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

[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

[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

[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.

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.

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...

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.

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.

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

[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.

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.

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.

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.