It's also untrue, US rocketry kept varied propulsion types throughout its history including both RP1-only and LH2-only as well as mixed stages, HTPB and Aerozine. Your painting of rocket scientists as some sort of confederacy of dunce unable to get a grip on tradeoffs is not only inane it's insulting bullshit.
Everyone who grew up idolizing rocket scientists should read it. If you have problems with missing pages or broken figures, try a different PDF viewer. The PDF has something odd about it that confuses some in-browser viewers.
My account was simplified, but the tangent was long enough already. It's true that in the early days of US rocketry (through the 1960s), there were a large variety of propulsion types that were experimented and deployed. The stasis didn't really set in until the 1970s.
Since then, it's also true that solids and hypergolics continued to have a role, both as strap-on boosters (because gravity losses) and in military systems (and their derivatives) where cryogenic liquids aren't advisable. (The military was always more whole-systems and pragmatic about their approach to rocketry.) Finally, it's also true that non-LH2 legacy rockets (and their closely-related derivatives) continued to fly (because switching costs).
However: in civilian rocketry (eg. NASA), as far as new developments were concerned, the picture is as I described. I was peripherally involved in that scene during the 1990s and had many people at NASA and LockMart tell me personally, quite explicitly, that specific impulse was very nearly the sole determinant of rocketry, and that therefore no fuel other than LH2 would ever be considered. Feel free to look at the kind of arguments cited during the fuel-density wars on sci.space.policy if you want a feeling for the kind of vehemence with which this opinion was expressed.
So, yes, I stand by my story. From the mid-1970s through the mid-2000s, US rocketry development was wholly paralysed, due in very large part to these kind of attitudes and overly-narrow optimisations. As evidence, I present the NASP, X33, and SLI, amongst dozens of smaller, equally failed initiatives. Feel free to counter with some examples of successful new rockets (as opposed to derivatives like the Pegasus, Taurus, and Delta III) developed during that period. The only examples you'll be able to find are Delta-IV -- which switched to LH2 at frankly mind-blowing expense, has had an uninspiring career, and is about to be axed -- and the Atlas V -- which gave up and just bought LOX/RP1 engines from Russia, since the US had lost the expertise to develop decent LOX/RP1 engines itself.
I'm not saying that the US civilian aerospace industry was a confederacy of dunces, just that for 30+ years it had the productive output of one. It was certainly well-supplied with smart people, but yes they were absolutely unable to get a grip on tradeoffs, and it showed.
> is not only inane it's insulting bullshit.
You've got a lot of HN Karma, but you haven't yet learned that people here prefer evidence-backed arguments to ad-hominem attacks?
At the time, however, I recall hearing endless griping from various corners that NASA had the gall to fund a non-LH2 engine. Internally, this was justified as being nothing more than a cheap and cheerful way to get the X-34 to its flight regime -- definitely not a serious rocket engine, no sir! That was LH2's job! Everyone knew that!
The support of the RP1 rebels within NASA wasn't enough to keep it alive, and the program was cancelled after a few years. Later, it was resurrected as the template for SpaceX's first generation engines. So I personally consider this to be the exception that proves the rule.
Your evidence is:
>I was peripherally involved in that scene during the 1990s and had many people at NASA and LockMart tell me personally, quite explicitly, that specific impulse was very nearly the sole determinant of rocketry... Feel free to look at the kind of arguments cited during the fuel-density wars on sci.space.policy if you want a feeling for the kind of vehemence with which this opinion was expressed.
Your entire point is based on bulletin board discussions and anecdotal evidence from being peripherally involved with rocketry in the 90s (which given context, I'm taking to mean "I hung out in space forums and bulletin boards and talked with people who claimed to be rocket engineers.")
I enjoyed reading both of your posts about this (with a grain of salt), but it's a bit silly to call someone out for lack of evidence after writing several hundred words without a single piece of hard evidence supporting it.
Oh for fuck's sake. I don't like arguments from authority, but if you really want one: yes, I hung out on internet space forums in the 90s and am thus aware of their contents. But I also was a member of the Space Access Society and regular attendee of its conferences; an organiser for the National Space Society and regular attendee of its conferences; and an organiser and founding member of the Mars Society and regular attendee of its conferences. In this context, I was personally well-acquainted with folks like Gary Hudson, Robert Zubrin, and Buzz Aldrin, as well as innumerable lesser-known individuals from NASA, Boeing/Lockmart, and the various alt.space renegades. The stories I tell come directly from my contacts with them.
Furthermore, the "evidence" I provided was citations of the NASP[1], the X-33[2], and the SLI[3]. The first two represented NASA's flagship attempts to develop new space-launch systems during 80s and 90s; they failed due to weight growth and integration problems stemming from over-optimisation of the (LH2) propulsion system at the expense of all the rest of the vehicle's systems. By the time of the SLI in 2000, RP1 was starting to find a (small) place at the table again, but the program still failed due to too narrow a focus on propulsion optimisations. I figured that anybody familiar with the space industry (as the person I was replying to seemed to be) should be familiar with these failures and their underlying causes; they are not exactly secrets.
1: https://en.wikipedia.org/wiki/Rockwell_X-30
I'm absolutely certain that Masklinn did not assert that the optimal design was used every time or that NKoren's comment was completely lacking any accurate information. Neither of these assertions needs to be made to dispute the central idea that US rocket scientists are too incompetent to even consider alternative fuels or broader design tradeoffs.