Originally Posted by
cavuman1
Yes, WillowRun 6-3, I am thinking of both the Starliner and the Orion spacecraft. Neither have lengthy proven histories and both have had demonstrable glitches. They do not approach Mr. Musk's Falcon/Dragon combination for flight frequency, safety, and reuseability. I understand your differentiation of destination, be it LEO, ISS, Moon, or Mars. All require a lot of thrust to get there, parachutes to return, and amazing engineering the whole way. I am concerned that the admixture of "Big Gummint" and Corporate Bureaucracy may be an equation which compromises safety. One need not look further than Challenger and Columbia to see my point, which I believe to be entirely relevant.
- Ed
As a relatively minor point regarding Orion, Northrop Grumman as a prime contractor has not been tarred and feathered the way Boeing has been dinged (MAX, door plug unplugging). Even though Boeing had legacy credibility from Apollo, it lost its way - but the Grumman heritage at NG . . . LM, TELMU and all that. I have more faith . . . but then I can tell you exactly where I was when the news came over the radio about the Apollo 1 pad fire (I was 14 at the time) so, no claim to complete objectivity.
As to the technical matters with regard to the Orion heat shield, I did not save the citation to the article but only a few weeks ago I read an article which reported on the extensive discussions offered by two participants in the safety review, one an internal expert and the other essentially an outsider. At the risk of omitting something important from the article, the two participants discussed that the material of the heat shield had experienced outgassing, and the extent or duration (or both) of this process had not been completely anticipated by NASA or the manufacturer. Also iirc, the plan for Artemis II is to fly (as noted by others) a different re-entry trajectory rather than redesign the heat shield - although (again iirc) this is being done for Artemis III.
Somewhat relatedly to all the above about Orion, it is fine to point out that it has no established track record, and then point to Dragon which does. But Dragon was able to build upon the successes of the human spaceflight program in a way that does not apply to deep space missions (isn't the velocity at which the lunar missions return to Earth much higher than deorbit from LEO? - and isn't the Orion spacecraft a much heavier spacecraft? - and a more complex one, given its deep space mission requirements?) ((And I don't have much to say about Starliner, other than NASA made the right decision not to risk bringing Butch and Sunni home in it.))
There is one other point about SpaceX flight hardware and its overall program that I believe is important to at least try to articulate. On one hand, starting with the troubled legacy of Dr. Von Braun through which the United States embarked on the technology and engineering initiative which culminated not only in the successful Apollo lunar landings but also in U.S. preeminence in space programs and technology, the United States space efforts have always been an expression of national will and purpose, decided upon and endorsed by the body politic. (That is, even though to imagine the Congress and successive White House administrations as "bodies", politic or otherwise, is more than slightly gross.)
On the other hand, SpaceX carries the decisions and endorsement almost exclusively of only one individual person. No question, no dispute, that SpaceX's conquering of reusability of space launch vehicles is a testament to several things - to the free enterprise system, to the ingenuity and "it" factor of the individual whose vision became the reality, and to some extent, even to a modest flexibility of the NASA bureaucracy. But carrying the flag, being appointed as "the United States" in the space hardware domain, should require something more than success in efforts so far. And I'll give a timely and concrete example.
The design of the HLS (Starship as a lunar landing spacecraft) requires orbital fuel depots and several transfers of cryogenic propellant. In the Apollo program (and Mercury and Gemini before) the engineering and technology risks were carried by the institutions and program elements across the country, in industry, government (not only NASA), academia. The story of how the LRV was designed and how that design was made to fit into the LM is a good example but far from the only one. Today, the big hurdle is cryogenic propellant management on orbit, in the depots and the transfers. Is this something that the United States national interest in space programs and technology should allow to be essentially contracted out? And in considering an answer, it might be useful also to consider, "Cryogenic propellant management in space: open challenges and perspectives", A. Simonini (et al.) npj microgravity (2024 10:34). (As a caveat to the foregoing, of course NASA is quite involved in the cryogenic propellant work being conducted by SpaceX. The difference is that if the legacy space model did not deliver the correct engineering and technology, by definition the voting public could exact political accountability. Though there could be something like accountability if and when the single most important engineering and technology risk is not addressed successfully by a private sector hardware provider, it would be significantly less than in the legacy model, if it even would be accountability at all.)
Edit; how the LRV was designed and made to fit into LM.