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Does SpaceX have the capability to send people around the moon? originally appeared on Quora: the place to gain and share knowledge, empowering people to learn from others and better understand the world.
Answer by Robert Walker, space writer, on Quora:
I think the chances of the SpaceX mission around the Moon going ahead on schedule in 2018 is tiny. But on the remote chance it does happen, I would not fly on that mission, if you paid me a billion dollars. The problem is that they have to rely on hardware that is hardly tested in space at all. They are depending on a spacecraft which will have its first flight in 2018, the Dragon 2. Their current Dragon is only rated for re-entry from LEO (Low Earth Orbit). Only the Dragon 2 has a thick enough aeroshell to handle the much higher speed of re-entry into the Earth’s atmosphere from the Moon.
Also, the Falcon 9 “full thrust” can launch a Dragon 2 to LEO but not around the Moon. So they are also depending on the Falcon Heavy to launch it, a rocket that will fly for the first time perhaps in late 2017. So it would be one of the early flights of a Dragon 2 (manned or unmanned) and the first crewed flight on a Falcon Heavy, and one of its first flights ever of this rocket, if they do it on that timetable. Also, they would have had their first ever crewed flight into space, earlier the same year.
Their unmanned rockets have blown up once each year for the last two years (Sept 1, 2016 and June 28, 2015). If one of the early flights of the Falcon Heavy blows up, then that will delay things a lot and surely lead to questions of passenger safety.
They are also using a fueling procedure where they load the fuel after the astronauts are on board - something never done before with passengers, and there is some concern that it is less safe. The rocket can explode while the fuel is being loaded, and that’s what happened to one of their rockets last year (the explosion on Sept 1, 2016). If the fuel is already on board before the passengers, you have removed one of the risks that could happen. The passengers might be able to escape if the rocket explodes on the launchpad with them on board. SpaceX has a system that should do that, which also should be triggered automatically in the case of an explosion like that - but it is itself one more thing that could go wrong, and so far never tested with humans on board. If the first crewed flight to the ISS blows up, even if the crew survives in the escape capsule, that would surely again lead to questions of passenger safety and delay things.
This is an essential part of their rocket design because they use fuel that has to be kept very cold (to increase its density for a higher performance). They can’t keep the fuel this cold for long after it is loaded. This makes it impossible to load the fuel hours in advance before the crew.
But if neither of those things happen, it doesn't show that it is safe. As Richard Feynmann wrote about the Challenger disaster:
"The argument that the same risk was flown before without failure is often accepted as an argument for the safety of accepting it again. Because of this, obvious weaknesses are accepted again and again, sometimes without a sufficiently serious attempt to remedy them..."
In this case, loading the fuel after the passengers seems like a risky approach, and perhaps his remark is therefore relevant to it. Even if they get several launches without incident using this procedure, it doesn't prove that it is now safe. The FAA needs to keep a careful eye on this just as it should have done with Challenger.
They are also depending on a life support system working for a week in space which has only ever been tested for that long on the ground. And there is no way to abort the mission back to Earth. This is the worst thing about it for me. If they have an Apollo 13 style failure of life support on the way out, then they will have to make do with whatever they have in their spaceship to try to fix it. SpaceX has had issues with quality control of their parts, so I think it’s not impossible that a vital part of their life support system fails in some way. If the carbon dioxide scrubbers stop working, for instance, the carbon dioxide build up would kill the crew on those time scales. Apollo 13 were able to use the attached lunar module as a “lifeboat”, but they will have no lifeboat.
There is no problem with life support going wrong in LEO, not minor things like the CO₂ scrubbers not working, as you can just abort back to Earth within a few hours of noticing the problem. But on this mission it could easily be several days before you can return. Such a tragedy would unfold very slowly. And there would be absolutely nothing that anyone on Earth could do about it except give them advice.
If they do this, I wouldn’t fly on it if you paid me a billion dollars for the ride. But I expect it will be delayed and delayed, as happens so often with SpaceX.
Also the FAA will need to approve it for safety, and it doesn’t seem very safe, at least, not as they have outlined it. I don’t think it is “bluffing” but it is hugely optimistic, that they will be able to achieve so many ground breaking innovations so quickly, and that nothing will go wrong with any of them, and that they will all be completed on timetable and be passed as safe for flight. They often claim that they will be able to do things many years before they actually do. For instance, they claimed the Falcon Heavy would be ready some years ago (first they said 2011, then late 2013 to 2014) and it is still not ready.
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