimate: because of the sudden lack of exhaust gasses from the engine, the pressure inside the fairing changed extremely significantly and quickly, and the fairing couldn't take the pressure delta, so it ripped apart.

Somebody correct me.

Re:The importtant things

[Anonymous Coward]

I do agree with your point, but facts are facts...

– This doesn't mean the Falcon 9 system is necessarily less safe than NASA systems; on two occasions, Saturn V rockets experienced a similar loss, with similar (i.e., nil) impact to the mission's success

On one occasion (Apollo 13), the second stage lost one engine, and the impact was nil, but in the other instance, Apollo 6 lost two second-stage engines and was unable to make its planned orbit.

Re:The importtant things

[Anonymous Coward]

Tell that to the early De Havillan (sp?) comet air crash victims. A anomolous pressure release can be also be interprited as an 'explosive decompression' y0.

Re:The importtant things

[bsane]

The shuttle can get to orbit with just two of the liquid fueled engines, but was designed to return with just one. Turns out, you can deorbit a shuttle with just the maneuvering jets.

Depends on when the failure occurs- there was an 'abort to orbit' where they lost an engine fairly late in the launch, and they continued to an acceptable, but not planned orbit. Losing an engine and still getting to the hard to hit space station is impressive. Most of the shuttles abort modes when losing an engine involved dropping the solids (and/or tank) and landing somewhere.

Re:The importtant things

[Anonymous Coward]

It was mounted to the side for a reason. The stack would have been unsafe with a vehicle that size and of that mass on the top of the stack.

It was a design compromise that was driven by the requirement for the space shuttle to not only be a crew vehicle (early designs were mostly designed to be crew vehicles because the Saturn V was intended to still be in production), but also a cargo vehicle. While the US Air Force requirement defined the length, the cancellation of the Saturn V and the termination of all work by the Nixon administration cancelled all plans for the space station, even if the shuttle didn't have that US Air Force requirement, it probably still would have been the size and shape it was, because NASA realized that the diameter had to be as large as it was (this wasn't the US Air Force that defined that, they only specified the length of the payload bay) in order to function as a work lab.

It is difficult to say if there would have been a difference in survivability if the vehicle was placed at the top of the stack though. If that were the decision, the design more than likely would have been completely different, and as a result having different properties. NASA's accident survivability studies however pretty much require that the initial boost phase go as planned, so any event that would cause a LOV event during that phase (the first few minutes where the SRB's were being fired), would essentially also mean a loss of crew.

Initially NASA did studies to engineer a way to shut down the SRB's during ascent, but it was determined that there would be no way to shut down both boosters simultaneously, and the asymmetrical thrust alone would have more than likely caused a Loss of Vehicle.

Re:The importtant things

[Anonymous Coward]

unless you have actually worked on the engine, it would be impossible to comment definitively, but my suspicion is that the engine itself requires a specific pressure balance between what is inside the engine and what is external to the engine. Think of a submarine, (or the space station), they are designed to function with a specific pressure balance, and if that doesn't exist, you could have either an implosion or an explosion, or just a physical destruction with debris of the engine rather than an outright explosion. So the engine is operating with a high positive internal pressure, the engine shuts down, and that positive internal pressure is now gone because you no longer have fuel/oxidizer flow.

Another thing is that there appears to be a containment structure between the engine and the 'outside' on the Falcon rocket, and it may have just been this structure that was damaged as a result of the anomaly, not the engine. The above scenario could explain what happened as well, but the pressure difference would be between inside that containment structure and the outside, with the pressure inside the structure being a result from an engine bleeder valve.

Again, without someone who worked on the engine explaining it, it is all just largely guess work.

Re:The importtant things

[Anonymous Coward]

on the other hand, there was only one premature ssme cutoff in the
entire shuttle program!

Re:The importtant things

[Anonymous Coward]

All shuttle abort modes worked under the assumption that you had an intact vehicle until after the solids were jettisoned. There was nothing that could be done while they were still firing, and they are jettisoned when they are still firing, so all the abort modes were 'post SRB jettison'

Re:The importtant things

[mbone]

– Both Saturn V and the shuttle launch system were designed to handle failure of at least one engine

Yes, and at least one Apollo launch had an engine failure (Apollo 13). At the time it didn't seem like too big a deal, but they could have lost the mission and the crew.

Re:The importtant things

[camperdave]

I'm thinking that's because the orbiter was bolted onto the side of the launch vehicle.

The orbiter *WAS* the launch vehicle. The external tank was, in essence, a giant drop tank, similar to what you might find on long range aircraft. The SRBs were not fuelled by the tank, and (theoretically) could have been mounted to the shuttle beneath the wings on disposable pylons. They could even have been mounted above the wings. However, they were mounted to the external tank, probably for force and mass distribution convenience.

Re:The importtant things

[rufty_tufty]

No the reason it's strapped on the side was so that the main engines (at the time of design viewed as the expensive bit) could be returned and re-used. The only way to do that was to have the engines as part of the orbiter. This meant any detachable fuel tank had to be either at the top of the stack or on the side.
The wings were there to provide the cross range capability, the original shuttle design was a lifting body i.e. no wings.

This is good news

[Anonymous Coward]

I am actually very glad to see this. The ship is designed to have redundancy with nine engines allowing for at least one failure (I thought I had read it could handle 2 losses somewhere but I cannot find a source). So the fact that it actually continued its mission with one lost engine proves the engineering is sound.

Over time, they'll figure out what causes the failures and correct the problems. But in the meantime, it is nice to know it can survive losing an engine.

-MyLongNickName

Re:This is good news

[Anonymous Coward]

Yeah, you look at it one way and they just had a massive real-world test of their capabilities and they passed.

One of their neighbors fell apart with shrapnel flying everywhere and the rest of the engines were like:
LIKE I CARE, WE'RE GOING TO SPACE MOTHERFUCKER!

Looks like we've had our glitch for this mission

[Joe_Dragon]

Looks like we've had our glitch for this mission

It was a good launch

[Maximum Prophet]

Pilots say any landing you can walk away from is a good landing.

In space, any launch that accomplishes its goals is a good launch. If good costs 10% of perfect, go for good.

Re:It was a good launch

[Anonymous Coward]

What is the failure rate of good? What is the cost of failure? These questions need answers before you can draw that conclusion.

Re:It was a good launch

[TWX]

Obviously SpaceX wants to achieve man-rating so that they can launch and return personnel in addition to the cargo runs they're currently beginning. I'm curious as to how this moderate malfunction will impact the rest of the program.

Bearing in mind, of course, the deaths of Chaffee, Grissom, and White in the Apollo 1 accident, the launch-time engine failure and later unrelated catastrophic failure for Apollo 13, the Challenger disaster, and the Columbia disaster, it's difficult to call SpaceX's anomaly as being any worse than those. If SpaceX manages a series of cargo deliveries without any loss of the capsule or with complete success on delivery then even with this anomaly they're arguably no worse off than any of the previous space programs were, as far as reliability and safety goes.

Re:It was a good launch

[Electricity Likes Me]

Obviously SpaceX wants to achieve man-rating so that they can launch and return personnel in addition to the cargo runs they're currently beginning. I'm curious as to how this moderate malfunction will impact the rest of the program.

Bearing in mind, of course, the deaths of Chaffee, Grissom, and White in the Apollo 1 accident, the launch-time engine failure and later unrelated catastrophic failure for Apollo 13, the Challenger disaster, and the Columbia disaster, it's difficult to call SpaceX's anomaly as being any worse than those. If SpaceX manages a series of cargo deliveries without any loss of the capsule or with complete success on delivery then even with this anomaly they're arguably no worse off than any of the previous space programs were, as far as reliability and safety goes.

The important thing is whether they can successfully determine what actually happened, and why it happened (i.e. replicate the malfunction on a test bed engine). This was the thing Feynman was most critical of NASA for post-Challenger - that the whole disaster was caused by this faulty assumption about engineering risks on the O-Ring seals (i.e. the seals were getting eroded by exhaust during launch, but the question posed was "is this dangerous" not "why is this happening" - the former being foolish since the system was not designed to cope with this, and it's true cause was unknown).

It's a triumph that the launch still succeeded, but having averted an unforeseen consequence the only safe thing to do is make sure it's both forseen and mitigated in the future.

Re:It was a good launch

[cwebster]

A landing you can walk away from is a good landing... A landing when you can re-use the airplane is a great landing.

Re:It was a good launch

[TWX]

Very true, especially in the infancy of SpaceX's program. I do hope that they figure out why the engine failed, and hopefully their records on its manufacture and testing prior to its use will contribute toward answering that.

I'll have to ask my wife about it- she actually is a rocket scientist, albeit one that deals with solid rockets, not liquid, but I'd expect that the post-failure analysis would follow the same kinds of procedures.

Re:It was a good launch

[cplusplus]

The Ars Technica article states that Apollo missions had the same protections against engine failure, and that two of the Apollo missions actually suffered engine losses and still completed the mission. So, maybe there's precedent?

Re:It was a good launch

[CNTOAGN]

But what if the cost to fix the failure is deemed to high? It is an acceptable engineering practice to just plan on something going wrong x% of the time. Now if 1/9 is the maximum failure rate, and you can still get to orbit (meaning you design in the possibility of an engine exploding - can you imagine!), and the probability of 2/9 is astronomical, is something that is "forseen" have to be mitigated? Now granted, I hope the engine failure is truly something anomalous, given that even the smallest fracture can cause problems, and you have to test the engine at least once before use...

Will space travel ever enter the "good enough" phase of manufacturing? Being an A.E. I applaud the design of the falcon engine system. Just like most large aircraft can land with 1 out of 4 engines being functional, a system that can take a full system failure on one of its parts and still perform is quality engineering.

Re:It was a good launch

[TWX]

Others have covered the demonstrated failure rate being 2/27 or 1/18, depending on the type of mission. If we're talking about missions that reached ISS, we're at 1/18. I'd much rather see reliability rates in the 99+%, but even that's one failure in twelve launches to exceed 99% reliability in groups of nine.

Re:It was a good launch

[Anonymous Coward]

And as an airline passenger, would you share the pilots' opinion?

As a future space traveler, are you okay with exploding engines being "normal"?

As the company that produces and operates the spacecraft, any mission that you can complete and make a profit from is considered "good". Even if the whole fucking spaceship explodes that one time, but you still have a contract worth billions to keep flying.

Honest people recognize any failure as a problem. The backup system worked? Good. Doesn't change the exploding bit.

Re:It was a good launch

[tru3ntropy]

A landing you can walk away from is a good landing...A landing you can not walk away from is a crash.

Re:It was a good launch

[Narcocide]

Aeryn: Insane?
John: Since birth
Aeryn: Suicidal?
John: Test pilot

- Farscape (Self Inflicted Wounds, Part 1: Could'a, Would'a, Should'a)

Re:It was a good launch

[Cassini2]

Surprisingly, if failure is measured in terms of human deaths, fairly high failure rates are tolerable in many branches of engineering. It was assumed that about 5 people would die in the construction of a tall sky scraper. Now, with massive changes in safety, it is possible to build a sky scraper with no deaths. However, injuries still happen.

Similarly, mining regularly kills people. They have reduced their deaths per year from several thousand (1907) to averaging 6/year (2001-2005). See government records for details.

Manufacturing regularly hurts people, with occasional fatal accidents. Same with forestry.

Space travel is relatively safe compared to some of the shit jobs out there, particularly in places with lax safety records, like China. It helps that the average astronaut trainee doesn't actually make it into space.

Re:It was a good launch

[dbIII]

the seals were getting eroded by exhaust during launch

No it was a known glass transition temperature problem - the o-rings were not safe to use below a known temperature. It's the sort of problem where you can soak a squeaky rubber toy in liquid nitrogen for a while, then pull it out and shatter it with a hammer.

Re:It was a good launch

[Anonymous Coward]

...An automated landing where you can sleep through flight and landing is a dreamy landing... An auto-landing while you're re-upping a membership to the mile-high club is a fucked landing... A landing you controlled from the ground with no risk of dieing is the liveliest landing... A remote control landing where you only risk getting caught wankin' is the loneliest landing.

Re:It was a good launch

[uvajed_ekil]

Yep, you can't have all the answers until you know the questions. Components of the lift vehicle may have failed, but the failsafes performed as designed and the mission was completed successfully and on schedule. The redundancies and backups are built in as a function of the design, and may not even be called into action most of the time. All in all, this is proof that the system works, and I can not wait to see more launches. This was a perfect result and demonstrates a functional system that is good and will get even better.

If you took a team with an average age of 23 to the World Series or World Cup finals, you wouldn't complain if they only won 3-2.

Re:It was a good launch

[Armakuni]

The O-rings were being eroded by exhaust during launch because the rubber got too cold to seal properly. So you're both right.

Re:It was a good launch

[TheLink]

Space travel is relatively safe compared to some of the shit jobs out there, particularly in places with lax safety records, like China.

One of the most dangerous jobs is President of the USA. About 10% have died due to job-related issues. And it does not appear that the job has become much safer over the years.

Re:It was a good launch

[Anonymous Coward]

Yes. Spacex can not patemt it.

Re:It was a good launch

[scharkalvin]

The Saturn V rocket was certainly "man rated" yet it lost an engine during launch on TWO of the moon missions without aborting the flight. It's a NON-ISSUE since the possibility was designed into the rocket.

Redudant and not TBTF?

[Anonymous Coward]

Almost looks like a private company that doesn't depend on the government to bail them out. Something is wrong here.

Statement from SpaceX

[jkflying]

Approximately one minute and 19 seconds into last night’s launch, the Falcon 9 rocket detected an anomaly on one first stage engine. Initial data suggests that one of the rocket’s nine Merlin engines, Engine 1, lost pressure suddenly and an engine shutdown command was issued immediately. We know the engine did not explode, because we continued to receive data from it. Our review indicates that the fairing that protects the engine from aerodynamic loads ruptured due to the engine pressure release, and that none of Falcon 9’s other eight engines were impacted by this event.

As designed, the flight computer then recomputed a new ascent profile in real time to ensure Dragon’s entry into orbit for subsequent rendezvous and berthing with the ISS. This was achieved, and there was no effect on Dragon or the cargo resupply mission.

Falcon 9 did exactly what it was designed to do. Like the Saturn V, which experienced engine loss on two flights, Falcon 9 is designed to handle an engine out situation and still complete its mission.

Re:Statement from SpaceX

[EvanED]

none of Falcon 9â(TM)s other eight engines were impacted by this event.

God I hate this wording.

Don't use "impact" when you mean to say "affected", as I suspect they mean here, especially when the sentence could (if slightly tortuously) be read as "none of Falcon 9's other eight engines were hit [impacted] by debris from the fairing."

[I know that's not you, jkflying, I'm just ranting.]

Re:Statement from SpaceX

[tsotha]

Actually the other engines can definitely be impacted in a catastrophic failure.

Re:Statement from SpaceX

[EvanED]

That's, uh, kind of my point. If it was in a context where it was completely clear that "impact" meant "affect", it would merely be annoying; the fact that it could conceivably actually mean "impact" in this case is what makes me want to hit the author.

Re: Looks like we've had our glitch for this missi

[Maximum Prophet]

Looks like we've had our glitch for this mission

We've been "pre-disastered". http://www.imdb.com/title/tt0084917/

I am curious.

[Githaron]

How many of those nine engines can fail before the system cannot compensate?

Re:I am curious.

[manoweb]

I guess it depends on "where" (when?) they fail. In fact, at some point two engines are shut down to avoid too much g - probably at that point three failing engines could still be OK?

Re:I am curious.

[Anonymous Coward]

According to the article, just one. Protection against more than one would be likely a waste of mass...something catastrophic enough to take out two engines isn't likely to stop there.

Re:I am curious.

[goodmanj]

For the first stage, one at launch, two later on. From a strict physics perspective, you could probably have three or four out in the last few seconds of the burn, but I don't know if their software is that clever. The second stage has only one engine.

Re:I am curious.

[Anonymous Coward]

If the engines cannot be restarted in flight,the moment that the two engines shut down would be the time where a flight would be impacted. At that point, any engine loss that reduces thrust to the point where it isn't high enough to put the flight into orbit would be that impact (that is probably just one engine). You could probably lose an engine after the 2 engine shut down and continue to orbit (though that orbit will not be the planned orbit) through an extended burn of the remaining engines. The loss of a second engine however would probably cause of LOV.

If the engines can be restarted, then that changes what I said above. It would probably have been much better if the engines were designed to throttle from this perspective, but that would have increased development costs significantly as that makes for a far more complex engine design. When people ask how Musk was able to design a rocket for such a low cost, well that is how, design decisions like that which make for a much simpler design. (and no, I am NOT making a judgement on it. That is the point of engineering, you make compromises to meet the requirements within the desired budget).

Re:Fist Post!

[TWX]

Shut up, Fruitloops...

9 engines. All together now!

[Fuzzums]

9 engines of LOX on the rocket, 9 engines of LOX
drop one down, blow it around
8 engines of LOX on the rocket....

"Anomaly?"

[Vintermann]

I've been playing too much SpaceChem...

Dear SpaceX, Thanks For The Offer

[Anonymous Coward]

However, I'll launch my cargo to the ISS with A. P. Korolev RSC Energia, more reliable company.

Yours In Akademgorodok,
Kilogre Trout, Scientist

Re:Dear SpaceX, Thanks For The Offer

[Anonymous Coward]

We can copy :)
http://www.dailymail.co.uk/news/article-2083556/Meet-girl-blogger-sneaked-inside-Russian-missile-factory--security.html

We don't have this situation
http://en.wikipedia.org/wiki/Buran_programme#Buran_hangar_collapse

Re:Dear SpaceX, Thanks For The Offer

[VIPERsssss]

And don't ride in anything with a Capissen 38 engine, they fall right out of the sky.

Re:Dear SpaceX, Thanks For The Offer

[Anonymous Coward]

Gotta love that N1. With 30 rockets in the first stage, it was designed redundantly so that even with four engines out, it would still be able to make the biggest explosion in the history of spaceflight. Fuckin' russkies, ain't nobody better at blowin' shit up.

Re:Dear SpaceX, Thanks For The Offer

[Teancum]

The problem the the N1 is that it has a 0-4 record in terms of successful missions, including a major explosion on the launch pad that killed several hundred technicians. It was an amazing rocket, and it is too bad that Sergei Korolev was unable to stay alive long enough to get it working correctly.... but it also never was able to deliver on its promises either.

Re:Fist Post!

[JustOK]

There was a big bang, in theory.

Transparency ?

[m0s3m8n]

Did anyone here a call of engine cut-off in the NASA TV feed? I did not. Or a call for a longer burn? Seems the SpaceX team would have made those calls. Of course, they could have on private channels. Seems NASA was more transparent. Also, when I fly I like my pilots to be well dressed and professional. The SpaceX team did not. Maybe that is the SpaceX culture, but I am an old fart and I prefer a much more orderly look.

Re:Transparency ?

[Anonymous Coward]

Did anyone here a call of engine cut-off in the NASA TV feed? I did not. Or a call for a longer burn? Seems the SpaceX team would have made those calls. Of course, they could have on private channels. Seems NASA was more transparent.

Also, when I fly I like my pilots to be well dressed and professional. The SpaceX team did not. Maybe that is the SpaceX culture, but I am an old fart and I prefer a much more orderly look.

I understand where your coming from. As a former USAF airman I like sharp uniforms and haircuts also but in the end I don't want that for space flight. I want it so safe and routine that its just a normal blue jean, blue collar affair. That would indicate that we are really getting somewhere and I may be able to afford a ride.

Re:Transparency ?

[rickb928]

Time to let go of the white shirt/thin tie/pocket protector/black rimmed glasses look. T-shirts are the new uniform. Hair length is not a factor.

I know, I hate it too, but we are not far from everyone on the launch team Skyping in and being avatars on a plasma screen in front of the media videoconferencing system.

Re:Transparency ?

[goodmanj]

I missed the launch, and I haven't been able to find a recorded feed: if anyone has a link I'd love to hear the flight loop.

BUT, the mission control chatter you hear on a SpaceX launch is almost entirely people assuring themselves that the rocket is OK. They're not *controlling* much of anything: it's all in the hands of the flight computer, which decides things like "shut down this engine and recompute a launch profile for the remaining 8 engines" on its own, in real time. There's no time for humans to make a decision on this sort of thing: the decisions were made when programming the software, years ago.

I don't think they're hiding anything from the public, but what surprises me is that they seem not to have even *noticed* right away.

As for "well dressed and professional", even *NASA* doesn't play by your old fart rules any more. (Your words not mine...) http://www.businessinsider.com/bobak-ferdowsi-nasa-curiosity-landing-mars-mohawk2012-8

Re:Transparency ?

[Carnildo]

Did anyone here a call of engine cut-off in the NASA TV feed? I did not. Or a call for a longer burn? Seems the SpaceX team would have made those calls.

The decision to shut down engine #1 and the decision to adjust the other engines' burns to compensate were made automatically by the flight-control computer onboard the rocket. There's no need for the ground team to make the decisions, and no need for the computer to make voice announcements about them.

(Obligatory car analogy: it would be like having your car's ECU call your mechanic to announce that it's adjusted the spark timing to compensate for driver error.)

Re:Transparency ?

[m0s3m8n]

Your points are well taken, but in reviewing the NASA feed, the voice-over clearly stated that "all nine Merlin engines ... continue to burn ..." after 2 minutes. I believe this was a NASA voice-over, so that may be where the discrepancy happened. As for your analogy, I agree, but given today's techno-crap most cars are coming with, it would not surprise me if this does not happen in the near future, say for low breake fluid or cylinder misses.

Re:Transparency ?

[m0s3m8n]

I was not trying to say they would have had to do any manual intervention, and I would fully exept them to NOT have to, just like what happened last night. But as you mentioned, it did not appear like they noticed. Anyhow, I am glad the SpaceX engineering effort paid of. Good job.

Re:Transparency ?

[Anonymous Coward]

I watched the videos last night. A couple times during the post-launch press conferences, a reporter asked about the burn seeming a bit long. I don't remember whether a reporter or the SpaceX President raised the possibility of an engine failure, but the latter confirmed that that would explain a longer burn. At that point it was pretty clear that she didn't know whether either had actually happened.

As another responder noted, the burn adjustment was automatic and did not require any human action.

Re:Transparency ?

[mark99]

I don't care how they dress. I thought the "Mohawk guy" on the Curiosity landing was pretty cool. So do most others I believe.

Re:Transparency ?

[TooMuchToDo]

Well dressed and professional? Please catch up with the times. How you dress has nothing to do with your job performance.

Note: The Mars Curiosity Flight Director dyes his hair red and sports a mohawk.

http://www.reidwalley.com/wp-content/uploads/bobak-flight-director-mars.jpg

Re:Transparency ?

[wisnoskij]

So what is the point of even having communications then, if you have significant problems that are not even mentioned, while everyone continues to spout "everything is nominal".

Re:Transparency ?

[kwoff]

Did anyone here a call of engine cut-off in the NASA TV feed? .... Also, when I fly I like my pilots to be well dressed and professional.

I understand where your coming from. As a former USAF airman I like sharp uniforms and haircuts

These fashion-obsessed, grammatically-challenged posts could bee seen as arguments four SpaceX....

Re:Transparency ?

[osu-neko]

They didn't have any significant problems. They had an anomaly, but to call it a problem (much less a significant one) is to engage in exaggeration. The system dealt with the anomaly perfectly fine, as it was designed to do all along. If it had failed to do so, then it would be fair to say there was a problem.

Re:Transparency ?

[Guspaz]

The entire launch is completely automated from T-10:00, with no human intervention. After that, the only human interaction that might occur would be to force an abort. While it's odd that they didn't remark about the issue (since it would definitely have been obvious from the telemetry), they would not have *called for* engine cut-off or a longer burn, those were automated decisions made by the on-board computer.

Re:Transparency ?

[wisnoskij]

One of the engines failed, where the engines are pretty much the only thing doing anything directly.
This is like if you were driving around with a trailer and your hitch broke off, sure the chains that are attached between the truck and the trailer are still attached (aka the redundancy worked), but something serious and problematic happened.

When one of the engines fails on a plan (redundant or otherwise) the ground crew sure as hell hears about it, because not only is your redundancy gone, but something that should not of failed has failed and it was one of the major parts of the craft. And if something else goes wrong and your plans change, you need to know that you have one less engine then you should have.

Re:Transparency ?

[Teancum]

I was listening to the SpaceX feed when right around MECO (main engine cut-off) one of the SpaceX guys talked about a major alarm that sounded and asked the senior guys or flight director (this was off camera but on the loop audio feed) for further instructions. I can only presume this was an alarm indicating that the #1 engine shut down prematurely.

I did wonder right then and there if something "oops" had gone wrong.

Re:Transparency ?

[Nethemas the Great]

More orderly? You mean like this NASA guy?

Re:Transparency ?

[Nethemas the Great]

In this case the "car" analogy doesn't work. You might be able to get away with a tractor-trailer tire analogy where one tire on a dually blows but that's probably as close as you can get. The Falcon 9 is designed to complete successfully with multiple engine-outs. Late in first-stage flight they actually shut two of them down as part of normal operations to keep acceleration at 5Gs. You cannot however, drag your trailer around by the so-called "safety" chains let alone get to your destination that way.

Re:Transparency ?

[MoaDweeb]

Hey, if exploring the solar system a la Gattaca can be done in Armani suits then going into orbit could at least involve a shave and haircut. http://en.wikipedia.org/wiki/Gattaca

Fantastic Failure Design!

[Tim12s]

This is a fantastic launch and goes to show the safety design.

Dont be too foolish to assume, however, that NASA doesnt also have such designs or such safety mechanisms. Just because their launch has media hype does not discredit NASA.

Great engineering.

Saturn V engine loss?

[Anonymous Coward]

"Like the Saturn V, which experienced engine loss on two flights,"

News to me. Details anyone?

Re:Saturn V engine loss?

[0123456]

News to me. Details anyone?

Apollo 6 lost two engines and, AFAIR, suffered partial breakup of the SLA panels covering the lunar module due to pogo.
Apollo 13 lost one engine, which was fortunate because pogo had grown so bad that the Saturn V was on the verge of structural failure. If the engine hadn't failed, they'd have been parachuting back to Earth soon after.

Re:Saturn V engine loss?

[tp1024]

Parachuting back to earth would have been *a lot* more comfortable than what they ended up doing.

Re:Saturn V engine loss?

[goodmanj]

Apollo 6 (unmanned test, uncontrolled pogo oscillation during first stage, multiple engine failures on 2nd)
http://en.wikipedia.org/wiki/Apollo_6

Apollo 13 (manned launch, pogo oscillations again, shutdown of center first-stage engine.)
http://en.wikipedia.org/wiki/Apollo_13#Launch_incident

Shameless plug

[wonkey_monkey]

1. The Doctor

Doctor who?

A statistical analysis:

[mosb1000]

They've launched 4 Falcon 9 rockets. One engine has failed, so that's an observed failure rate of 1/36 or about 3%. The means the odds of 0 or 1 engine failing (a successful launch) is 97.6% and the odds of more than one failing is 2.4% assuming the currently observed rate is representative of the actual rate. 2.4% would be an excellent failure rate for any rocket launch system. In fact, no one has achieved a failure rate that low. And bear in mind this rate includes 3 experimental launches and only one production launch. Of course, a launch failure can be brought about by more than just engine failures, so 2.4% is really a minimum and other factors which haven't yet manifested themselves would add to it.

Space X is saying that this is probably a failure in the aerodynamic structure of the rocket, not the rocket engine itself. If that's the case, the above statistical analysis is invalid because it assumes no interdependency in engine failures. A structural failure could lead to more than one engine failing. It would also be problematic in assessing the future failure rate because the engine configuration is going to change in their 1.1 version. The outer engines will be circularly arranged in future versions while in current versions they're arranged in a square.

Re:A statistical analysis:

[Jubedgy]

And Spacex has had non-engine flight failures. One of which was caused by poor separation timing: residual thrust in the first stage after stage separation caused it to impact the second stage prior to ignition. Oops! What is this, rocket science?!

Re:A statistical analysis:

[beltsbear]

That calculation of failure rates is way off. They have had 1 in 4 rockets with a defective engine, 1 in 16 could on average have TWO defective engines. You can not take the failure rate of a single engine and work that way. They have 9 engines in the first stage of each rocket and that multiplies the chances of failure. We also do not know if they just got lucky that the explosion in the engine as it did not take out any other engines. Exploding engines can take out other engines as well.

Re:A statistical analysis:

[mosb1000]

They have had 1 in 4 rockets with a defective engine, 1 in 16 could on average have TWO defective engines.

I'm not sure if you're serious or not, but I got a good laugh out of that one. Please elaborate on your calculation technique if you'd like me to point out what's wrong with it.

You can not take the failure rate of a single engine and work that way.

That may or may not be true. You'd need to see at least one multi-engine failure before you can reasonably conclude that one engine can cause another to fail. Once they've done about 100 launches, you can see if single engine failures occur about 20% of the time and double engine failures occur 2% of the time. If that's the ratio, you can reasonably assume engine failures are not related to each other. As far as explosions go, they do have firewalls in place to prevent an explosion in one engine from cascading to other engines. Each engine operates independently, so there's no reason to assume that a failure in one engine will cause failures in others. At this point, it looks like a failure in one engine will not cause failures in the others, since only a single engine failed during this launch.

They have 9 engines in the first stage of each rocket and that multiplies the chances of failure.

Nope, if they had a single engine their failure rate would be about 2.8%. With 9 engines, and the ability to operate with one engine out, their failure rate would be 2.4%. So the failure rate is actually reduced.

Re:A statistical analysis:

[0123456]

As far as we know right now the engine didn't explode, and they have some blast shields to try to protect the other engines if it does. But I believe you're right about the failure rate calculations, you don't need a very high failure rate to have a reasonable chance to lose two engines out of ten.

On the other hand, I believe there's only one more flight using these rev C engines and the rev D will be flying soon. So it's quite possible that whatever caused this engine to fail won't affect the new ones anyway.

Re:A statistical analysis:

[Algae_94]

They had 1 out of 36 engines that have failed. That's a 2.78% chance of an engine failing. The odds of a launch having no failures at all is, 77.60%, the odds of having one and only one failure is, 19.96%. A successfull launch as defined by one or no engine failures has a 97.56% chance.

This is a risk of 2 or more engine failures of 2.44%, not 6.25% like you say (1 in 16). This is all assuming future failures follow the same rate as currently seen.

Re:A statistical analysis:

[Anonymous Coward]

From a statistics standpoint, you can't just use the, we only had one engine failure in 4 launches for two reasons:

1) the engines are used in clusters of 9 in this application, and you can't treat each engine separately from a failure mode analysis viewpoint

2) the engines don't all run for the same length of time. Because 2 engines are shut down early in a nominal mission, you need to start measuring the failure rates based on engine burn duration, not as an absolute.

Re:A statistical analysis:

[crunchygranola]

...The means the odds of 0 or 1 engine failing (a successful launch) is 97.6% and the odds of more than one failing is 2.4% assuming the currently observed rate is representative of the actual rate. 2.4% would be an excellent failure rate for any rocket launch system. In fact, no one has achieved a failure rate that low....

There are vehicles that have matched or beaten this rate. The Delta 2 (retired) achieved 149 out of 151 (99%). The currently active Soyuz-U has achieved a failure rate indistinguishable from this (741 successes out of 761, 97.4%). There are other vehicles that claim 100%, but have launched too few to be able to claim this rate. One factor to consider is that launch systems often mature and have a long series on unbroken successes after having some failures early on: http://www.spacelaunchreport.com/log2012.html

Re:A statistical analysis:

[GerryHattrick]

Missed a step? "They had 1 out of 36 engines that have failed... If that is fully representative of the risk of failure, ...That's a 2.78% chance of an engine failing." Might feel it's too small a sample to base a safety case.

Re:A statistical analysis:

[Anonymous Coward]

Just in terms of the Merlin engines, 45 have flown: 5 Falcon 1 first stages, 4x9 on Falcon 9 first stages, and 4x1 on Falcon upper stages. One engine failure in 45 is pretty good in this biz. And the upside of a non-mission-lethal engine failure where the telemetry stays on is that you learn things that can be used to improve the design.

Re:A statistical analysis:

[Algae_94]

Yes, it is a very small sample set. That is why I ended with, "This is all assuming future failures follow the same rate as currently seen". It is very possible that the failure rate is actually higher. It could also be lower.

Looks like a decoke job is needed ...

[Anonymous Coward]

try using decent fuel and maybe a can of BG44K - that should keep those babies running sweet.

Re:Fist Post!

[JustOK]

All the bare-naked ladies said that.

Makes me like it even more

[HangingChad]

It can lose an engine and still make it into orbit! Seriously, how amazing is that?

I supposed they could go with fewer engines, but if they lose one the consequences are greater.

Now they have proof the fail-over systems work. Don't mess with success.

Re:Makes me like it even more

[v1]

I'd bet it can technically cope with the loss of more than one engine, but may not have the thrust required to get to the necessary orbit. I don't know to what extent they can lengthen the burns to compensate for lost thrust earlier in the ascent.

I was also wondering what happens if there's a more catastrophic failure in the center engine. (being 9 engines in a 3x3 group) You'd think a failure there could cause problems for the surrounding engines moreso than if one of the outer engines went. The way the fairing shed, what would happen if that fairing sprayed out and damaged the fairing on several other engines? I wonder if they handle that engine any differently? Higher quality control for example? The odds of getting orbit if you lose one outer engine is probably different than if you lose the middle one. But it wouldn't require so much adjustment for course, so maybe the two factors balance out? And makes me wonder what sort of armor they have around the engines to protect them from each other in such an event?

Other thing of course is, if you lose two engines adjacent to each other. The way the fairing shed, and in the case of an explosion, there's significant risk of damage to adjacent engines. That may simply cause an imbalance that's difficult or impossible to manage while still making assigned orbit. (may have to dial down the opposing engines so far to balance the thrust, that you don't have sufficient total thrust to do what you need to?)

wow

[Tastecicles]

that was a bit of a bang... lucky the systems were in place to prevent it turning into a disaster...

Also: I've seen comments on the mechanics of dealing with the ejecta. It's simple: when an engine fairing blows, it's no longer travelling at the same speed and direction as the rest of the vehicle. It might explode outwards, but it is, from that point, no longer accelerating upwards. The rest of the vehicle carries on accelerating away from the point of explosion and the wreckage becomes a passenger of Newton. Similarly with the Challenger: you may have noticed from the video of that event that the SRBs kept on going, intact until they splashed down. This is because they were travelling at such a speed and *still accelerating* that the exploding fuel tank and vehicle they were bolted to stopped accelerating and they quickly left the wreckage behind - physics once again provides a simple answer as to why the SRBs didn't turn into giant sticks of dynamite.

ought to be obligatory

[wes33]

"Did the primary buffer panel just fall off my gorram ship for no apparent reason?!"

Learning from the past

[Paul Fernhout]

Why would you not want to help a next generation to build on the hard-won successes of the previous? As is said here:
    http://en.wikipedia.org/wiki/Social_Credit
"Douglas disagreed with classical economists who divided the factors of production into only land, labour and capital. While Douglas did not deny these factors in production, he believed the "cultural inheritance of society" was the primary factor. Cultural inheritance is defined as the knowledge, technique and processes that have been handed down to us incrementally from the origins of civilization. Consequently, mankind does not have to keep "reinventing the wheel". "We are merely the administrators of that cultural inheritance, and to that extent the cultural inheritance is the property of all of us, without exception.""

Re:Learning from the past

[Anonymous Coward]

It's not like the dudes scrapbooks are secret information that wasn't released. Anything he scrapbooked is known of to the people working on these issues.

Re:Learning from the past

[Paul Fernhout]

So much can get forgotten from one generation of engineers to another -- especially all the things that did not work. Even assuming all the information is publicly available, the effort spent collecting it, organizing it, and filtering it from a vast amount of other information at the time is potentially valuable.

Re:Learning from the past

[Raenex]

Maybe he doesn't really have them and is bullshitting. People do that a lot.

Re:Learning from the past

[Anonymous Coward]

Then what do you do when they're all in retirement homes, getting senile, and dying off?

Relevant xkcd comic: http://xkcd.com/893/

Neil Armstrong just died age 82, I bet a lot of the Apollo (and Soyuz, Salyut and Skylab etc.) ground personnel and engineers are getting well along in age too.

Re:Learning from the past

[rickb928]

I was 15 when Armstrong stepped off the LEM. I scrapbooked some of Mercury, all of Gemini, and Apollo. News clippings, magazine articles, notes.

IANARS. Sheesh, I'm not holding the keys to interplanetary glory, you sad miserable geese.

Re:Learning from the past

[Raenex]

That clears that up. You did come off as sounding technical and involved in the project.

Re:Learning from the past

[rickb928]

My brother did some work on 39 A and B, but in the Shuttle era. He's a master electrician, and did some PLC stuff, which I'm very proud of, cause when he asked me eons ago about those things, I told him to 'go for it'. He did.

Re:Learning from the past

[adri]

That would still be really nice to have online!

Re:Learning from the past

[rickb928]

Sure thing. when I decide how *I* get the page hits, I'll be posting glorious hi def scans of the yellowed newsprint and Time magazine clips, and respond to the takedown notices in my spare time.

Real soon now.

Re:Learning from the past

[Paul Fernhout]

"and respond to the takedown notices in my spare time."

That's certainly a good legal point, showing how far out society has regressed since the 1960s -- no only can't we put a human on the Moon anymore, but we can't even discuss it while including copies of forty year old documents (that should long ago have become public domain under any reasonable copyright regime).

Makes me think of:
http://en.wikipedia.org/wiki/Dark_Age_Ahead
"Using this and other examples, Jacobs argued that modern political and economic ideologies were in effect no different than those dominant in Western civilization's past Dark Ages, such as Middle Age Roman Catholicism. In both cases, she claimed, the dominant ideology prevented and discouraged people from finding rational and scientifically-verifiable explanations and solutions."

As Jane Jacobs says, a Dark Age is when a society has forgotten even that it used to know something. We seem to be getting there in spaceflight, a few recent small company proprietary successes aside, like SpaceX. In general, the USA has also made publicly discussing some aspects of rocketry and such illegal for military reasons.
http://www.exportlawblog.com/archives/439

Still, some people are trying to relearn things on a small scale:
http://www.smartplanet.com/photos/privately-funded-open-source-rocket-lifts-off-photos/6243520

My own, so far unsuccesful, steps in that direction, but others are succeeding in that idrection as part of an open manufacturing movement:
http://www.kurtz-fernhout.com/oscomak/

Bad calculation. The reality is much worse.

[Anonymous Coward]

If prob of success for an engine is 35 out of 36, then it's -> .972 (how did you get 97.6% ?). This *isn't* the prob of success of a *launch*. Prob of success of a launch is having 8 engines work (the 9th we don't care) -> .972 exp 8 -> .798 and this is terrible. Chance of a successful launch (having at least 8 engines work) is basically 80%. On average 1 out of 5 launches will end up in the drink.

Re:Bad calculation. The reality is much worse.

[mosb1000]

No, this is not a correct analysis. You have to break it up into all 512 possible outcomes and then calculate the probability for each. So one of the possibilities is that all engines will work, that has a probability of (35/36)^9 or 77.6%. There are 9 possible ways that one engine could fail. Each possibility has a probability of (1/36)^1*(35/36)^8 or 2.2%. If you multiply that by the 9 single engine failure possibilities you get a probability of 20.0% that exactly one engine will fail. So if a successful flight can have either no engines or one engine fail the probability is 77.6% + 20.0% = 97.6%. Does that make sense?

Re:Bad calculation. The reality is much worse.

[Chris Burke]

So if a successful flight can have either no engines or one engine fail the probability is 77.6% + 20.0% = 97.6%

SpaceX has said that they deliberately turn off 2 engines during flight, and a successful launch could therefore suffer 2 engine failures of this nature.

Re:Bad calculation. The reality is much worse.

[mosb1000]

If that's the case, you need to add the odds that exactly 2 engines will fail to the above calculation. There are 36 possible configurations where exactly two engines will fail, each has a probability of (1/36)^2*(35/36)^7: 36*(1/36)^2*(35/36)^7 = 2.3% so the overall probability of a successful flight would be 77.6% + 20.0% + 2.3% = 99.9% leaving a truly minuscule probability that you'd ever see a launch failure due to this problem, assuming that one engine failure will not cause failures in additional engines.

Re:Bad calculation. The reality is much worse.

[Chris Burke]

leaving a truly minuscule probability that you'd ever see a launch failure due to this problem, assuming that one engine failure will not cause failures in additional engines.

Which is probably not a good assumption, but I think we have some decent evidence that the correlation between failures of multiple engines is not extremely high.

Gotta say, I'm impressed. And the best part is that a tolerable failure like this one gives them the best chance to identify and fix it -- because one they get more data from a rocket that continued to exist than catastrophically fail and two it won't impact their business model much -- and thus further reduce the risk in the future.

Re:Bad calculation. The reality is much worse.

[mosb1000]

Using 9 smaller engines allowed them to use the Falcon 1 as a testbed so that they could work the kinks out on a smaller, less expensive rocket then scale up to a much larger rocket without making a lot of changes. It seems to have worked, since they haven't had any total failures during the Falcon 9's development (thereby saving $$$).

Re:Bad calculation. The reality is much worse.

[Anonymous Coward]

SpaceX has said that they deliberately turn off 2 engines during flight, and a successful launch could therefore suffer 2 engine failures of this nature.

It's not as simple as that.

It's common for rockets to reduce thrust as they gain altitude. Fuel mass is being thrown out the back of the vehicle, so by Newton's Law (F=ma, or a=F/m), acceleration increases throughout the flight if thrust is held constant. But most payloads, even non-living ones, can't take arbitrarily high G loads. Same goes for the rocket structure itself. There's also buffeting and load on aerodynamic surfaces, before the rocket reaches altitudes where the atmosphere is too thin for it to matter.

So: rockets need maximum thrust at takeoff and low altitudes, when they're moving slowly and must build up speed to get out of the atmosphere. Later on, they must reduce thrust as they approach maximum designed dynamic pressure limits (aka Max-Q) and/or G loads.

That's the reason why Falcon 9 shuts off 2 engines during flight -- it's to reduce thrust at Max-Q limits. They do actually need all 9 engines for normal performance before then. SpaceX claims a 1-engine loss is automatically compensated for by extending the total first stage burn time, but I'm skeptical that it would provide 100% of intended performance in all cases, especially for very early failures (e.g. right after liftoff).

(In fact, this launch failed to put one of its two payloads into its intended orbit. It's not yet clear whether that was a consequence of the failed engine, but it very well could be.)

Re:Bad calculation. The reality is much worse.

[Chris Burke]

It's not as simple as that... I'm skeptical that it would provide 100% of intended performance in all cases, especially for very early failures (e.g. right after liftoff)

Of course, I'm just going by SpaceX's statement that they could have sustained two engine failures "of this nature", which obviously includes it happening late in the boost near when they were going to be turning them off anyway thus the relevance of them mentioning that, versus on the pad.

(In fact, this launch failed to put one of its two payloads into its intended orbit. It's not yet clear whether that was a consequence of the failed engine, but it very well could be.)

It seems to be clear that it is. Due to the failed engine they had to alter the trajectory. Because the new trajectory was not able to be checked for safety wrt the ISS in time, they were not authorized for the planned second burn of the second stage, which still could have in theory delivered the Orbcomm satellite to the proper orbit.

So, the failure definitely affected the success of the mission, but not because of the rocket's capability to recover from the failure, just wise precautions. Being demonstrably able to finish the primary mission after that failure, and theoretically being able to handle two of this kind, is pretty impressive. Of course no failing engines will be the situation they strive for in the future. :)

I see. I agree with 97.6 % success rate.

[Anonymous Coward]

I see. I agree with 97.6 % success rate.

Prob all engines OK = (35/36) ^ 9 = (0.972222222) ^ 9 = 0.776
Prob exactly one engine fails = 9 * (1/36) ^ 1 * (35/36) ^ 8 = 9 * (0.027777778) * (0.972222222) ^ 8 = 0.200
Prob all engines OK or only one engine fails = 0.776 + 0.200 = 0.976
So 3 launches out of 100 will fail.

Thanks.

They need a Falcon-"11"....

[Anonymous Coward]

That way they can turn it up to "11". Nobody else has a rocket with an "11" position...