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Congress and the Nixon administration trapped NASA in LEO. There was extensive planning inside NASA for applications of Saturn-Apollo technologies [0]. Two of t

Congress and the Nixon administration trapped NASA in LEO. There was extensive planning inside NASA for applications of Saturn-Apollo technologies [0]. Two of the ambitious ones were a manned Venus flyby [1] and a permanent Lunar base [2]. After the Apollo I fire Congress lost its appetite for space and slashed NASA's budget [3]. The Nixon administration went all-in on the Space Shuttle which ate up all of NASA's manned spaceflight budget. Skylab and the Apollo-Soyuz Test Project were the only AAP projects to survive and only at the cost of Apollo missions 18-20. The Saturn-Apollo program had a super-heavy lift rocket (Saturn V), a man-rated heavy lift rocket (Saturn IB), a Lunar trajectory capable command and service module, a lunar lander, and a workable wet workshop space station (Skylab). Congress tossed all of that away. The Space Shuttle program wasn't a bad idea, a heavy lift vehicle that provided a shirt sleeve environment but could support EVA is actually an awesome thing for LEO. But Congress scrapping Saturn-Apollo trapped NASA in LEO because the Shuttle was only capable of LEO. It's not a platform that can support manned Moon missions let alone any more distant bodies. [0] https://en.m.wikipedia.org/wiki/Apollo_Applications_Program https://en.m.wikipedia.org/wiki/Apollo_Applications_Program [1] https://en.m.wikipedia.org/wiki/Manned_Venus_flyby https://en.m.wikipedia.org/wiki/Manned_Venus_flyby [2] https://www.wired.com/2013/11/moonbase-apollo-1968/ https://www.wired.com/2013/11/moonbase-apollo-1968/ [3] https://www.wired.com/2012/08/before-the-fire/ https://www.wired.com/2012/08/before-the-fire/

akiselev 6y ago
Not only that, but the nuclear rocketry program for Mars was making breakthroughs like the nuclear lightbulb hybrid reactor & closed loop rocket engine [1] - that the public wouldn't see until declassified papers hit JPL's archives in the 2000s. This program was cancelled by Nixon, setting us back at least half a century. [1] https://ntrs.nasa.gov/citations/19730003970 https://ntrs.nasa.gov/citations/19730003970
- pfdietz 6y ago
  Not really a setback, because there was no place for that technology. Lack of space reactors wasn't and isn't a roadblock. Had that development continued it would have been largely wasted, and the knowledge gained would have decayed away.
  - akiselev 6y ago
    It easily functions as a self-breeding terrestrial reactor that reaches criticality with 1/500th to 1/1000th the fuel of existing nuclear reactors (~20kg). The design requires active power that shuts down the reactor on failure, making any accident a complete nonevent. It can even be kickstarted without huge amounts of enriched fuel with the addition of a neutron gun (which they used to test the design without nuclear fuel). The core infrastructure required to support such a reactor are also covered by far less red tape (mostly centrifuges). It would have changed the face of power generation at a critical time for climate change if it was allowed to reach fruition. Instead it was locked away in UTC & NASA archives.
    - pfdietz 6y ago
      The requirements for a space reactor, and for a terrestrial reactor, are radically different. No space reactor will make sense for terrestrial power generation. The temperatures are different, power density is different, safety cases are different. A 20kg reactor likely needs highly enriched fuel (space reactors are typically fast reactors too, so we're talking about something that's almost a bomb there.) An external neutron source does not greatly change the needed enrichment (since any practical subcritical reactor would still need k fairly high, so it is only a bit subcritical.)
      - akiselev 6y ago
        Just read the papers. There are dozens on that archive covering the design, theory, and testing - all of those issues are covered. 20kg is actually a high number optimized for a certain plasma temperature that radiates in UV without losing criticality. All things being equal (enriched uranium hexafluoride), at higher temperatures and pressures the reactor needs far less fuel but it causes too much degradation to the reactor walls to be economical or useful except in cold boots. The terrestrial reactor and the rocket engine versions are different in how they transmit power from the reactor core to do useful work but not radically so - the core irrotational vortex compressing a high temperature plasma in a single crystal beryllium oxide chamber is the same in both designs and has been tested. The difference is in the cooling gas - hydrogen gas seeded with tungsten nanoparticles to absorb the black body radiation of the plasma for the rocket and water going through a steam turbine for terrestrial power generation.
pfdietz 6y ago
It was the unsustainable expense of the Apollo architecture that did that. The decision to cancel was driven by that, not by a "lack of will". It would have made some sense to incrementally improve some parts of that architecture (like the Saturn 1B, for example) rather than going down the Shuttle rabbit hole.
- astroflask 6y ago
  In theory the shuttle promised sustainability. But as the years went by it proved to be more expensive and almost 5x deadlier than the Apollo stack. The shuttle did make sense for some things it was never used (DoD influence there) and it was an incredible piece of technology. It was also the workhorse for a big part of the ISS. But then again, that all happened in LEO, and different things could have been achieved by just iterating over Apollo/Saturn, in LEO and further away.
  - pfdietz 6y ago
    The engineers knew from the beginning that the Shuttle made no sense. The mission numbers used to justify it were always absurd and assumed a flight rate that they knew wasn't going to be achieved.
nickik 6y ago
Had NASA engineers actually build a better design for Space Shuttle, lots of budget would have been available to do more. The Space shuttle could have done much more much better things if it was designed differently.
- pfdietz 6y ago
  And had my father had two X chromosomes, he'd have been my mother. There has to be a reason to entertain contrafactuals; you can't just state them and assume that outcome would have been likely.
  - nickik 6y ago
    The point here being that it was not bureaucracy or the government that trapped NASA in LEO. It was NASA own design process. Blaming everything always on the congress/president is a way for NASA to never take responsibility. All the success gets credit to NASA but failure is always somebody wrong doing.
    - pfdietz 6y ago
      The point I was making was there was no plausible way the shuttle could have been designed so it would have been successful.
      - nickik 6y ago
        Totally disagree. With the same budget a much more successful vehicle could have been built. Simple changes like not going for hydrogen, separating main engines from Shuttle itself, not using hydrogen on the first stage, vertically mounted shuttle and so on.
        pfdietz 6y ago
        No, I don't think so. The underlying problem was the Shuttle was a One Big Bite attempt at developing a very complex technology. That doesn't work. Development of something like that has to be iterative. Shuffling the deck chairs with different propellants wouldn't have made any difference.

akiselev 6y ago

Not only that, but the nuclear rocketry program for Mars was making breakthroughs like the nuclear lightbulb hybrid reactor & closed loop rocket engine [1] - that the public wouldn't see until declassified papers hit JPL's archives in the 2000s. This program was cancelled by Nixon, setting us back at least half a century. [1] https://ntrs.nasa.gov/citations/19730003970 https://ntrs.nasa.gov/citations/19730003970

pfdietz 6y ago
Not really a setback, because there was no place for that technology. Lack of space reactors wasn't and isn't a roadblock. Had that development continued it would have been largely wasted, and the knowledge gained would have decayed away.
- akiselev 6y ago
  It easily functions as a self-breeding terrestrial reactor that reaches criticality with 1/500th to 1/1000th the fuel of existing nuclear reactors (~20kg). The design requires active power that shuts down the reactor on failure, making any accident a complete nonevent. It can even be kickstarted without huge amounts of enriched fuel with the addition of a neutron gun (which they used to test the design without nuclear fuel). The core infrastructure required to support such a reactor are also covered by far less red tape (mostly centrifuges). It would have changed the face of power generation at a critical time for climate change if it was allowed to reach fruition. Instead it was locked away in UTC & NASA archives.
  - pfdietz 6y ago
    The requirements for a space reactor, and for a terrestrial reactor, are radically different. No space reactor will make sense for terrestrial power generation. The temperatures are different, power density is different, safety cases are different. A 20kg reactor likely needs highly enriched fuel (space reactors are typically fast reactors too, so we're talking about something that's almost a bomb there.) An external neutron source does not greatly change the needed enrichment (since any practical subcritical reactor would still need k fairly high, so it is only a bit subcritical.)
    - akiselev 6y ago
      Just read the papers. There are dozens on that archive covering the design, theory, and testing - all of those issues are covered. 20kg is actually a high number optimized for a certain plasma temperature that radiates in UV without losing criticality. All things being equal (enriched uranium hexafluoride), at higher temperatures and pressures the reactor needs far less fuel but it causes too much degradation to the reactor walls to be economical or useful except in cold boots. The terrestrial reactor and the rocket engine versions are different in how they transmit power from the reactor core to do useful work but not radically so - the core irrotational vortex compressing a high temperature plasma in a single crystal beryllium oxide chamber is the same in both designs and has been tested. The difference is in the cooling gas - hydrogen gas seeded with tungsten nanoparticles to absorb the black body radiation of the plasma for the rocket and water going through a steam turbine for terrestrial power generation.

pfdietz 6y ago

It was the unsustainable expense of the Apollo architecture that did that. The decision to cancel was driven by that, not by a "lack of will". It would have made some sense to incrementally improve some parts of that architecture (like the Saturn 1B, for example) rather than going down the Shuttle rabbit hole.

astroflask 6y ago
In theory the shuttle promised sustainability. But as the years went by it proved to be more expensive and almost 5x deadlier than the Apollo stack. The shuttle did make sense for some things it was never used (DoD influence there) and it was an incredible piece of technology. It was also the workhorse for a big part of the ISS. But then again, that all happened in LEO, and different things could have been achieved by just iterating over Apollo/Saturn, in LEO and further away.
- pfdietz 6y ago
  The engineers knew from the beginning that the Shuttle made no sense. The mission numbers used to justify it were always absurd and assumed a flight rate that they knew wasn't going to be achieved.

nickik 6y ago

Had NASA engineers actually build a better design for Space Shuttle, lots of budget would have been available to do more. The Space shuttle could have done much more much better things if it was designed differently.

pfdietz 6y ago
And had my father had two X chromosomes, he'd have been my mother. There has to be a reason to entertain contrafactuals; you can't just state them and assume that outcome would have been likely.
- nickik 6y ago
  The point here being that it was not bureaucracy or the government that trapped NASA in LEO. It was NASA own design process. Blaming everything always on the congress/president is a way for NASA to never take responsibility. All the success gets credit to NASA but failure is always somebody wrong doing.
  - pfdietz 6y ago
    The point I was making was there was no plausible way the shuttle could have been designed so it would have been successful.
    - nickik 6y ago
      Totally disagree. With the same budget a much more successful vehicle could have been built. Simple changes like not going for hydrogen, separating main engines from Shuttle itself, not using hydrogen on the first stage, vertically mounted shuttle and so on.
      - pfdietz 6y ago
        No, I don't think so. The underlying problem was the Shuttle was a One Big Bite attempt at developing a very complex technology. That doesn't work. Development of something like that has to be iterative. Shuffling the deck chairs with different propellants wouldn't have made any difference.