Neil_F wrote:
One thing of note on Starship is that it is NOT man-rated. One only has to look at how long the process took for both Boeing and SpaceX on their capsules to understand the impracticality of man-rating Starship in a short timeline.
True, but the Artemis project has tied itself to Starship’s timeline for achieving human rating, because that’s how they’re getting to the surface. So there is no plan for getting people onto the Moon’s surface without Starship. At that point there’s no raison d’être for Orion, and in fact it makes the mission much more expensive and complicated.
I have not seen anything on Starship about launch abort systems so I would be surprised if it gets man-rated (at least for launch) within the next 3-4 years. Man-rated Earth landing – what’s the engine-out capabilities? Given that Starship is a powered lander losing an/the engine during the later stages of descent would be “problematic” in the extreme.
Now you would be right in pointing out that this same issue applies to landing on the moon as well. Maybe the mass/gravity/number of running engines/throttleability (rocket engines only have a limited capability to throttle) combination is better. This, I admit, is something that i have not looked into.
You are correct that the USA have (currently) wedded themselves to Starship for lunar landing. This doesn’t mean that this is what will happen (NASA are/wrere being challenged by the “losing” bidders that they had moved the goal posts for SpaceX) or even that someone else (Chinese?) will not be the next to land people on the moon.
As you may gather I’m not a huge Spacex fan. I’m sure they will get there eventually but their timescales are all PR and no reality.
I’m also not a great fan of Orion. It works for a few launches (use up those surplus Shuttle engines) but hugely expensive once these are gone.
Neil_F wrote:
As you may gather I’m not a huge Spacex fan. I’m sure they will get there eventually but their timescales are all PR and no reality.
True about their timescales, and Elon’s timescales in general. However they have achieved something quite remarkable in being able to consistently launch and recover their spacecraft. That is a prerequisite for any kind of real permanent presence in space (that goes beyond a small laboratory), and something no one else has managed to do thus far.
Musk has pulled off a lot of clever stuff, but he’s still a comedian. I cannot see how anybody can take him seriously.
Buying a car, ok… the downside is limited.
Peter wrote:
Musk has pulled off a lot of clever stuff, but he’s still a comedian. I cannot see how anybody can take him seriously.
I’m no fan of him as a person, but to me the SpaceX results speak for themselves. If you compare them to any of the other competitors in the space (Virgin, Blue Origin, Boeing, etc.), they have actually delivered with serious new spaceflight capabilities. Virgin and Blue Origin are the gimmicks at this point. I’m a big Rutan fan and really thought he would be the one doing what Musk has done, but SpaceX is the real deal whether you like Musk or not. He’s also managed to attract most of the really talented people in the industry, so it’s no wonder.
Sure, although those people can’t get interesting work anywhere else, so all the time he is throwing billions around, they will be keen to work for him. In industry you tend to not get a chance to do something wildly new.
To do a Moon programme, never mind a Mars programme, you need a lot of staying power. Not sure NASA has got it either (the USSR-USA race largely drove the last one) but I would be amazed if Musk will hang in there for long enough. He spends half his waking hours on crap like buying twitter, and then not buying twitter because, he says, it is stuffed with fake accounts. Well, no sh*t Sherlock, anybody could have told him that. About 1/3 of EuroGA joinups are fakes/spammers/etc. Got two just today.
Can’t NASA build more of the shuttle engines?
Peter wrote:
He spends half his waking hours on crap like buying twitter, and then not buying twitter because, he says, it is stuffed with fake accounts.
Very true. Hopefully he’s created enough of a flywheel in SpaceX that it sustains itself in spite of him. And hopefully others will catch up so it’s not all on them.
I am sure this has been calculated, but I am amazed you can fly to the moon from earth orbit, land there, take off, and fly back again to earth orbit.
The chemical (fuel) problem has not changed since 1960s (or ever). It was worked out back then that to do this all the way from the earth you would need an impossibly massive rocket, so this method is a halfway point. Maybe it is possible.
But last time I read this in detail, NASA was going to do the same approach as in Apollo. Just a lot bigger/spacious. It is the most logical and the most efficient. There is also a reason why all the astronauts came back: the hardware was quite simple. Yes, the LM had just one engine, but NASA tested it in a vacuum chamber, to make sure it started x hundred times. The fuel feed was from tanks pressurised by helium, IIRC. No pumps needed. And a fair bit of manually selectable duplication. Musk’s proposed tall 1930s-sci-fi-like landing rocket would be hugely more complex.
This is a great thread.
Whilst I also do not think much of Elon Musk ad a person, he is a visionary. Sometimes (in fact often) the vision does not work out. When that happens it usually creates a lot of “I said that would never work” comments.
I agree, but if you splash enough billions around, almost anything is possible. Bezos blew 38BN $ on a divorce but he will still eat tomorrow 
I would (almost) never say something is impossible. This is just a complex system design job. It is obviously possible to make a rocket which returns and lands vertically; NASA have been doing that kind of stuff for decades, e.g. landing stuff on Mars recently, with thrusters, and the right way up. Even Apollo was capable of a full autoland, although none of the flights actually used it (it could not avoid rocks, etc) and that was done with a computer running at 2.048MHz. It just has not been done on the earth, because there is no way to return to the earth without a lot of heat (well, there is, at a huge fuel cost, and a heat shield is a lot cheaper).
