SpaceX's Falcon 9 Crashes Into Droneship (cbsnews.com)

SpaceX failed to successfully land its Falcon 9 on a drone ship at sea on Wednesday. Prior to today's crash, the company was able to conduct three successful experimental landing of its used rocket in a row. SpaceX founder Elon Musk noted that the booster rocket had a RUD (rapid unscheduled disassembly, he explained) on droneship. From a CBS News report: It was the California rocket company's fifth unsuccessful drone-ship landing after three straight successes, one in April and two in May. Including a successful landing at the Cape Canaveral Air Force Station last December, SpaceX's recovery record now stands at four successes in nine attempts. But the landing attempt was a strictly secondary objective. The mission's primary goal, the launch of two powerful all-electric communications satellites, was a complete success and regardless of the loss of the first stage, company engineers expected to collect valuable data as they continue their push to make such landings routine.

Comments

RUD FUD

[ColdWetDog]

I like that....

This is still lots better than what NASA is doing. Stressing the technology. Doing new things.

Going ka boom. Everybody needs an earth shattering kaboom now and again. I just wish they'd have audio on the drone ship.

Re:RUD FUD

[ShanghaiBill]

This is still lots better than what NASA is doing. Stressing the technology. Doing new things.

NASA's funding depends on pleasing politicians. So they need to be overly cautious and avoid pushing tech till it breaks, even if we would learn more that way. SpaceX's investors have a longer attention span than voters. In may seem that caution is prudent, but excessive caution can be very expensive in terms of lost opportunities. So far, SpaceX has spent less than 2% of NASA's annual budget.

All Electric? Cool!

[BenJeremy]

...the launch of two powerful all-electric communications satellites

I'm glad we are finally getting past the era of internal combustion and the earlier coal-fired satellites!

Re:All Electric? Cool!

[Anonymous Coward]

Gotta push the memes while they're hot. Gluten free water. Asbestos free turkey. Non radioactive microwave oven.

Re:All Electric? Cool!

[Burdell]

The majority of satellites use chemical rockets for orbit changes and station keeping. When the relatively small amount of propellant is used up, so is the satellite (even if it is otherwise still functional). Using ion propulsion instead could increase the life of satellites, which reduces costs.

Re:All Electric? Cool!

[Anonymous Coward]

ion propulsion is NOT "all electric". Still need some particles to ionize.

Re:All Electric? Cool!

[ClayJar]

Also, chemical propellant is "heavy", meaning it takes much more mass to get an equivalent kick. If you want real words, the Isp (specific impulse) is lower for chemical propellant engines than for ion engines. With all electric satellites, you can carry much less propellant, meaning you can have a satellite of comparable capability in much less mass. In the case of these two satellites, the Boeing BSS-702SP platform they're built on means you can fit two on a "normal" GTO launch. That basically halves your launch costs.

The tradeoffs are that while all electric propulsion is very "fuel efficient", the thrust of ion engines is a very small fraction of that of the more conventional chemical propellant engines, so instead of taking days to settle in to your final orbit, it can take weeks of slow orbit raising. This is a "cost" that may or may not be worth the trade. Also, since the 702SP satellites are launched in pairs, a launch failure could take out two birds with one... rocket. To give a bit of insurance against this, Eutelsat and ABS chose to split two rockets. They'd each fly one satellite per launch, meaning they only risked one of their two each flight in case of a Very Bad Day.

Re:All Electric? Cool!

[Anonymous Coward]

Technically earlier satellites do in fact use internal combustion engines, since a rocket motor (including the chemical thrusters used for satellite manoeuvring) is classed as an internal combustion engine. Coal, I'm not so sure about as far as satellites are concerned. However hybrid rocket motors using coal as the solid fuel have been tested in the past. A quick search reveals for example this article, if you scroll down to "Pioneers", we have

"In Germany from 1937-1939, I.G. Farben ran tests using coal and gaseous NOX, which developed 10,000N for 120 sec. Hans Oberth also tested a LOX and tar-wood-saltpetre mixture.

The first US tests were conducted from 1938 to 1941 by the Californian Rocket Society using coal and GOX. In 1947, the Pacific Rocket Society tested wood and LOX motors.".

So not only coal but wood-powered rocket motors have existed.

Re:All Electric? Cool!

[suutar]

at a guess, difficulty getting more plutonium and fear of a launch accident spreading plutonium around.

Re:All Electric? Cool!

[Solandri]

I am for nuclear power, but RTGs are:

• Rare. The isotopes whose properties match the use criteria are mostly generated in breeder reactors or reactors specialized for generating medical isotopes, or as a byproduct of weapons grade plutonium production.
• Expensive. Due to protests over their use, any launch with a RTG aboard undergoes extra scrutiny and requires additional studies before approval. You also need to have extra security to protect the launch site and payload from protesters.
• Produce energy in the form of heat. This is good far from the sun where you need heat to keep your electronics from freezing. But closer to the sun you have the opposite problem, and you have to work hard to expel heat from the satellite. So closer to the sun, an energy source not based on heat is preferable.
• Dangerous. I don't mean they'll burn up on re-entry and spread plutonium all over the atmosphere. The canisters which contain the radioactive materials have demonstrated they will survive re-entry intact in the event of a launch mishap or satellite de-orbit. The problem is after they re-enter, they're a powerful radioactive source in a cannister lost in some random location where anyone could potentially find it. That is not a good combination. Responsible use of RTGs near the Earth means doing a controlled de-orbit of the satellite (not always possible) so RTG lands in the deep ocean, or conducting an expensive search and recovery operation afterwards to find the RTG before thieves do.

Save the RTGs for the deep-space missions. There's plenty of solar energy in Earth orbit to power satellites (solar flux is nearly 2x what it is on the Earth's surface without an atmosphere to scatter and absorb sunlight, and the high launch costs mean you can afford the expensive high-efficiency panels). Batteries (to power the satellite during the 45 minutes it's in the Earth's shadow) can operate for a decade or more, which is about the time you start thinking of replacing the satellite anyway due to its technology being outdated.

Re:All Electric? Cool!

[Immerman]

Who said there was (aside from reentry concerns)? But RTGs only provide electricity, you still need something to provide thrust.

Traditionally thrust has been supplied by internal-combustion chemical rocket engines, but electrically powered ion drives are starting to catch on - they still rely on consumable reaction mass, but accelerate it to much higher speeds than chemical rocket exhaust, and so can get far more delta-V from the same amount of reaction mass.

The other option is magnetic-drive, having the satellite actually push against the Earth's magnetic field rather than throwing away reaction mass. I'm not certain if such a thing has actually been tested, but as I understand it designs typically involve running a current through a long coaxial cable dangling from a satellite, so that the outer current interacts with the Earth like the coil in a motor, speeding or slowing its rotation around the Earth. You do end up replacing the reaction mass with probably greater cable-mass, but the cables are non-consumable so the satellite will be able to maintain its orbit for as long as sufficient electricity is available.

Re:All Electric? Cool!

[DerekLyons]

Also, chemical propellant is "heavy", meaning it takes much more mass to get an equivalent kick. If you want real words, the Isp (specific impulse) is lower for chemical propellant engines than for ion engines. With all electric satellites, you can carry much less propellant, meaning you can have a satellite of comparable capability in much less mass.

Ion propulsion is heavy too. While the ISP is very impressive - ISP isn't everything, except to armchair engineers. T/W matters too, and for electric T/W isn't all that impressive... and unlike chemical engines, there's very little benefit gained as fuel is exausted as the mass of the fuel is such a small fraction of total powerplant mass. There's a reason why electric propulsion has only found niche applications.
 

In the case of these two satellites, the Boeing BSS-702SP platform they're built on means you can fit two on a "normal" GTO launch. That basically halves your launch costs.

At the cost of requiring four to six months (as opposed to four to six days) for the satellite to reach it's station on orbit. (TANSTAAFL.) It's also worth noting that this is only possible because during orbital transfer, the communications systems that are the reason for the satellites existence are turned off - making their substantial power supply available for the electric engines.

Re:All Electric? Cool!

[dpilot]

My impression is that satellites have been using this as part of their attitude control for quite some time. More specifically, they have gyros that they use to change the attitude. Periodically the gyro gets near the limits of what they can do. When that happens, they reset the gyros back to a neutral setting, and offset that with a matching torque against the Earth's magnetic field so the attitude remains constant.

The gyros can move the satellite faster and more easily than the magnetic torquing system, so that's what's used for normal attitude control.

Re:All Electric? Cool!

[starless]

But it is electrically powered rather than by chemical reactions.
So I think it's still a pretty good description.

Re:All Electric? Cool!

[Bengie]

Got you beat. I saw "Gluten-free low-sodium table salt" at the store.

Re:All Electric? Cool!

[lars_stefan_axelsson]

Got you beat. I saw "Gluten-free low-sodium table salt" at the store.

Yes, but even the "low sodium" part is true as these table salts usually substitute potassium chloride for the more common sodium chloride. So they really are both "table salt" and low sodium.

That large concentrations of potassium aren't necessarily good for you either is another matter, but getting more is probably a good idea as most people don't get enough potassium compared to sodium.

Telemetry

[JamesPLynch]

Musk tweeted:
"Looks like thrust was low on 1 of 3 landing engines. High g landings v sensitive to all engines operating at max."
"Upgrades underway to enable rocket to compensate for a thrust shortfall on one of the three landing engines. Probably get there end of year."

Landing video froze at the last moment but it looked like a bulls-eye landing. There was flame climbing up the side of the stage. Telemetry should be helpful in making improvements.

Re:Telemetry

[bill_mcgonigle]

Does the engine design have that margin already?

FWIW, the Falcon 9 heavy will have nine of these engines. 8/9 seems easier than 2/3 (and of course 7/9 is easier on the eyes).

Re:Telemetry

[Anonymous Coward]

Falcon 9 has 9 of those engines. they only use 1 to 3 of them for landing depending on the launch profile, using all 9 of them would make the rocket go back up instead of landing (technically if they left 1 of them turned on long enough it would make the rocket go back up, part of what makes landing a falcon so challenging compared to the blue origin's rocket)
Falcon heavy will have 9 on each core, with 3 cores, total of 27 of engines, but each core will have to land independently. So for the landing, not much actually changes, other than two of them happening at the same time (and one slightly later if they try to recover the center core, probably only going to be feasible on very heavy launches to LEO)

Re:Telemetry

[cbhacking]

That's for single-engine landings, when they have more than a trivial amount of fuel left and can afford the time to land gently. That really only works for launches to low earth orbit (LEO).

Geosynchronous Transfer Orbit (GTO) or Super-Synchronous Orbit (SSO) launches are another matter entirely. Those use very nearly all the first stage's fuel, and go extremely fast. The rocket doesn't have enough fuel to "boost back" the way it does for LEO landings, so the droneship needs to be much further out to sea. More relevantly here, though, the rocket doesn't have enough fuel to make a (relatively) long minimum-thrust burn on one engine. Instead, it runs three engines (at an unknown throttle level, but possibly a fairly high one) for mere moments, to kill its velocity as quickly as possible (this exerts about 12G on the rocket, much more than it takes at any other part of the flight). This actually requires less fuel than the single-engine burn, because of gravity losses. The entire time the engine(s) are firing, a portion of their produced thrust is wasted countering gravity; a shorter burn means less time spent in the gravity-fighting range between terminal velocity and touchdown.

This launch was to SSO, and carrying two satellites at once to boot. The rocket was coming down extremely fast. Even if it wasn't running those three engines at max - and it may well have been doing so - there probably wasn't time to throttle other engines up in response to one engine underperforming. The entire maneuver is over in a few seconds, and at that kind of acceleration (12G!!) every fraction of a second counts.

Takeoffs More Important

[Bing Tsher E]

More important than a successful landing is a successful second takeoff of the recovered Falcon 9 stage. Without that this is just scrap metal recovery.

So we will need to wait and see.

Re:Takeoffs More Important

[LWATCDR]

Don't forget about turn around time.
That is going to be an issue. Will the second flight of the first stage be as reliable as the first flight and how long and how much to get to the first flight.
If you can reuse the stage but you have a good chance of it not working the second, third, ...... x time then is it worth it?

Rapid Unscheduled Disassembly = Leadership

[Anonymous Coward]

Mr. Musk "get's it". His engineering team is working on the edge of what can be done and failures are going to happen (they're landing a frigging rocket on a ship... backwards). He can either say "we failed" or he can say we had an "RUD". It means the same thing and everyone knows it but it deflects from the technical team somewhat and is gentle signal to the team that their heads aren't on the block (at least yet). It's a good way to lead. Just hope he never uses the world "fail"... because he does have that whole evil genius vibe going.

Re:Rapid Unscheduled Disassembly = Leadership

[ceoyoyo]

You need to attend some management seminars or something. Here's my effort:

"Upon reentry the first stage enjoyed a propulsive challenge. Our team leveraged this opportunity to widen the already commanding lead enjoyed by our best-in-class rentry vehicle. We look forward to offering our partners even more amazing solutions in the immediate future!"

Re:Rapid Unscheduled Disassembly = Leadership

[WheezyJoe]

What? No mention of maximizing shareholder value?

Re:Someone is playing Kerbal Space Program

[ray-auch]

RUD = "Rapid Unplanned Disassembly" has been around a _lot_ longer than ksp.

See google books for one example from 1991, but it goes back much further than that.

Pushing the envelope

[sjbe]

NASA's funding depends on pleasing politicians. So they need to be overly cautious and avoid pushing tech till it breaks, even if we would learn more that way.

I think that philosophy is just timidity at its worst. NASA could go and push the envelope and blow some stuff up. They've done it before. The problem is that they lack an administrator with the cojones to stand in front of congress and explain why blowing up the occasional rocket is a good thing.

SpaceX's investors have a longer attention span than voters.

Voters don't have much say in the funding of NASA. In fact very few of them really give much of a shit about NASA at all and NASA hasn't given them much of a reason to give a shit. SpaceX has a CEO who is also a substantial shareholder (reportedly at least 25%) and controls the company which has a LOT to do with the laser focus and long term outlook.

Re:Someone is playing Kerbal Space Program

[Applehu Akbar]

"Also lithobreaking is used as a term for crashing."

No, that refers to a type of prison labor. You mean lithobraking.

Re:why no upper body capture loop?

[Immerman]

I imagine adding a ~60m tall gantry with support arm, sturdy enough to withstand repeated rocket detonations at point-blank range (because accidents will still happen), would be a little expensive on what's currently basically a big floating target to shoot massive bullets at. Plus you then have to avoid it during the landing, and have the support arm get in place, adapting to an uncertain rocket position, within a second or so of touchdown before it's too late to do any good.

Then, assuming you solve those problems, you now have a "safety net" that would be financially foolish to not use every time, essentially killing any further advancement in unaided landing stability. Which is counterproductive to their long-term goal of developing the technology to land people on Mars, were there won't be any "safety nets" available. Because *that* is what Musk has repeatedly said is motivating him - launching payloads into orbit is just an economically viable means to that end.

Besides, even here on Earth, being able to land anywhere flat and solid offers far more long-term options than needing a landing gantry.

Re:Someone is playing Kerbal Space Program

[camperdave]

I'm sure lots of things break when a rocket reaches the lithosphere.

SpaceX customers

[sjbe]

SpaceX is doing many of these things under contract to NASA *using NASA funding*

SpaceX has had six launches in 2016 so far and only one of them had any relationship to NASA as far as I can tell (a supply mission to the ISS). The rest were private launch contracts. NASA is a customer of SpaceX and has helped them a lot but if you look at the launches SpaceX has scheduled, relatively few of them are NASA funded.

Re:SpaceX customers

[jpapon]

NASA has invested *heavily* in the development of the Falcon 9. From Wikipedia:

As of May 2012, SpaceX had operated on total funding of approximately $1 billion in its first ten years of operation. Of this, private equity provided about $200M, with Musk investing approximately $100M and other investors having put in about $100M (Founders Fund, Draper Fisher Jurvetson, ...).[54] The remainder has come from progress payments on long-term launch contracts and development contracts. As of April 2012, NASA had put in about $400–500M of this amount, with most of that as progress payments on launch contracts.[55]

NASA does take major risks. One of those risks was paying for SpaceX launches long before SpaceX had a track record.

Re:SpaceX customers

[nitehawk214]

NASA isn't stupid. They know if a rocket with their name on the side explodes, politicians will go apeshit and immediately cut funding. If a SpaceX or Orbital ATK rocket explodes (which both had a NASA ISS payload explode), well that the cost of being on the forefront.

And it is the cost of pushing the envelope, so NASA does what it can to get these missions flying on American hardware from American launch sites. Politicians be damned.

Re:SpaceX customers

[tsotha]

That's an odd use of the word "invested". Typically when you purchase something from a company you don't consider yourself an investor.

The mission was successful

[MrJones]

Falcon 9 Landen, then exploded. That article is too negative. SpaceX managed to deploy 2 satellite into 2 different orbits, successfully!!!!

Barbed feet

[Traf-O-Data-Hater]

An upper capture loop sounds worthwhile, but I have been puzzled as to why the deck of the droneship is not a mesh grid, and the landing feet don't have semi flexible barbs.

Consider the facts

[Skythe]

I'm sure I am preaching to the crowd here, but the crash should be considered in light of the following facts:
- SpaceX customers still pay for the entire rocket, there is no discount applied yet
- All other competing rockets do not have this capability and burn up on re-entry
- Every landing attempt provides new and unique data that can be used for continuous improvement
- The primary mission (what they are being paid for) was still accomplished