Could SpaceX Rocket Technology Put Lives At Risk? (chicagotribune.com)

In preparation for a crewed mission into orbit, NASA safety advisers are warning that the super-cold propellant SpaceX uses in their Falcon 9 rockets could be "a potential safety risk." When SpaceX is about to launch a rocket, they load it up with propellant at super-cold temperatures to shrink its size, allowing them to pack more of it into the tanks. "At those extreme temperatures, the propellant would need to be loaded just before takeoff -- while astronauts are aboard," reports Chicago Tribune. "An accident, or a spark, during this maneuver, known as 'load-and-go,' could set off an explosion." From the report: One watchdog group labeled load-and-go a "potential safety risk." A NASA advisory group warned in a letter that the method was "contrary to booster safety criteria that has been in place for over 50 years." The fueling issue is emerging as a point of tension between the safety-obsessed space agency and the maverick company run by Musk, a tech entrepreneur who is well known for his flair for the dramatic and for pushing boundaries of rocket science. The concerns from some at NASA are shared by others. John Mulholland, who oversees Boeing's contract to fly astronauts to the International Space Station and once worked on the space shuttle, said load-and-go fueling was rejected by NASA in the past because "we never could get comfortable with the safety risks that you would take with that approach. When you're loading densified propellants, it is not an inherently stable situation."

Greg Autry, a business professor at the University of Southern California, said the load-and-go procedures were a heated issue when he served on Trump's NASA transition team. "NASA is supposed to be a risk-taking organization," he said. "But every time we would mention accepting risk in human spaceflight, the NASA people would say, 'But, oh, you have to remember the scar tissue' -- and they were talking about the two shuttle disasters. They seemed to have become victims of the past and unwilling to try anything new, because of that scar tissue."

Comments

Yes and no

[religionofpeas]

There's always a risk that you're going to blow up if you climb in a rocket. If you don't want to accept that risk, don't climb in there.

Also, there has only been one case where a SpaceX rocket exploded during propellant loading, and timing analysis shows that a manned capsule would have been able to activate the emergency abort sequence, and escape the fireball.

https://gfycat.com/TenseClever...

Re:Yes and no

[arglebargle_xiv]

Also, NASA used cryogenic propellants for many manned missions. Pot, kettle, black.

Re: Yes and no

[Anonymous Coward]

While most people are not qualified to judge rocket safety risks, there is only one entity that has actually *demonstrated* that they are incompetent at judging rocket safety risks, and for that matter they did so spectacularly and totally, and then managed to stay in a position to continue judging rocket safety anyway and then did so again! That would of course be NASA, so I laugh when they judge someone else for being "too dangerous". It's still a hell of a lot safer than the deathtrap shuttle was. Next you'll be complaining it's too expensive...

Re:Yes and no

[nojayuk]

Also, NASA used cryogenic propellants for many manned missions.

Cryogenic fuel and oxidiser loading was complete before the astronauts entered the capsule or the Shuttle. Some extra LH2 and LOX was added as a top-up process during the rest of the countdown due to losses from warming.

SpaceX's ultra-cold higher-density LOX has to be loaded almost immediately before launch as it will warm up and expand and negate the advantage of its increased density if it's left too long in the rocket's tank. That requires astronauts on a man-rated Falcon 9 using higher-density LOX to be on board the capsule when the oxygen tank starts being filled. This is an extra risk over and above all the other risks of flying the cheapest bidder's hardware.

Re:Yes and no

[TheDarkMaster]

The gif is very interesting (and at least for me it seems that the abort system worked correctly and the capsule came out unscathed)

Re:Yes and no

[Rei]

I actually disagree.

If you're in the capsule, and there's an explosion, the launch escape system fires and you're safe.
If you're outside the capsule (or getting into it, but not yet to the point that you're strapped in and the abort system has been activated), and there's an explosion, you're dead.

The question is: are the odds of an explosion with the rocket pre-fueled, during the crew loading time, less than the odds of the crew escape system working? If no, then the SpaceX approach is safer. If yes, then SpaceX needs to fix their bloody crew escape system.

Re:Yes and no

[Joce640k]

So... invent a way to insert the astronauts very quickly after fueling.

I'm sure it can be done in a few seconds. What do they do at the moment, walk up the stairs?

Re:Yes and no

[vtcodger]

"There's always a risk that you're going to blow up if you climb in a rocket."

Of course. What's at issue is how great the risk is. Keep in mind that 133 of 135 Space Shuttle missions didn't kill anyone, but that the resulting 1.5% failure rate was generally felt to be unacceptable. It's a little hard to compute a failure rate for Falcon 9. Officially it's around 4% (two failures in 54 launches). But that doesn't count the vehicle that blew up on the launch pad in 2016 during static testing. OTOH, early lifetime failures for a new technology are probably more common than failures after the technology matures.

My gut feeling. Falcon 9 is fine for unmanned launches. For manned launches, it's maybe a bit iffy but it may get better over time.

Re:Yes and no

[Rei]

ED: "Are the reduced odds ... less than..." . That is to say, if the odds of an explosion during propellant loading are a 1 in 200, and the escape system has a 95% reliability, then the odds of an explosion during crew loading of a pre-fueled rocket need to be lower than 1 in 4000 for it to be safer.

Re: Yes and no

[Computershack]

While most people are not qualified to judge rocket safety risks, there is only one entity that has actually *demonstrated* that they are incompetent at judging rocket safety risks, and for that matter they did so spectacularly and totally, and then managed to stay in a position to continue judging rocket safety anyway and then did so again! That would of course be NASA, so I laugh when they judge someone else for being "too dangerous". It's still a hell of a lot safer than the deathtrap shuttle was. Next you'll be complaining it's too expensive...

The counter argument to that would be that they've had the experience to learn from so are better placed than Musk's Space-X to make such decisions.

Re:Yes and no

[Rei]

They don't do anything at the moment; there are none.

Re:Yes and no

[vtcodger]

Let's try a Muskian solution. We'll just bring the entire payload -- astronauts and all -- in via hyperloop and fire them into the air next to the rocket as the rocket lifts off. The payload will dynamically attach itself to the launch vehicle somewhere around 100 meters into the flight using giant magnets or a vacuum or something. Or maybe they'll just snare the lifting rocket using a giant net.

Re: Yes and no

[Megol]

So are you dishonest or stupid? Hard to tell those apart sometimes.

Re:Yes and no

[Sporkinum]

" Muskian "

Re:Yes and no

[Errol backfiring]

Now I see why Uranus jokes are so popular in the US. But somehow I don't think this "shoot the rocket in the butt" method will work.

Re: Yes and no

[bobbied]

Well.. Let's be fair about NASA's safety records...

NASA has demonstrated two things in their history. 1. They can be blind to obvious risks and become complacent about safety when what they are doing becomes too routine. 2. They can, and have, put excellent safety standards and practices in place and operate in very dangerous environments using very dangerous equipment in reasonably safe ways.

NASA has demonstrated both sides of the safety problem. They have made colossal mistakes, killed or nearly killed many people for stupid reasons AND they have learned from their mistakes, instituted safety practices that have allowed them to do amazing things with extremely few serious accidents and loss of life. They've made the stupid mistakes, and the hard decisions, in turn, and learned from the mistakes when they fell into complacency.

So, I think NASA is unique in it's qualifications for reviewing and determining space system's safety and their opinion carries a lot of weight. I also think that they are fallible as any other large organization, and they have a history of ignoring their risk management lessons learned in the name of expediency and efficiency.

So the question here is about SpaceX verses NASA in a discussion of risk management. I'm not sure we can dismiss either's opinions on the question. That means, we will need more information to decide. It may cost a lot of money to obtain the necessary information, it may take time and effort. I understand SpaceX is very sensitive to cost and schedule, but those pressures are what drove NASA into their various stupid mistakes. So I think NASA needs to be satisfied and SpaceX needs to prove what it needs to prove or change it's design.

Re:Yes and no

[Gavagai80]

It's a little hard to compute a failure rate for Falcon 9. Officially it's around 4% (two failures in 54 launches). But that doesn't count the vehicle that blew up on the launch pad in 2016 during static testing.

This is incorrect. CRS-7 was the only Falcon 9 mission to explode, unless you count the static fire test. CRS-1 was not a full success because it delivered a secondary payload to too low of an orbit, but it did take Dragon to the ISS without incident and that isn't the kind of failure that would endanger humans.

Re:Yes and no

[Rei]

Nor (to the best of my knowledge) has a crew escape system failed (although there have been some injuries).

Re: Yes and no

[arglebargle_xiv]

And that's safer? You're sitting on top of a fully-fuelled, giant flying bomb waiting to see if the launch will get scrubbed yet again (STS-61, STS-73). From memory one of the aborts for -61 was due to them losing a huge quantity of LOX with the crew on board, which doesn't make a strong case for fuel first, crew later.

Re:Yes and no

[rijrunner]

One of the more interesting accidents was back in the 1980's. Seems that a rocket family was designed to use pressurized gas to help keep the rocket frame rigid. That way, they could use less metal in the framework of the vehicle. Well, on the launch pad, after the vehicle was fueled, a technician working on the rocket bent over to pick something up. The screwdriver in his back pocket penetrated the skin of the vehicle and started letting the gas out. No way to stop the gas from leaking and eventually, the entire structure gave in and the vehicle was completely destroyed when it vented its fuel and the fuel caught fire.

Re: Yes and no

[fluffernutter]

Did you make a serious effort of challenging Autopilot by driving your test car through any routes that have changed in any way recently (eg. redesigned concrede dividers), or in any severe weather conditions? Did you try it anywhere where the road markings were sketchy? Or did you just drive it in perfect conditions and are now blowing smoke.

Re: Yes and no

[flygeek]

One thing needs to be clear: Autopilot does NOT navigate. It has no idea where it's going. It's just super cruise control, and if the driver tries to use it any other way then they are an idiot. It doesn't take more than five minutes of using it to figure that out; there are sketchy road markings and road construction zones pretty much everywhere, and if you can't pick up on its shortcomings after a few minutes of using it then you probably shouldn't be driving any type of vehicle.

That's actually a good thing, IMHO; if it was a lot better then I would be tempted to rely on it while I took a nap (I drive a Model S to work every day). As it is, it's a very helpful feature that takes a lot of stress out of the typical 20mph stop-and-go commute driving that I do every day; it excels at that so I can relax a bit and tune the radio.

Meanwhile, there's usually some idiot in a non-autopilot car next to me who is trying to drive and text his girlfriend at the same time; we'd all be better off if he had autopilot features, even if they aren't perfect.

Re:Yes and no

[Actually, I do RTFA]

There's always a risk that you're going to blow up if you climb in a rocket. If you don't want to accept that risk, don't climb in there.

I tried something similar with my replacement of "airbags" with "metal shrapnel bags". I explained the ballast helped steering, and looked cool. And I pointed out that cars have inherit risks. People still refuse to install them.</car_analogy>

Re:Yes and no

[sexconker]

How about they engineer a giant, styrofoam sleeve for the rocket?

Make 2 long pieces of curved styrofoam, with a little hole for the fueling port.
Slap em on the fuel tank.
Fuel up.
Load the crew and do pre launch checks.
Pull off the styrofoam.
Launch.

I bet a simple insulator gets close enough to whatever small percentage you get from fueling while crewed for them to not want to take the additional risk. Hell, the rocket koozie might even be better.

Re: Yes and no

[fluffernutter]

Please explain how a driver assist equipped car with an inattentive driver is worse than an inattentive driver without it.

The problem is that it is Autopilot that is causing drivers to *become* inattentive. So you're question is purposely misleading. The correct question is, "Please explain why it is a bad thing if a driver becomes inattentive due to Autopilot". Recent history provides the answer to that question.

Re: Yes and no

[fluffernutter]

Again, Autopilot causes some people to become inattentive. This is a fact. So please explain why it is still a good thing when you can't stop these people from buying it. I can agree that it would be better if everyone used it properly, but that just isn't human nature and won't happen.

Re: Yes and no

[Lab Rat Jason]

You forgot to mention that NASA (for all it's talk of neutrality) is a political organization, or at least exists only at the behest of politicians... therefore the political will of our leadership will influence culture and decision making, all the way down to the bottom. Perhaps their judgement of SpaceX is at least partially politically motivated.

Re: Yes and no

[Immerman]

Agreed. It doesn't matter how clear and concise the disclaimers are if the product itself doesn't take human nature into account. You've got a car that can drive itself without problems 99% of the time, the driver will inevitably stop paying attention to the road unless they have superhuman attention span.

Or unless they get lucky enough to personally have a few life-threatening close calls before they get comfortable with the system - in which case they *might* be able to maintain attention, provided they continue experiencing close calls often enough.

There's just not any middle ground for human nature - either a system needs at least frequent, moderate, interaction to maintain user attention, or it will go indefinite periods without getting ANY attention.

Re:Yes and no

[nojayuk]

I thought about something like that. See the Shuttle's External Tank for a working example of the technology, but...

"Pulling the styrofoam off" is another mechanism that could go wrong and possibly damage the first-stage tanks or maybe jam in place and prevent takeoff. It would be safer to launch the rocket with an insulating jacket in place (as the Shuttle did) but that adds weight to the stack meaning it uses up more fuel and reduces the payload to LEO, something the use of extra-cold oxidiser was meant to improve.

Everything is a risk, some things are riskier than others. Any modification intended to improve performance needs to be carefully examined for novel or increased risks -- SpaceX lost a rocket and payload when the use of super-cold oxidiser revealed a failure mode that should have been caught in the test lab long before it got to the pad. That sort of expensive and time-consuming testing is one thing that makes rockets pricey. Skipping the tests, trusting your suppliers and just running computer simulations of the hardware will be OK a lot of the time. Putting people on top of the stack without extensive and thorough testing of real hardware is another matter.

Re:Yes and no

[Lab Rat Jason]

This was an ICBM: https://www.npr.org/2016/09/15...

Also, a good audio production of the same: https://www.thisamericanlife.o...

Re: Yes and no

[Narcocide]

Why does everyone assume those two things are mutually exclusive? It doesn't take a lot of brains to lie and sound dumb at the same time.

Re: Yes and no

[HornWumpus]

I'd say just tune it to have a high false disconnect rate. In other words, force the driver to take control very very regularly, make turning it back on more than on button.

But then, what's the point?

I bet liability lawyers, plus promises made and cash accepted, end at that place (shitty 'autodrive' that disconnects constantly, to keep you awake).

Re: Yes and no

[bobbied]

You forgot to mention that NASA (for all it's talk of neutrality) is a political organization, or at least exists only at the behest of politicians... therefore the political will of our leadership will influence culture and decision making, all the way down to the bottom. Perhaps their judgement of SpaceX is at least partially politically motivated.

I don't think the claim of political bias necessarily invalidates NASA's view of SpaceX's design. In fact, I think that's actually a pretty poor argument in favor of SpaceX's view of the world.

There are two, maybe three, organizations in the world which have currently demonstrated safe manned space flight. SpaceX is not among them, but NASA is. SpaceX is a new perspective entry into a very elite group, they need to accept that NASA is where the government has developed it's expertise in manned space flight and if SpaceX wants to do this they will need to work WITH NASA on the question, much like aircraft manufacturers have to work with the FAA's "technical experts" when seeking approval for a new aircraft.

I'm not a rocket engineer and I have no dog in this hunt, but SpaceX and it's supporters need to argue their point based on the technical merit of the engineering, and not focus on the perceived political deficiencies or past technical failures of NASA. NASA has a point, that loading fuel is a dangerous process and exposes the vehicle and those near by to dangerous conditions. SpaceX has a point as well, that last min fueling allows them to pack more fuel into the same space for efficiency. The question is one of risk assessment, mitigation and management and what's acceptable for a man rated system, and NASA is the expert while SpaceX's job is to answer their objections.

Re: Yes and no

[bobbied]

While most people are not qualified to judge rocket safety risks, there is only one entity that has actually *demonstrated* that they are incompetent at judging rocket safety risks, and for that matter they did so spectacularly and totally, and then managed to stay in a position to continue judging rocket safety anyway and then did so again! That would of course be NASA, so I laugh when they judge someone else for being "too dangerous". It's still a hell of a lot safer than the deathtrap shuttle was. Next you'll be complaining it's too expensive...

That's not fair.. Sure NASA has historically made some real boneheaded moves that cost lives, but they have also FIXED their problems. They have also failed to keep the fixes in place and fell back into the processes and procedures and made new mistakes, had to reassess and fix the problems again. As BAD as NASA is/was they have experience at doing it right and diagnosis of what causes you to do things wrong. AND they've done all this in the full view of the public.

I think NASA needs to be taken seriously here and SpaceX has the burden of proof. SpaceX may be right, but like aircraft manufacturers have to work with the FAA, SpaceX needs to work with NASA and show how their system meets the requirements to be human rated.

But I wonder why SpaceX and/or NASA decided to put this into the public in the first place? This isn't a PR exercise, it's an engineering exercise of risk assessment and mitigation.

Re:Yes and no

[Anubis IV]

In talking with a four-flight NASA astronaut in 2002, I recall them mentioning that NASA pegged the odds of a catastrophic failure with the orbiter at about 1 in 40...which was a statement that came to mind just a few months later when Columbia exploded.

That said, after the initial batch, NASA wasn't building new orbiters, meaning that they had very little ability to iterate and improve. In contrast, and as you suggested, SpaceX has been able to learn from its mistakes and build new rockets in different ways, so it stands to reason that the odds ofany given launch failing should be better than what their historical failure rate might suggest. I.e. Even though their historical failure rate may be 2 in 54, the odds of launch #55 failing are less than that.

If their failure rate has been 3.7% up to now, and the odds of failure have gotten better since then, and the failure rate of the orbiter is the standard for what we consider acceptable, then the Falcon 9 may already be "good enough" for manned missions, or else very close.

Re:Yes and no

[WindBourne]

Actually, Tesla, along with AP has saved numerous lives already. Based on stats, Tesla with AP is actually MUCH SAFER than without it.

Re:Yes and no

[WindBourne]

What you hear here, is not what drivers are told. In addition, he had to have actually IGNORED the warnings since his hands did not go back in the last 5 seconds.
So, no. Tesla is doing fine with information. In fact, they take every new driver out and make sure that you are comfortable in all of them.

Re:Yes and no

[crunchygranola]

Also, NASA used cryogenic propellants for many manned missions.

Cryogenic fuel and oxidiser loading was complete before the astronauts entered the capsule or the Shuttle. Some extra LH2 and LOX was added as a top-up process during the rest of the countdown due to losses from warming.

SpaceX's ultra-cold higher-density LOX has to be loaded almost immediately before launch as it will warm up and expand and negate the advantage of its increased density if it's left too long in the rocket's tank. That requires astronauts on a man-rated Falcon 9 using higher-density LOX to be on board the capsule when the oxygen tank starts being filled. This is an extra risk over and above all the other risks of flying the cheapest bidder's hardware.

There are additional problems. It means that once the fuel is loaded there is a limited window to finish final checks and make the "go" decision. The "hold" time must be pretty short - but I have not seen a quote on how long it is. And that means if there is any unexpected delay in the launch after loading the mission must be scrubbed entirely, the astronauts must be taken off, and the fuel unloaded again. This also cuts into the purported advantage of being the low cost bidder if any launch hold results in a complete scrub (it is a hidden additional cost).

You don't load densified fuel unless the mission requires it, as reusing the launcher apparently does. So apparently the argument is that the astronauts need to be exposed to risk so that SpaceX can recover their launcher, thus lowering launch costs.

Maybe, just maybe, when crews are launched the launcher should be expendable.

Re:Yes and no

[mentil]

While slamming a Mountain Dew. I can imagine the commercial now...

Re:Yes and no

[sglines]

It should be noted that ALL manned flights by NASA had the same cryogenic propellants: liquid oxygen and either Kerosine or liquid hydrogen. Lots of them exploded before attempting a manned flight.

Re: Yes and no

[slashdotwannabe]

Even IF a certain percentage of drivers become more inattentive because of their usage of autopilot and do a shitty job of taking control in a timely manner, it's still going to be safer on a per-mile basis than human drivers, who are plenty good and being inattentive even without an autopilot*.

*I typed this comment on a smart phone while driving at 80mph**.

**OK, no I didn't -- but you get the point.

Re: Yes and no

[fluffernutter]

Ok well I'd like to see an actual study on that as opposed to believing someone on Slashdot.

Re: Yes and no

[slashdotwannabe]

That makes two of us. This is pretty new tech though so it's unlikely there is much hard data yet. Until then, about all you have is people speculating.

Ban it now

[Anonymous Coward]

We need to embrace a full risk aversion policy. Dangers of any kind have no place in a civilized society. No debate. Make me safe. #saynotorisk #sayyestolife #norisks #nodebate #safetynow

The Law of the Land, and NASA's Mission

[Zobeid]

Safety is NASA's top priority. That's not even their decision. A requirement that safety be NASA's top priority was passed through the Congress and signed by the President, and it's the law of the land. If they really take that law literally and fully comply with it, then the solution is to never fly. Astronauts are safest on the ground.

Besides, flying astronauts into space doesn't really advance the mission of our manned spaceflight program. If we *really* want to funnel federal money into established aerospace contractors and the right congressional districts, then the optimum way to do that is to endlessly develop spacecraft and never fly them.

Re: The Law of the Land, and NASA's Mission

[Anonymous Coward]

Driver's accident reports, cdc, and national highway issues, exercabated by the latest version of tax cut and infrastructure delays. Seems we are heading for the caves , not the stars.

Re:The Law of the Land, and NASA's Mission

[nitehawk214]

If safety is NASA's top priority, then they will never launch another person again. As that is, of course, the safest option.

Not that it should not be a prority at all, maybe, Third.

Re:The Law of the Land, and NASA's Mission

[Anubis IV]

Astronauts are safest on the ground.

Tell that to the family of the crew of Apollo 1.

shuttle cock(up)s

[harvey the nerd]

In the NASA scar tissue, there were known problems that NASA mgmt refused to honestly address before launches. In 1986, Challenger's freezeable, frozen seals. On Columbia, falling ice hits were a recurrent source of significant shuttle damage, that they specifically suspected a major hit on the fatal flight. Ice build up is an old problem with several solutions. Finally, NASA had a chance to image the fatal hole on Columbia in space, and didn't....

Too f'g many critical management failures...

Re:shuttle cock(up)s

[Baron_Yam]

> Finally, NASA had a chance to image the fatal hole on Columbia in space, and didn't....

To what end? They didn't have a patch kit, there was no rescue rocket on standby. There was no return plan other than 'de-orbit', and the shuttle could only come in tiles-first. And given the maximum altitude of a shuttle flight... they were coming back regardless (though they'd have run out their life support systems by about day 17, so they'd come back already dead when their orbit finally decayed).

Re:shuttle cock(up)s

[Headw1nd]

This is the same attitude that NASA took, which is pretty much why nobody trusts them anymore. Sticking your head in the sand doesn't allow for even the possibility of solution. If they had known the shuttle was going to break up on reentry they would have had the world's resources at their disposal. The idea that there was nothing in the world that could match orbit with the shuttle within two weeks is ridiculous (a soyuz took off to resupply the ISS February 2), and it's possible something could have been figured out to extend the life support.

Even if you really can do nothing and the shuttle is doomed you have an opportunity and an obligation to study the damage to the fullest in order to prevent it in the future. Instead they just decided they didn't want to know, because knowing would have involved hard choices and ignorance allowed them to proceed with the illusion that everything could work out fine.

Re:shuttle cock(up)s

[prisoner-of-enigma]

o what end? They didn't have a patch kit, there was no rescue rocket on standby.

Go read Comm Check. A Shuttle was close enough in pre-lauch prep that it could have been viable for a rescue. It would've required Columbia to power down everything and extend consumables as long as possible along with a faster-than-normal prep of the rescue Shuttle, but it was withing the bounds of possible. NASA simply decided not to even try.

Re:shuttle cock(up)s

[RKThoadan]

Ars has a great write up on it and an actual shuttle engineer added some information in the comments. The most obvious issue is that there was no way to prevent what happened to Columbia from happening to Atlantis (which was in the VAB at the time) and losing 2 shuttles. Link: https://arstechnica.com/scienc...

Re:shuttle cock(up)s

[chispito]

Ars has a great write up on it and an actual shuttle engineer added some information in the comments. The most obvious issue is that there was no way to prevent what happened to Columbia from happening to Atlantis (which was in the VAB at the time) and losing 2 shuttles. Link: https://arstechnica.com/scienc...

As opposed to every subsequent shuttle flight where they made a point to have a second shuttle on standby?

Re:shuttle cock(up)s

[jeff4747]

Because when one shuttle was fatally damaged by a not-well-studied-yet issue, the best solution is to rush another shuttle through the same process that caused the first failure.

What's your plan for ice damaging Atlantis's wing?

Re:shuttle cock(up)s

[jeff4747]

The subsequent shuttle flights were after they had studied how ice damages the shuttles. So they had a reasonable idea of what happened and what could happen in a future flight.

That was not something they could do before a rush-launch of Atlantis.

Re:shuttle cock(up)s

[prisoner-of-enigma]

While I agree there was no way to assure Atlantis wouldn't have a similar issue, the odds were against it. Coupled with the fact NASA had astronauts that would've lined up to volunteer for the mission it was something that should have been at least explored rather than dismissed out of hand. NASA has a history of coming through when management gets out of the way and the engineers are allowed to do what they do best.

Re:shuttle cock(up)s

[prisoner-of-enigma]

Agreed, but given how many missions prior to Columbia didn't have catastrophic failure the odds were against a similar repeat incident. Based on post-disaster comments, every astronaut at NASA would've volunteered for the mission immediately. If it'd been successful it not only would've saved the crew of Columbia, it would've been an incredible demonstration of what NASA can do when management gets out of the way and lets the engineers do what they do best. The rescue of Columbia could've been a rallying call for NASA just like Apollo 13 was. Instead seven people lost their lives and NASA's credibility to do anything right was dealt a serious -- perhaps permanent -- blow.

NASA has some of the most exceptional people on the planet in its ranks. Unfortunately it also has some of the most bureaucratic and inept managers as well. Pity the latter makes more decisions than the former.

And you think space flight is without risks?

[RStoney]

NASA culture revolves in part around the fact if they screw up, people get yanked in front of Congress and then get some pencil-pushing dweebs nit-picking them for the next year or so. Then come the law-suits for wrongful death. I would imagine that Musk has all kinds of legal waivers signed, an army of lawyers and risk mitigation through insurance. Plus sufficient lobby pressure via Senators / Representatives that want him to stay in business for their area. Kinda of different business models. As for fuel before they go - Let's give everyone a choice: One of Musk's rocket (Built to avoid lawsuits and for profit) vs. NASA (Product of lowest bidder)

Do you know what else is a safety risk? Rockets...

[e0b521bb9d0246d0b619]

Manned rocketry involves attaching humans to what is essentially a controlled explosion. There is always going to be a risk in this, regardless of when you trigger that explosion.

Walking across the street is a risk.

[techmage]

Everything is a risk. Rockets extremely so. Why is it that thousands can die in car accidents every year and that is considered acceptable but oh, change the way we do things on a rocket and that extra risk keeps the flight grounded? I understand the risks is rocketry. Things can go south real fast. You need to mitigate the risks, not try to eliminate or ignore them. Every time you launch, you risk losing the payload or the crew. What that percentage is you only find out after you fly a number of times (the more you fly the more you know). SpaceX has launched over 20 times with densified fuel. The SLS has flown zero times. I think SpaceX is in the lead on this risk situation.

Re:Walking across the street is a risk.

[HornWumpus]

Cardiovascular Russian roulette is the world's most popular X-sport.

Known risk vs unnecessary risk

[sjbe]

There's always a risk that you're going to blow up if you climb in a rocket. If you don't want to accept that risk, don't climb in there.

There is a difference between accepting a known risk and accepting an unnecessary risk.

Also, there has only been one case where a SpaceX rocket exploded during propellant loading

One case is more than enough to warrant caution. SpaceX has had approximately 50 launches so far. That's an approximately 2% failure rate which is alarmingly high. Two shuttles were lost at that rate of failure. I'm all for pushing the envelope but that doesn't mean we should say "hold my beer" and ignore known risks that could be mitigated.

Re:Known risk vs unnecessary risk

[religionofpeas]

There is a difference between accepting a known risk and accepting an unnecessary risk.

Loading densified propellant is a known risk with calculated benefits.

Re:Known risk vs unnecessary risk

[jellomizer]

Modern Human Space travel is almost always considered an unnecessary risk. With current technology the main reason for sending humans, is mostly for the marketing benefit, of letting us know that we can leave the planet if needed.

That said I do support man space flight. To the Moon and Mars.Knowing that it is a high risk activity. But I see it important for our survival is to expand to new areas.

The argument for unnecessary risk could be applied to the European explorers who were trying to find different routes to the "Far East" to trade with them, without paying Italy for being the Middle Man.

Re:Known risk vs unnecessary risk

[thegarbz]

There is a difference between accepting a known risk and accepting an unnecessary risk.

Whether the risk is unnecessary depends on the engineering constraints and the rewards. A rocket could explode. We don't *need* a manned space program. The entire space program could by many be deemed as an unacceptable risk given the cost of the equipment that can be lost.

Re:Known risk vs unnecessary risk

[Type44Q]

which is alarmingly high

It would be, if that 2% figure applied to their current "production" - or any future man-rated - designs.

A fledgling rocket company that wants to open the Greatest Fucking Frontier to the World and isn't willing to break a few eggs... isn't going to learn how to make a fucking omelet. Anyhow, their designs are evolving at such a high rate that it might be some time before they even go into a true "production phase."

What?

[rotorbudd]

Liquid hydrogen and oxygen are OK, but cold kerosene and liquid oxygen aren't?

Clickbait title

[TheDarkMaster]

I fail to see any difference between "load it up with propellant at super-cold temperatures to shrink its size" and "load it up with liquid hydrogen and liquid oxygen", where, as far as I know, manned rockets have been loaded that way since the Apollo missions.

Re:Clickbait title

[worf_mo]

The difference would seem to be that the "load it up with propellant at super-cold temperatures to shrink its size" step is required to take place with the crew already on board. Which I am sure has a different risk level than "load it up with liquid hydrogen and liquid oxygen, and if the whole thing hasn't exploded proceed with getting the crew aboard."

I still agree that the title is pure clickbait.

Re:Clickbait title

[TheDarkMaster]

What I meant in my question is what would be the difference because the liquid oxygen/hydrogen is already something condensed and at very low temperatures. Or is it possible to cool and condense it even more than is normally used?

Re:Clickbait title

[Strider-]

The issue, and concern, is that loading propellants is a dynamic process. The rocket is going through transients as the mass and temperature changes. Traditionally, the astronauts were loaded into the vehicle once it has got steady state, NASA's concern is that doing the dynamics with the astronauts aboard is an additional risk.

Boeing involvement

[prisoner-of-enigma]

Does anyone else find it convenient the guy most closely associated with Boeing -- you know, that company with the multibillion-dollar vaporware SLS rocket contract -- is squawking the loudest about this?

Nah, no conflict of interest here. Move along folks.

Solving a known failure mode

[sjbe]

Demanding as close to zero risk as possible in spaceflight missions is good for the few humans aboard, but slows development of the field for the rest of mankind.

There is a difference between accepting a known risk and accepting an unnecessary risk. In this case there has been a concern raised based on a previous rocket exploding under similar conditions. It's not unreasonable to insist that we solve or mitigate a known failure mode prior to putting people on board the rocket. It's not to say SpaceX cannot use this procedure but rather that they will have to do some work to prove that is reasonably safe compared to known proven methods.

It's why I've always assumed a nation such as China would lead the space revolution.

Should that happen it will be because China had the political will to invest heavily in their space program whereas we did not. China doesn't want to blow up their people any more than we do. But failure modes can be solved with adequate investment. Countries that lack the political will to make space exploration a priority will inevitably take a back seat to those countries that do.

Re:Solving a known failure mode

[religionofpeas]

It's not to say SpaceX cannot use this procedure but rather that they will have to do some work to prove that is reasonably safe compared to known proven methods

They have extensively studied the cause of the explosion, and have made modifications to minimize the risk of it happening again. NASA will have to decide whether that's sufficient.

Dragon pad abort

[Anonymous Coward]

Even Mercury and Apollo planned to escape an explosion, they used wires running down the length of the rocket, and if a sufficient number of wires ceased to have continuity, the sequence was triggered.

The same NASA that used the shuttle boosters?

[Opportunist]

You know, the solid-fuel booster rockets on the shuttle that cannot be shut down once started? That's the NASA that is now so concerned over security problems?

Von Braun, back in the 60s, already knew that you cannot really man-rate those things exactly because you have zero control over them once they went off. And they now have a problem with "security concerns"?

I smell a government agency having a problem with seeing their last reason to exist vanish.

Re:The same NASA that used the shuttle boosters?

[bobbied]

You know, the solid-fuel booster rockets on the shuttle that cannot be shut down once started

The shuttle system dealt with that by making the solid fuel boosters detachable. Yes, there where phases in flight where this would/could be a problem, but after you reached a specific altitude, abort simply involved detaching from the solid boosters.

By the way.. This isn't all that large of an issue. You may have had the ability to throttle a Saturn 5's engines, but you cannot stop and start them. Serious problems in the first stage would cause nearly the same sequence.. Stage 2 fires and you accelerate away from the problem...

Re:The same NASA that used the shuttle boosters?

[Opportunist]

You CANNOT detach them safely before they burn out, that's the problem. The boosters provide nearly all the thrust at liftoff and actually very far into the flight. They burn at 100% thrust and will continue to do so for as long as there is fuel. No way to shut them off. No way to control their thrust.

There was exactly one phase where this is a problem. From T0 when they ignite to T120 when they're burned out and are jettisoned. That's correct. Other than those 2 minutes, they're no problem at all...

And no, you could not throttle the F1s of the Saturn V S-IC. They ran at 100%, no other option. But you could turn them off. That alone made them heaps safer. Actually, the center F1 was routinely turned off during ascent.

Re:The same NASA that used the shuttle boosters?

[bobbied]

Sorry, you are correct.... I went and educated myself and determined my assumptions where wrong. Once ignited, you have a 2 min ride WITH the SRBs, no exceptions which are likely survivable.

Saturn 5 manned launches where equipped with a Launch Escape System, which was designed to yank the command module off the top of a malfunctioning rocket and away from danger and high enough to deploy the main parachutes. But there came a point where even this system was ineffective/unnecessary (20 seconds after stage 2 starts) so it was ejected. Also, engine throttling wasn't possible on the Saturn 5, though individually shutting them down WAS possible, and indeed planned to reduce thrust to keep acceleration in check as the vehicle burned off fuel and provide a measure of redundancy should one or more engines fail.

Re:The same NASA that used the shuttle boosters?

[Lab Rat Jason]

Sorry, you are correct.... I went and educated myself and determined my assumptions where wrong

Holy shit! Do you have any idea what site you're on?!?!? You can't talk like that here!

Re:The same NASA that used the shuttle boosters?

[swillden]

You know, the solid-fuel booster rockets on the shuttle that cannot be shut down once started? That's the NASA that is now so concerned over security problems?

Von Braun, back in the 60s, already knew that you cannot really man-rate those things exactly because you have zero control over them once they went off. And they now have a problem with "security concerns"?

They aren't allowed to learn from past mistakes?

Note that I'm not saying that there's a real problem here. I don't know. But it's not unreasonable to ask questions and evaluate tradeoffs, indeed its the absolute most rational way to proceed.

Re:The same NASA that used the shuttle boosters?

[Opportunist]

Of course you're allowed to learn from past mistakes. NASA always did, fortunately. But with the SBRs they added a huge mistake to something that was already far from feasible. The shuttle didn't achieve what it was supposed to, not by a longshot. What we wanted was a cheaper replacement for the throwaway capsules of the past, something we could reuse over and over for multiple trips. What we got was an overhyped, WAY over budget and way too expensive kinda-sorta-at-least-partly-reusable space craft... well, reusable... reusable after it spent enough time and money putting it back together that it would have been faster and cheaper to build a new one.

The shuttle was a failed concept, to be honest. But it was a prestige object. Maybe the first "too big to fail" thing we had. Frankly, single-use rockets like the Russian used were the right way. Easier (very Russian technology, easy to build, easy to maintain and when in doubt, bang with a hammer), cheaper and, especially as the shuttles aged, WAY more reliable. The last time a cosmonaut died in a Soyuz was in 1971. Given the recent track record, it's safer in the capsule on top of the rocket than in its vicinity before liftoff...

Re:The same NASA that used the shuttle boosters?

[strikethree]

I smell a government agency having a problem with seeing their last reason to exist vanish.

It is correct for you to be suspicious; however, your reason is specious. The first A in the NASA acronym is why you are wrong. They are not just 'S' administration.

I assume the 'agency' having issues with this is not actually NASA but another contractor prompting/forcing NASA to be afraid to give their assent since the downsides of assent are immediate and the rewards are off in the distant future. The best NASA can hope for is for nothing to happen... and in the real world, something is always happening.

Irresponsible

[sjbe]

If you're in the capsule, and there's an explosion, the launch escape system fires and you're safe.

That's like saying that we shouldn't worry about safe refueling procedures on an F15 because it has an ejection seat. That's incredibly irresponsible and almost weapons grade stupid. Emergency escape systems are nice to have but not something you want to depend on since they are almost as dangerous as the problems they protect against. Furthermore explosions can happen MUCH faster than any escape system could carry the crew to safety. Ejection systems only help with failure modes where you have some amount of time to react. Rockets are fast but not instantaneous.

The question is: are the odds of an explosion with the rocket pre-fueled, during the crew loading time, less than the odds of the crew escape system working?

You don't work in risk management do you? That is NOT the correct analysis. If you actually are relying on the escape system rather than designing a safe refueling procedure then you have a poorly designed rocket and incompetent engineers. You use escape systems for to mitigate risks that cannot be further mitigated which isn't the case here. If SpaceX is using unsafe fueling procedures then you redesign the fueling procedures until they are safe. This might involve blowing up a few more (hopefully unmanned) rockts first. You do not say "YOLO" and hope the escape system will protect your ass from incompetent engineering.

Re:Irresponsible

[religionofpeas]

If SpaceX is using unsafe fueling procedures then you redesign the fueling procedures until they are safe.

Sure, you also need to weigh other factors. Late fueling is a deliberate design decision that offers higher efficiency. A rocket involves many trade-offs between safety and efficiency. If you'd maximize safety in every case, it wouldn't be able to lift off.

Re:Irresponsible

[Rei]

That's like saying that we shouldn't worry about safe refueling procedures on an F-15 because it has an ejection seat.

Does anyone worry about an F-15 exploding during fueling? No? Then your example doesn't work. People stand right next to F-15s while they're fueling, and they're also fueled midair.

Indeed, the whole point is to get the vehicles to the point that nobody worries about them exploding.

That's incredibly irresponsible and almost weapons grade stupid. Emergency escape systems are nice to have but not something you want to depend on

Exactly. They're for emergencies only. Are you telling me than an explosion isn't an emergency? No, they're not comfortable, but they save lives.

What's your "emergency escape" for people standing outside a rocket or not yet strapped in when it explodes? None, that's what. They're dead.

Furthermore explosions can happen MUCH faster than any escape system could carry the crew to safety.

No. And indeed, if that were the case, it wouldn't be an emergency escape, and wouldn't be approved.

If you actually are relying on the escape system rather than designing a safe refueling procedure then you have a poorly designed rocket and incompetent engineers.

Every system has a probability of failure. Period. The chance of a refueling failure will never be zero. Nor will the chance of a pre-fueled rocket exploding on the pad during crew failure. A proper analysis of failures has one metric: crew safety probabilities. And safety systems are very specifically a part of that. You cannot just discount the risk of people being killed during crew loading like you wish to. One obviously want the fuel loading risk to be as low as possible when crew is pre-loaded, just like one obviously wants the crew loading risk to be as low as possible when they're not. That doesn't mean you can just pretend that the former has all the risk and the latter has none, or that the availability vs. lack of emergency safety systems is irrelevant.

Re:Irresponsible

[Rei]

Also, for the record, your "weapons grade stupid" is the exact analysis that NASA uses. The requirement is a less than 1:500 chance of a fatal accident during launch, including launch escape systems. Rockets aren't required to have a "1:500 chance without the escape system firing".

And really, the above linked gif is for the worst case - pressure vessel failure (aka, instantaneous) on the upper stage. You don't get any faster "failure explosion propagating to the payload" scenario faster than that. Yet if that were a crewed Dragon 2, they would have survived..

"The escape system slated for the second version of Dragon would have — should certainly have taken the astronauts to a safe place after an anomaly like this," Shotwell said during a news conference following the accident Sunday. "In fact, it's designed to take a far more energetic event and get the astronauts safely away."

Furthermore:

Interestingly, the robotic Dragon apparently managed to survive Sunday's rocket explosion, at least initially, even though the capsule was right in the middle of the fray, SpaceX representatives said.

"We did have Dragon telemetry after the event, so Dragon was transmitting and appears to have been healthy for some period of time," Shotwell said.

The fact that the (much poorer protected) Dragon 1 survived is apparent by the fact that Amos 6's propellant didn't explode until the payload fell to the ground.

Re:Irresponsible

[Immerman]

Or you could do it the NASA way and design a "safe" rocket without any escape options, then ignore the engineers' warnings about operating O-rings out-of-spec, and blow everyone up with no hope of escape.

Re:Irresponsible

[Anonymous Coward]

You don't work in risk management do you? That is NOT the correct analysis. If you actually are relying on the escape system rather than designing a safe refueling procedure then you have a poorly designed rocket and incompetent engineers. You use escape systems for to mitigate risks that cannot be further mitigated which isn't the case here. If SpaceX is using unsafe fueling procedures then you redesign the fueling procedures until they are safe. This might involve blowing up a few more (hopefully unmanned) rockts first. You do not say "YOLO" and hope the escape system will protect your ass from incompetent engineering.

There are different risks to manage. There is the risk of a fueling explosion, and there is the risk of dying in such an explosions. The risk of explosion is minimized via design features to the extent practical. Since the risk of explosion is not totally eliminated, the risk of dying in the explosion must be managed. That is mitigated using an escape system.

Re:Irresponsible

[q_e_t]

This is why NASA improved safety procedures.

Re:Irresponsible

[q_e_t]

Normally it is mitigated by not being on the rocket. No astronauts have died in a rocket fuelling accident when not being there.

Re:Irresponsible

[Immerman]

Granted, but there's still only very minimal bailout options for the crew of the Shuttle - anything goes catastrophically wrong once they leave the launch pad, they're probably dead. A reliable "any time" bailout option means you can allow much higher risk profiles for other risk modes while maintaining the same overall crew safety level.

Not that there isn't always room for improvement - but when every launch involves dozens of new changes to the rocket there's a limit to how safe you can really make things. I suspect that's part of the goal behind the "mature" Block 5 - the design will rapidly stabilize, and allow meaningful determination and certification of safety levels.

Re:Irresponsible

[q_e_t]

I wish I could mod that up.

Re:Irresponsible

[vtcodger]

"If you'd maximize safety in every case, it wouldn't be able to lift off."

Or you could just not fuel it -- ever. That'd be pretty safe

But the real problem was described by Richard Feynman in 1986 in his Appendix F to the Rogers Report on the Challenger Disaster. https://science.ksc.nasa.gov/s...

" It appears that there are enormous differences of opinion as to the probability of a failure with loss of vehicle and of human life. The estimates range from roughly 1 in 100 to 1 in 100,000. The higher figures come from the working engineers, and the very low figures from management. What are the causes and consequences of this lack of agreement? Since 1 part in 100,000 would imply that one could put a Shuttle up each day for 300 years expecting to lose only one, we could properly ask "What is the cause of management's fantastic faith in the machinery? ..."

Well worth reading and still applicable I think.

Re:Irresponsible

[phayes]

Space-X has _never_ had an incident when fueling F9s using the current loading protocols - neither in the thousands of fueling tests they have performed nor on 30 odd launches since they started using sub-cooled propellants. It was only with pre-block-5 COPVs using the accelerated loading protocols that they were testing to be able to hold longer at the last minute before aborting and defueling the stack that they had the problem with AMOS-6 (confirmed in testing).

Block 5 COPVs (First launch: tomorrow) have been redesigned to eliminate the problem and they will almost certainly be re-using the accelerated loading protocol in the future - but at least initially, not on manned launches. If the Block 5 fixes have proven to have eliminated the issue and after that has been proven through continued launches using it without any issues, at some point even NASA will have to admit that it is a solved problem.

Re:Musk Doesn't Care About Risks

[pezpunk]

your pathetic salty jealousy is hilarious.

Risk maganment

[rkordmaa]

Being around a loaded rocket is inherently risky business. But if you have to be there, then surely your personal escape capsule is the safest place to be. Astronauts on the way to loaded rocket and ground crews wouldn't be so fortunately equipped. Rocket might blow up during propellant loading, but it might also do that any time after it's loaded, say while the astronauts are climbing in.

Re:Risk maganment

[ColdWetDog]

It seems like you all are forgetting all the trouble NASA went to protect Apollo astronauts against catastrophic pad failures.

These structures were built into the pad to try to allow astronauts to escape the Saturn V in the event of a not-so-catastrophic-but-close-to-it pad failure.

And the infamous slide wire (which, IMHO, should not have been disassembled, it should have been referbered and opened up to the public for a fee....)

NASA was VERY worried about pre launch Rapid Unscheduled Dissassembies. That none ever happened is testimony to procedure, training and engineering.

Why we haven't returned to the moon in 50 years

[bfwebster]

This thinking pretty much sums it up. Experimental/exploratory aviation is inherently risky. NASA has squatted on its haunches for half a century; no human had left low-earth orbit (LEO) since 1972. Idiots like these want to make it another 50 years. Good luck with that.

what a question

[e**(i pi)-1]

does a car, bike, train plane put lives at risk? yes. The question is always whether it is worth taking the risk. In space exploration the risks are higher, but it is also more exciting and beneficial.

Obvious outcome

[skovnymfe]

SpaceX will hire their own astronauts and send them to space.

Re:Obvious outcome

[religionofpeas]

SpaceX will hire their own astronauts and send them to space.

With blackjack and hookers.

Re:Musk Doesn't Care About Risks

[jellomizer]

Why shouldn't we be jealous. Who wouldn't want to be the leader of Mars?
Global Warming would be a good thing!
Labor dependent on your resources, they cannot quit, or afford to be unproductive.
causing 0% unemployment, and 0% homelessness.
History will mark you as the first leader of Mars.
if Earth gets destroyed then you become the leader of the human species.

NASA "Advisors"

[bradley13]

Low temperature fuel. Like the LoX and liquid hydrogen used by the Space Shuttle? This complaint doesn't even make sense.

A quick read through TFA, and the second linked article: it's not NASA saying this, it is some unknown group of NASA "advisors". The only person specifically named worked for Boeing. Which is to say that SpaceX's competitors are concerned. The fact that NASA has allowed those competitors to speak to the press as "NASA advisors" just shows the level of corporate cronyism present in the game. And, yes, NASA could stop them - if they were really serious, it would be "contact the press and demand a retraction, or contract xyz is cancelled".

ULA has got to be seriously scared. As in "need a change of underwear" scared. It's all well and good to suck up overpriced contracts, as long as any competition is held at bay with overregulation. However, when a competitor not only jumps the regulatory hurdles, but is 1/10 the price, _and_ has an actual product, as opposed to vaporware... Well, there comes a point where the cronyism is seriously endangered.

ULA will get nasty before they give up - this is just the warm-up. I hope SpaceX has good lawyers, and also a really good security force. I expect all sorts of staged lawsuits - maybe some class actions if they can find an excuse. Meanwhile, a well-placed bullet hole in the fuel tank of a launching rocket might dent that safety record.

Re:NASA "Advisors"

[Hylandr]

Bradly13 is on point.

This is just the competition FUD mongering over spaceX.

You need to sit down.

This late?

[The Cynical Critic]

One thing that perplexes me somewhat is that they're only raising this concern just now (at least publicly) when the human-rated Dragon 2 capsule for the Falcon 9 was announced in 2014 and is supposed to make it's first human-crewed flight this year. You'd have thought that they would have raised this issue years ago considering the Falcon 9 has been using liquid oxygen and RP-1 (highly refined kerosene) ever since the beginning. The only change from the pre-2015 rockets in terms of fuel is that they're not just chilling the oxygen, they're also chilling the RP-1.

I'm also really not convinced of the safety concerns as the basic LOX-RP1 combination is probably the most common fuel for big rockets trough history, having been used in legendary rockets like the V2, the R7 (which took up Sputnik and Gagarin), the Saturn V, Atlas and even the main engines of the Space Shuttle.

Re:This late?

[gweihir]

Probably part of a stock-manipulation attempt, as others here have already pointed out.

Re:This late?

[Strider-]

I'm also really not convinced of the safety concerns as the basic LOX-RP1 combination is probably the most common

The issue isn't so much the propellants in question, but loading them while the astronauts are already onboard. Losing propellants into the rocket is a dynamic process, as the structure cools, and takes the structural loads of that propellant. Until now, the procedure has always been to load the rocket first, allow it to reach steady state, then load the astronauts. Because of the sub-chilled propellants, SpaceX can't do this as the propellants will warm up.

Re:This late?

[ColdWetDog]

Densification. It's not for rocket fuel anymore.

Re:This late?

[Gavagai80]

There was no reason for this concern before as SpaceX only recently started the late propellant load. Of course, there is a very simple solution for it -- launch the old way. Which was SpaceX's stated plan at the time they switched to supercooled -- they planned to do supercooled most of the time but to not use it with astronauts. Apparently that plan has changed as they've gained more experience.

Re:This late?

[aslagle]

SpaceX has been using densified LOX since December 2015. Not exactly yesterday.

Re:This late?

[jeff4747]

and even the main engines of the Space Shuttle.

Quibble: The SSMEs used liquid oxygen and liquid hydrogen, not RP1

It is the Tesla shorts pre emptive strike.

[140Mandak262Jamuna]

Tesla is the most shorted stock in the history of options trading by the money at stake. Just before the conference call last Monday, the short interest was 33% of the float, stocks being traded. 12 billion dollars. There was huge hype prior to that. But Tesla beat the lowered expectations. (That is it lost "merely" 750 million dollars in one quarter, not the 1.5 to 2 billion they were expecting). So the stock fell by 10% in after hours, and is hovering with just 5% loss over last week. 700 million of the shorts were "in the money" and 11 billion is still in the hole. They are carrying a paper loss of 11 billion dollars, and they need to keep reserves to avoid a margin call. It is costing them 1 million dollars a day to maintain the short position.

The talk in the street is, Space X will rescue Tesla. Musk has used Tesla to rescue Solar City. If he can use publicly traded company for a bailout, it would be easier, (not easy, but easier ) to persuade SpaceX backers to get him over the cash crunch in Tesla. That is why he is shunning equity markets. He was asked a very leading question, "Even if you dont need equity but it is advantageous sometimes, so would you ... blah blah blah" and Musk snapped back, "I dont want to:. His performance was derided, called flaky, and very negative press was generated by the way he snubbed the professional analysts and let one you tube fan of Musk dominate the earnings conference.

The shorts are taking pre emptive action here to put some crimps on SpaceX to stymie, thwart or at least put a crimp to this option. It is even possible Musk's erratic conf call is deliberate, to make the shorts take even stronger positions. The short interest actually increased after the earnings call, but still there is a 11 billion dollar margin calls hanging over the heads of the shorts. Just when the options come due, Musk can do a "BTW this happened" tweet and catch them once again like he did last year. The shorts lost 2.5 billion dollars on a falling stock!.

So take all this with a liberal dose of salt. Disclaimer: I don't own Tesla stock nor do I short it, in fact I dont trade on individual stock or options. Not a owner now, but I am getting a Model 3 soon.

Re:It is the Tesla shorts pre emptive strike.

[angel'o'sphere]

How do you know how many people or "money" do short a certain stock?

Re:It is the Tesla shorts pre emptive strike.

[140Mandak262Jamuna]

Raw data is published like this: https://www.nasdaq.com/symbol/... And there are sites that will consolidate and present it for irregular users and for news stories. I am not a trader so I only look at the news stories covering shorting of Tesla. I was only trying to see if my 1000$ deposit is gone or if there is some hope someday some car might materialize.

Re:It is the Tesla shorts pre emptive strike.

[140Mandak262Jamuna]

https://www.investopedia.com/n...

Re:It is the Tesla shorts pre emptive strike.

[angel'o'sphere]

Does not answer the question, how do they know who (how much) is shortening a certain stock?

Re: It is the Tesla shorts pre emptive strike.

[akical0118]

Because there's a public register of option calls short or put one nasdaq's site? Kinda how the market speculates on the value of a stock.. 101 type shit....

Re:It is the Tesla shorts pre emptive strike.

[140Mandak262Jamuna]

Option trades are like stock trades. Anonymous, so no one should know who is shorting. Number of people is never known. Volume of trade is public information.

Re: It is the Tesla shorts pre emptive strike.

[angel'o'sphere]

Well,
perhaps my idea what a "short" is wrong.

You sell shares you don't have, based on a kind of "credit".

Why and how would there be a public register? The whole idea of "going short" would not work if you had to register your trades.

Options might be another issue.

Re:It is the Tesla shorts pre emptive strike.

[angel'o'sphere]

That is actually a good point.
But has nothing to do with "shorting" unless you want to say a put option is a shot, too. (I'm not an expert with such silly american terms ;D if I had put options on the market and one would ask me I would say: "I bought some put options" ... simple)

Re:It is the Tesla shorts pre emptive strike.

[Hognoxious]

But has nothing to do with "shorting" unless you want to say a put option is a shot, too.

By definition it is. The option gives you, in return for a non-refundable premium, the right (you may choose not to exercise it) to sell some asset at a specific price X (until date Y, yada yada). You might not in fact even own even own that asset - that's a naked put.

So, the asset goes down to W, which is below X. My counterparty is legally obligated to buy at X. I can buy on the open market at W, and I pocket X - W.

The asset goes up. I don't oblige the counterparty to do anything. I lose my premium.

All Technology Creates Risk.

[JimSadler]

When men discovered horse shoes surely there were deaths in mining the iron, blacksmithing the shoe and an occasional brain of a by stander getting whacked by a flying horse shoe. When Columbus discovered America it was on a wooden ship. wooden ships constantly fell apart and all hands were often lost. That was due to the technology of building wooden ships. So maybe a rocket launch should be done several miles from any town or suburb. But anyone who think space related events will not kill people is just plain silly. I wonder how many people died in the process of making buggy whips.

It has to be proven better

[sjbe]

A rocket involves many trade-offs between safety and efficiency.

Of course it does. That's not adequate justification for throwing caution to the wind. You use a new procedure because it is either more efficient (cost and/or performance) with similar safety or safer with comparable efficiency. In this case it is obviously a performance improvement but it isn't yet clear if that comes at an unacceptable increase in risk. To argue that astronauts should just shut up and strap in without appropriate investigation of the risks they are taking is a dumb way to run a space program. You don't change something that is working unless it is unambiguously better.

If you'd maximize safety in every case, it wouldn't be able to lift off.

Maximizing safety does not equal perfect safety and no one claimed otherwise. That does equate to carte blanche to implement every idea that pops into the minds of SpaceX engineers. If the idea is an improvement (price/performance/safety) then they should be able to prove it to the satisfaction of NASA. If it isn't then that's unfortunate but they'll have to figure something else out

Re:It has to be proven better

[religionofpeas]

To argue that astronauts should just shut up and strap in without appropriate investigation of the risks they are taking is a dumb way to run a space program

That's why nobody is doing that. Teams from SpaceX, NASA, FAA, and USAF, have been working for months trying to understand the details of the explosion. As a result, they've modified their fuel loading procedure, and proposed longer term updates to their oxygen tank design.

If it isn't then that's unfortunate but they'll have to figure something else out

Or NASA finds another rocket to take their astronauts. Or we just keep them on the ground.

Re:It has to be proven better

[Strider-]

The design changes were made to the helium tanks, not the LOX. The Amos 6 conflagration was caused by solid oxygen crystals forming in the composite wrap around the He tanks

Re:It has to be proven better

[prisoner-of-enigma]

That's not adequate justification for throwing caution to the wind.

You realize you're backing the same agency that decided to fly the very first Shuttle mission as a manned mission without a full-up unmanned test beforehand. That had never been done in all of NASA's history. You're also backing the agency that decided to fly manned missions with strap-on solid rocket boosters, something also not done in any of NASA's history since they cannot be throttled and there is no survivable abort mode while they're firing. You're also backing the agency that allowed a heat shield specified to not be impacted by debris and then stuck it on the side of a giant cryogenic fuel tank guaranteed to cause ice debris (indeed, debris damage to the heat tiles was consistently noted and ignored from the very first mission). You're also backing an agency that specifically designed a Shuttle that has no reasonably-survivable abort modes other than Abort-to-Orbit (ATO) and no survivable aborts if anything goes wrong during re-entry or landing.

When compared to that, SpaceX looks downright hypercautious.

Re:It has to be proven better

[Xylantiel]

The Amos 6 conflagration also took place during the test-fire. i.e. there would not have been crew in the capsule during that operation anyway. Heck SpaceX doesn't even usually have PAYLOAD on during that operation, but the customer opted to do that. And in any case, your point just indicates that the Amos 6 failure is not relevant to the discussion of late-loading of propellants, whereas many of those arguing here that SpaceX rockets are not safe are using it as an example of how late-loading of propellants is unsafe.

Re:It has to be proven better

[eth1]

Or NASA finds another rocket to take their astronauts. Or we just keep them on the ground.

Also, people seem to forget that the Space Shuttle killed an average of 1 crew for every 10 missions over its lifetime (or was lost with all hands once every ~70 missions). Those really aren't good odds when you think about it like that, but it was good enough, apparently. Humans are fragile, and getting into space with current tech requires controlled violence.

Re:It has to be proven better

[Thelasko]

As a result, they've modified their fuel loading procedure, and proposed longer term updates to their oxygen tank design.

The proposed changes are complete. Falcon 9 Block 5 has many changes to improve reliability and safety. Updates to the oxygen/helium tanks are just one of many.

Keep in mind, SpaceX has a major advantage in safety and reliability that others don't have. They have recovered their boosters in tact. I'm sure they have torn them down to do detailed analysis on how the components hold up in flight. No other launch provider can do that.

Re:It has to be proven better

[taiwanjohn]

Why don't they just skip the fuel densification for crewed flights? Even without it, the F9 would still have plenty of lift to put a Dragon-2 in LEO.

Re:It has to be proven better

[Lab Rat Jason]

Also important to point out that the shuttle didn't have an _actual_ abort contingency during the solid boost phase... They could decide to abort during that time, but couldn't execute an abort until the burn was done; the shuttle itself couldn't detach from the tanks and veer off at low altitude. This was a risk that was built in to the design, and possibly contributed to the loss of the Challenger crew. I'm not sure if they had enough warning ahead of time, but the design definitely prevented them from jettisoning the boosters.

Re:It has to be proven better

[Lab Rat Jason]

I agree with what you are saying, but I though the shuttle had an abort to europe profile that didn't include a go-around orbit. Maybe I'm mis-remembering.

Re:It has to be proven better

[Xylantiel]

To me that is one of the reasons this feels like a manufactured hit piece by Boeing. Presumably skipping the densification would decrease their maximum crewed mass to LEO enough to be useful as a negotiation point to Boeing. Otherwise this just seems like one point in what must be a huge matrix of risk assessment, since it also appears to be at least partially mitigated by the capsule escape system. But it isn't unusual to want two layers of safety, but this all just seems too simplistic.

Re:It has to be proven better

[jeff4747]

but I though the shuttle had an abort to europe profile that didn't include a go-around orbit.

Theoretically, the shuttle had 4 abort modes.

Very early in the flight, they could abort back to FL. This was considered insane to actually try and unlikely to actually work.

Shortly after that window, they could theoretically abort to Africa/Europe, but the window for that was extremely small. Something like two minutes (can't be bothered to look it up atm).

Next, they could abort to a sub-orbital trajectory and land in CA or FL.

Then there was ATO, and mission control would decide if they stayed in orbit or landed in CA or FL. IIRC this was used twice and they stayed in orbit both times at a slightly lower-than-intended orbit.

Re:It has to be proven better

[WindBourne]

No. the Shuttle did NOT kill 1 crew for every 10 missions. It killed 1 crew MEMBER for every 10 missions. It killed 2 crews.
BIG DIFFERENCE there.

Re:It has to be proven better

[phayes]

ONLY with pre-Block-5 COPVs and with the accelerated loading protocol which they abandoned after AMOS-6. Using the original & since AMOS-6, current loading protocols, there has never been a loading incident with the COPVs.

Re:It has to be proven better

[phayes]

Because it was sufficient to return to the previous loading protocols with which Space-X has NEVER had an issue with the pre-Block-5 COPVs..

Re:It has to be proven better

[phayes]

So using subcooled propellants and the slower loading protocol that Space-X went back to after ATMOS-6 that has never seen a loading incident is "throwing caution to the wind"?!?! Because nobody in 50 years ever used subcooled propellants?

But using solid boosters (which no-one in his right mind would use for manned missions), well that's not a problem for NASA (nor you visibly).

Forcing Space-X to fly Block-5 seven times to prove that it is reliable enough to used for manned Dragon-2, OK, But NASA can send it's first manned mission on SLS after only a _single_ test flight of the EUS without them "throwing caution to the winds"?!?!

"Maximizing safety" by forcing the frequently launching Space-X to jump through hoops but not applying the same criteria to NASA's & ULA's rare efforts is pure hypocrisy.

Re:Musk Doesn't Care About Risks

[Memnos]

Nice try, but I've already been tapped for the spot. They say my 3rd synthetic heart should still be doing okay around the expected time window. (My DNA, on the other hand, is fucked. Oh, and I'll be batshit senile.)

Evaluating safety

[sjbe]

While most people are not qualified to judge rocket safety risks, there is only one entity that has actually *demonstrated* that they are incompetent at judging rocket safety risks, and for that matter they did so spectacularly and totally, and then managed to stay in a position to continue judging rocket safety anyway and then did so again! That would of course be NASA

Eyeroll... If NASA isn't qualified to evaluate risks then nobody is. That's one of the dumbest arguments I've read in a long time. Yes NASA has made mistakes in the past. Good luck finding any organization that has not. Literally every space agency and private company building rockets has blown up rockets. SpaceX certainly has no track record to suggest they are better at evaluating risk than NASA is.

It's still a hell of a lot safer than the deathtrap shuttle was.

What is safer? A non-operational manned launch system? Pretty easy to have a perfect safety record when you don't launch anything. And by all means ignore the fact that SpaceX has a record of blowing up rockets at a rate pretty similar to the rate we lost space shuttles.

Re:Evaluating safety

[Gavagai80]

We only ever lost two space shuttles. The number or rockets SpaceX has lost is....a lot.

The number of Falcon 9s lost is also two, and one of those was lost in a static fire test that would never have had people on board. Not sure what universe you're living in.

Of course, the Columbia disaster wasn't an exploding rocket either. That disaster would have to be compared with a Dragon heat shield failure, which hasn't happened yet.

The shuttle boosters did have a better non-explosion rate than SpaceX, 134/135 compared to SpaceX's 52 out of 53 or 54 (depending whether you include a static fire test, which would be equivalent to a space shuttle exploding during testing with nobody aboard, which never happened probably because you couldn't do static test fires of a space shuttle). But your "a lot" of explosions are imaginary unless you're talking about initial Falcon 1 tests, which case you should be comparing with NASAs early test rockets which were famed for exploding frequently.

Reading comprehension failure

[sjbe]

I fail to see any difference between "load it up with propellant at super-cold temperatures to shrink its size" and "load it up with liquid hydrogen and liquid oxygen"

You fail because you cannot be bothered to actually read beyond the headline. The problem isn't THAT they are using cold propellant. The problem is WHEN they are loading the propellant. Handling fuel carries a non-zero chance of catastrophic failure. Fuel that is already on board has already been handled safely and is therefore safer to the astronauts. It's not clear if loading fuel after the astronauts are already on board presents an unacceptable increase in risk. It might or it might not. Historically the rockets have been loaded with fuel and then the astronauts board. SpaceX is proposing to change this.

Re:Reading comprehension failure

[jeff4747]

Except NASA also loaded fuel with the crew on-board. They just called it "topping off" - more fuel was pumped into the shuttle's tanks until liftoff, to make up for what was leaking out of the tanks.

Strawman

[sjbe]

You know, the solid-fuel booster rockets on the shuttle that cannot be shut down once started?

Exactly how many times was this a problem for the shuttle? Oh that's right, zero.

Von Braun, back in the 60s, already knew that you cannot really man-rate those things exactly because you have zero control over them once they went off.

Might have been true when he was alive. Demonstrable isn't true now since we have already man-rated them and flown large numbers of missions with them. The only problem we had with the boosters wasn't due to their performance or their ability to adjust throttle.

Re:Strawman

[Opportunist]

Exactly how many times was this a problem for the shuttle? Oh that's right, zero.

More often than you heard about it. Fortunately all but one of those cases turned out ok. I wish I could tell you more, but STS-51-L would have been an abort candidate about 20 seconds before the explosion. The problem was that there was no option for abort at this phase in the flight. All we could do was sit tight, bite our nails and hope, as usual. Went good a dozen times before, didn't work itself out this time.

There was no abort for any Shuttle flights from T0 to T120. Fly or blow. That there has been only one loss makes me almost believe that there is a god.

New procedure with known benefits and unknown risk

[sjbe]

Loading densified propellant is a known risk with calculated benefits.

Loading it with astronauts already on board is not a fully understood risk. Apples to oranges my friend. Might be a fine procedure but they are going to have to do the work of proving that it is safe. That's normal every time you do something different than the known and proven.

Re:New procedure with known benefits and unknown r

[religionofpeas]

Might be a fine procedure but they are going to have to do the work of proving that it is safe

Obviously. That's the standard procedure for all the risks involved with the rocket, and this has been well known to everybody involved since the beginning.

The alternative is more dangerous

[HangingChad]

The alternative to load and go is transporting the flight crew and personnel to the top of a rocket that's already fully fueled. Essentially personnel are working in areas with minimal protection and no ejection system standing next to a 230 foot tall bomb.

The way SpaceX does load and go, the flight crew is in a capsule with a functional abort system and the support personnel are a safe distance away.

Where would you rather be if there was an accident? In a crew capsule with an abort system or an elevator in the gantry? It's not rocket science...well, kinda is...but that's beside the point.

Re:The alternative is more dangerous

[ColdWetDog]

There is really only one way to test this. A fully loaded Falcon 9 Block 5 with an unmanned Dragon II capsule on the launch pad.

A little spark.

An earth-shattering kaboom.

And some cool video.

Come on, you want to do it, Elon.

Re:The alternative is more dangerous

[Strider-]

The alternative to load and go is transporting the flight crew and personnel to the top of a rocket that's already fully fueled. Essentially personnel are working in areas with minimal protection and no ejection system standing next to a 230 foot tall bomb.

And this is the crux of the debate. On the one side, as you point out, in a load and go situation such as SpaceX's current launch technique the technicians especially would not be in close proximity to a fully loaded rocket. However, once strapped in, the Astronauts in the capsule will be in close proximity to a rocket that is going through significant stresses and dynamic changes as it is loaded with fuel, cryogenic oxidizer, and pressurant. Yes, the dragon 2 has a pretty good escape mechanism, but a good conservative Engineer never bases safety calculations on emergency systems working.

The other (and traditional) option is to load propellants into the rocket first, let it go to steady state, then board it and go. In this case, yes you're exposing more people to a fueled rocket, but you're only doing so after the rocket has had time to settle.

So it really comes down to a risk calculation, what is more dangerous? Working around a fully fueled but reasonably stable rocket, or putting the rocket through potentially significant changes by loading it.

Re:The alternative is more dangerous

[chispito]

>Where would you rather be if there was an accident? In a crew capsule with an abort system or an elevator in the gantry? It's not rocket science...well, kinda is...but that's beside the point.

I would rather not be anywhere near the most likely accident, and by far the most likely accident is during fueling.

High risk != unnecessary risk

[sjbe]

Modern Human Space travel is almost always considered an unnecessary risk. With current technology the main reason for sending humans, is mostly for the marketing benefit, of letting us know that we can leave the planet if needed.

The main reason for sending humans into space right now is to explore. Marketing is a part of this to be sure but right now we're like the guy who has built his first couple of boats and is still learning how to sail with reasonable safety. We've barely gotten a few feet from shore. We barely know what is out there and we certainly don't have a robust vessel ready for long trips. The only way to get there is to send people into space accepting some amount of risk along the way. I disagree with this being termed unnecessary risk. Unnecessary risk is risks that you can strip out of an activity but choose not to. Not launching people into space carries risks too so it doesn't make sense to call all manned space travel unnecessarily risky.

That said I do support man space flight. To the Moon and Mars.Knowing that it is a high risk activity. But I see it important for our survival is to expand to new areas.

Yes it is high risk. High risk does not mean one should ignore unnecessary risks along the way. Only a fool takes a high risk activity and makes it needlessly riskier. I suspect at the end of the day SpaceX will prove this procedure is fine. After all it's not like we've been blowing up rockets on the launch pad while fueling them. But it is different and anything different needs to be evaluated carefully.

This smells like a hit piece

[Mysticalfruit]

Yes, there are valid concerns regarding densified propellants. Can those be mitigated, to a degree. SpaceX has now multiple years of handling densified propellants... However, just stating that they've done it a certain way because, well they've done it a certain way.

Let's think this out.

Scenario 1. Vehicle is dry. Astronauts and Techs ride up the elevator and get Astronauts situated the vehicle. Technicians then leave the pad. Abort system is verified and enabled. Propellant loading begins.

Scenario 2. Vehicle is loaded and oxidizer boil off is occuring, which means the Astronauts and support staff will be riding up an elevator next to a loaded rocket, plus the strong back will have be supplementing the vehicle so it's going to have a substantial amount of cryogenically cooled oxygen in it as well. Now, once the crew is loaded, the technicians need to safely get down the elevator and away while boil off and supplemental loading is occuring

Which of these scenarios seem more likely to be a recipe for disaster?

I called this a hit piece because this is looks from the outside like SpaceX is being forced to jump over much higher hurdles than ULA.

Re:This smells like a hit piece

[gweihir]

Indeed. The writer uses simplification so gross that all conclusions drawn from it are basically invalid.

Re:This smells like a hit piece

[RKThoadan]

I would never rely on a layman's estimate of risk. NASA says that Propellant loading is the most dangerous pre-launch activity and in this case I'm going to trust them. SpaceX isn't denying that it's dangerous, just that they've managed the risk well enough. I'm thinking that they probably have, but I'm not particularly qualified to make that judgement so I hope they don't consult me on it.

I note that you give a rather detailed list of all the activity happening in scenario 2, but just say "Propellant loading begins" in scenario 1. If I were to similarly manipulate the amount of details provided I could probably make tying my shoes sound more dangerous than a NASCAR race.

Re:This smells like a hit piece

[Mysticalfruit]

I hope they never call me to help them assess risk. You bring up a good point... the "Propellant loading begins" I should have bracketed because it's a whole set of steps, some of which results in oxidizer being vented. Purging nitrogen, loading helium, loading crypo RP-1, loading cryo oxygen, etc.

Now from a layman's point of view to me it seems much more dangerous to have people and equipment all over the scaffolding while the vehicle is venting oxidizer.

Since we're arguing this whole process is dangerous... Let's limit the number of people in danger... The people in the DragonRider capsule have a means to get the hell out of Dodge if shit goes wrong... the poor saps on the crew access gantry are simply fucked.

Re:This smells like a hit piece

[DerekLyons]

Let's think this out.

Yes, let's think this out. Let's work forward from the evidence rather than (as you did) backwards from a conclusion.

Which of these scenarios seem more likely to be a recipe for disaster?

Let's compare the scenarios:

Scenario 1: Vehicle is will not remain in a stable state between boarding and launch. It will transition between the unfueled and fueled states.

Scenario 2: Vehicle will remain in a stable state between boarding and launch.

From where I sit, actually looking at the facts leads me to believe that scenario 1 is the more dangerous. Further support comes from simply examining the record - in the long history of launching manned vehicles fueled the normal way there have been precisely zero losses related to the fueling process. In the short history of handling densified propellants, there's already been one loss related to the fueling process.

Re:You're Closer Than You Think

[K. S. Kyosuke]

Actually, they're largely enabled by sane engineering design decisions, such as not manufacturing multiple kinds of tanks (diameter, material, etc.) for a single vehicle, not manufacturing multiple vastly different kinds of engines, and so on.

To be fair to NASA

[MrKaos]

IIRC, the US Nuclear sub command criticized NASA in the Columbia Accident Investigation Board's report for claiming who else operates high performance machinery in hostile conditions?.

They replied We do, we operate Nuclear Submarines and put five thousand people to work studying the Challenger accident to see what we could learn, how many did you put on it?

I personally don't think it's fair to blame NASA for being safety conscious after blaming them for not being safety conscious.

Re:To be fair to NASA

[MrKaos]

It's not a question of being 'safety conscious'. NASA has been 'safety conscious' it is about how they apply this principle. They were safety conscious with the Shuttle program too, they simply failed to follow 'good engineering practices'

Well No. The problem with the Shuttle was it was well engineered with a fundamental design flaw in the launch configuration. That guaranteed ice strikes onto the re-entry tiles which NASA referred to as 'in-family' which the same command criticized as "converting a knowledge of failure into a knowledge of success".

Space travel is dangerous

[gweihir]

Anybody that thinks this can be made totally safe is just stupid at this time. Maybe it will eventually get down to the risk of air travel, but that will take a few decades.

Re:Space travel is dangerous

[iggymanz]

space travel can never be at the level of risk of air travel. Random rocks of all sizes hitting you at tens of thousands of kilometers per hour, high radiation, need to regenerate or create atmosphere, loss or irregularity of propulsion causing one to drift or be lost forever or burn up...there is no comparison to travel by aircraft

Re:Space travel is dangerous

[gweihir]

Oh? You seem to be unaware of all the bad things that can happen to airplanes.

Re:Space travel is dangerous

[iggymanz]

did you flunk math? 5% mortality rate

Re:I know being a pussy is en vogue nowadays,

[gweihir]

Very true. The fascinating thing is, however, how much Generation P actually fails at risk management by vastly overestimating some risks and vastly underestimating others.

Manned flight protocol

[Immerman]

Easy solution: pre-load a lower amount of fuel on manned flights.

The F9 has payload capacity to burn, the last-minute fueling boosts that even further. You want more safety, load the fuel beforehand, and accept the resulting lower capacity, which should still be more than enough to transport a few passengers to orbit.

Temperature difference

[DrYak]

I fail to see any difference between "load it up with propellant at super-cold temperatures to shrink its size" and "load it up with liquid hydrogen and liquid oxygen", where, as far as I know, manned rockets have been loaded that way since the Apollo missions.

Think liquid mercury changing density (and thus size occupied in the thermometer's tube) depending on the temperature.

Since the Apollo missions, liquid hydrogen and liquid oxygen are made liquid by cooling them just barely enough to make them liquid, just below their freezing point.
The big advantage is that, even if it's cooling, it's not cooling *that* much. The rocket can then basically stay waiting for some time (well a tiny bit is going to boil of, but you can top that tiny bit at the last moment, by adding more liquid).

The SpaceX way is to cool the liquid *much further*. You're not just cooling them "a bit" to make them liquid, you cool them as much as physically possible in your system.
Because you cool them to much colder temperature, they are much dense. You can fit much more such super-cooled fuel in the same tank than if it were merely "chilled enough to be liquid" fuel.
The draw back is that once loaded, you have to take off as fast as possible. Otherwise you'll eventually loose any advantage of your super-cooled/super-dense fuel as the temperature will eventually rise (less dense fuel : suddenly occupies at lot more space. It will either flow out, boil out, or you'll bust the tank if there's no way to get of the sudden extra volume).
You could top up any boiled-off fuel at the last moment, but you cannot regain any of the higher-density unless you magically re-cool the whole tank's worth of fuel.

In NASA's experience, the most dangerous moment is the moment you're loading the fuel in.

- With the Appollo style, the point is to do the dangerous fueling first, when there's nobody in the dangerzone around the rocket.
Only then, once the dangerous phase is over and the whole thing is a bit more secure now, you take the necessary time to load your payload (passengers here).
Then top-up the boiled-off and go.

- With SpaceX, the payload need to be loaded first (the astronauts needs to be already in the capsule), because you can't afford much wait time between the fuel loading and the take off (remember, the more time pass, the more the temperature rises, the less super-cooled/denser you fuel is).
So during the most dangerous phase, during the fueling there are already people (the astronauts) in place.
SpaceX's mitigation is that by that time, they are already well installed in the capsule, so the capsule should be able to evacuate them to safety if anything goes wrong.
NASA's opinion is that this is unnecessary risk taking just to shave off a few more fuel by having it at a lower-than-apollo temperature.

Re:Temperature difference

[kellymcdonald78]

One could also argue that the new approach is safer for astronauts and support crews Operations during fueling may be more dangerous, however astronauts are boarding and getting strapped into a known safe vehicle (there is no fuel or oxidizer when they board). When the fueling takes place they the capsule is ready to escape at a moments notice. No other people are put at risk. There is a contingency if something goes wrong. Or, while operations while fueled may be less dangerous, astronauts and support crews are working on a known dangerous vehicle (fuel and oxidizer onboard with ongoing top up procedures). Everyone is at risk during the boarding process and there is very little contingency if something goes wrong (the zip line option only works in a very limited set of circumstances) Until the detailed analysis is done, we don't know which is safer

Re:Temperature difference

[TheDarkMaster]

Thanks, your reply is much more useful than the reply of that "sjbe" moron.

Re:Temperature difference

[TheDarkMaster]

I was thinking the same thing after remembering how the dragon's escape system works

Re:Temperature difference

[jeff4747]

Except NASA pumped fuel into the Shuttle's external tank until right before launch. The liquid hydrogen line was the last thing to disconnect before launch because they were pumping fuel into the tank until right before the SRB's lit.

One could argue that this "topping off" was safer than SpaceX's fueling, but we'd have to actually study them to know.

Frequency

[DrYak]

NASA's big argument is that the former (rocket goes boom while fuel-loading) is much more likely than the later (a rocket that has proven to go boom during/immediately after fueling suddenly goes boom at a later point in time, while the astronauts are on their way, but not already installed into something that can serve as an emergency escape) - ie: fueling in particular is making them extremely nervous compared to any other step.

SpaceX' argument is that the escape mecanism is good enough to make the actual impact of a boom-during-fuelling negligible - ie they have quite some crazy trust into their capsule's escaping performance.

Re:Before NASAexisted Korolev already codified saf

[ColdWetDog]

And Korlov pulled those restraints out of his (rather experienced) butt. They were gut checks. There was no science or engineering behind them. And that was almost 70 years ago.

Things change. Knowledge advances.

This isn't to say that SpaceX isn't taking additional, unnecessary risks, but to run back to this bit of ancient received wisdom is hardly helpul.

Re:Musk Doesn't Care About Risks

[Kozar_The_Malignant]

>Oh, and I'll be batshit senile.

That's never been a bar to being president, emperor, dear leader, or anything else.

This is an Engineering Problem

[LifesABeach]

Musk, your H1B zombies cannot solve it? H1B's can use each other for testing, which means a trip to the U.S. and maybe space?

Re: This is an Engineering Problem

[oobayly]

What H1B holders work in SpaceX? ITAR requires that anyone who works on launch systems (due to the similarity to ICBM systems) to be a US citizen or green card holder.

Re:This is an Engineering Problem

[kellymcdonald78]

Except that only US citizens can work at SpaceX due to ITAR restrictions (unless you go through an incredibly extensive waiver process)

Re: You're Closer Than You Think

[Type44Q]

Sorry, shill; your employers will never be able to compete with Musk (nor even comprehend why) this sort of confusion often arrises when typical 'Wall Street/MBA' and/or 'Southern Frat Boy/retired AF Officer' personality types (with median IQ's no higher than a buck-fifteen or so) run up against a spastic nerd with some real brains, like Musk. Poor, dumb ULA fuckers; they still haven't figured out what's hit 'em...

Is there....

[Heebie]

Is there a rocket that DOESN'T put anyone/anything at risk? There were a lot of safeguards in-place before the Challenger disaster. A chunk of stuff flying off damaged the Columbia to the point where it disintegrated on re-entry. Of course there's some risk. The question is are they doing enough to mitigate that risk, not whether or not it's there. That's something that would be good to see an article on.. exactly what is SpaceX doing to mitigate the risks of fueling their rockets this way?

safety vs. money

[superdave80]

"NASA is supposed to be a risk-taking organization,"

Yeah, but....

...they load it up with propellant at super-cold temperatures to shrink its size, allowing them to pack more of it into the tanks.

Taking risks just so you can save some money by making smaller tanks is an unnecessary risk.

Re: Just give fire arms to everyone!

[joao.cordeiro]

So, when Trump says it it's a good idea,when I say it, I'm a troll?

Risk depends...

[SuperDre]

Well, it all depends on how solid the crew compartment is. If it can withstand an explosion due to this and it can make sure the astronauts wouldn't be (badly) hurt, then there's no reason not to use this. But if the crew compartment cannot withstand it, well then it's not even a question if it should be used.. Just make sure the crew compartment can withstand the explosion for the astronauts to survive..

Re:Risk depends...

[jeff4747]

Well, it all depends on how solid the crew compartment is

It's not possible to build a crew compartment strong enough to withstand such an explosion that is still light enough to be launched into space. So they don't.

Instead, the crew capsule has emergency rockets that launch it away from the explosion, and then land the capsule using it's normal parachute landing systems. Just like the 1960's NASA rockets.

Re:Musk Doesn't Care About Risks

[torkus]

If you had a 50/50 chance of death you'd still have a long line of highly skilled and motivated people ready to jump at the chance.

ULA can't compete so it lobbies and propagandizes

[Jerry]

The Air Force released a report that computed the costs for 66 ULA launches for Air Force from 2016 to 2022. They averaged out at $322 million per launch. SpaceX average launch costs are between $62 and $95 million. Besides using the Russian RD-180 as its first stage engine, it can't compete by throwing away that engine and first stage after each launch. The ULA is supposedly negotiating with Bezos to use his main rocket engine.

The ULA's launch of the Mars InSight Lander was classic 1960 launch techniques. At T -3 we heard "Range Safety? Go. Guidence? Go. ..." for what seemed like forever. A bunch of old men watching monitors. Someone forgot to put up the performance figures until after MECO. When the lander was ejected towards Mars they all stood up and shook each other's hands, except when they saw female staff ... they hugged them.

At SpaceX most of the engineers are all young and wearing Gap. They cheer at each event .... launch, MECO, SSE, re-entry burn, landing burn and landing, SSCO, satellite ejection. Every event gets cheers and claps. It's a pleasure to watch people enjoy their work.

ULA has begun a propaganda and lobbying campaign to counter SpaceX's innovation and performance.

Re:You're Closer Than You Think

[WindBourne]

yeah, that is why the DOD and NASA LOVE SpaceX and the prices that they charge. In addition, the safety record is actually decent on the F9. They have had 1 failed launch, and 1 failed payload (due to NASA's rules) in 53 launches. Likewise, no failures on FH, though first launch.

And that is a none-issue now

[WindBourne]

The H2 tank was redesigned to stop that leakage (I think a metal coating was added, though not certain ). As such, none-issue.

Pot, kettle, black..

[h8sg8s]

This is a Washington Post drive by of SpaceX because Bezos (owner of WaPo) has orbit envy. BTW, NASA has launched numerous manned missions under questionable safety issues (Challenger, Columbia) and will man-rate SpaceX as soon as the F9 block V has flown the requisite number of times without incident.

Humanity Exploring

[Doctrinsograce]

If guarantee is required that no lives be lost, human beings wouldn't cross the street, let alone explore. Oy vey!