The US was working on a reusable Gemini. If they had gone the 'Big Gemini' route, you'd have seen a reusable version. Of course, that's just the capsule - but that's all that would have been reusable on Bush's Constellation system. (OK, technically they reuse the SRBs, but the cost is AFAIK just as high as a new build.)
Earlier shuttle?
- Thread starter BlackWave
- Start date
The problem is that the path we took was the optimal in terms of physics and technological progress in other areas.
1) The development of electronics allowed for automated reconnaissance satellites negating the need for a manned presence in that area.
2) ICBMs on ballistic trajectory are superior for delivering nuclear warheads then any space basing. This is due to the dynamics of orbital mechanics. Even something in geosynchronous orbit has issues such as transit times before hitting a target.
IN both programs the development of electronics controlled manned military space program. The Soviet Union actually did launch military missions in two of Salyut stations. But the US effort stalled both because of Apollo sucking the space dollars to it and the fact by the late 60's there was no need for people in space to do what the military wanted.
With that being said there is a couple of ways of this could be gotten around. First is that some even resulted in delaying the miniaturization of US warheads. Key US Physicists dying in the early 50s would do the trick.
The consequence of this would cause the US to develop much heavier rockets sooner. This give the excess payload needed to launch substantial space vehicles in the early 60s. This is what happened to the Soviet program, the large rockets needed to launch their warhead gave them an early advantage in getting into space.
With the early availability of high payload rockets, the US could have match the Soviet Union triumphs thus forestalling urgency that led to the moon race. This would have given them means of actually launchig something like the Gemini-MOL in the late 60s (instead of being in development) along with Dyna-Soar. Although by the 70s it would have all been shut down anyway as both small nuclear warheads and electronics would have caused the various space programs to turn to unmanned satellites.
Likely afterwards there would have been a manned space program with the same level of funding and prestige as the various Antarctica programs. Possibly a moon race could have ignited in the 70s as a last gasp use of the infrastructure laid down in the 60s.
A few thoughts...
robertsconley makes some interesting points, but he treates them as deterministic, rather than as outgrowths of existing political decisions. The emphasis on unmanned satellites was a direct result of Eisenhower's decision to emphasize the Corona project, in large part due to his deep distrust of the CIA and the U-2 program. Corona mandated (as robert correctly points out) the development of advanced unmanned technologies, but there was no particular reason that this was the only path forward. The Army certainly favored a manned recon approach, and the Navy (though it remained largely neutral) did quite a bit of research in this area as well.
Regarding ICBMs, robert is partially correct, but once again, treats it as a technical certainty, rather than an outgrowth of choice. The original nuclear weapons were multiton, but their size declined quickly. Thermonuclear wearheads were originally huge (MIKE was the size of a small house), but by the mid/late 1950s these were a fraction of their previous size. Ironically, the Soviets (who were far, far behind in the race to miniaturize warheads) ended up with ICBMs far bigger than those developed by the US, and thus were better placed to launch their early (very heavy) spacecraft. The point here is that by the mid/late 50s, there was no particular mandate for larger boosters inherent in the ICBM program (the Titans and Atlases were able to handle these jobs quite nicely), and these boosters would also support a robust manned program.
The real problem was (again) political. Eisenhower made it clear that the civilian agency would hold the only ticket into space, and thus curtailed (or outright cancelled) any alternative approaches. NASA, while it had some wonderful people working for it, was primarily a group of tinkerers with very little project management experience, and even less support from the aerospace community that had real background in building working aircraft. This is not to suggest that NASA was utterly incompetent, but there is very little doubt (for instance) that their management of the Mercury program was deeply flawed, and that their engineering follow-ups (most notably Apollo) were less efficient than they might have been.
A useful POD then might have been Eisenhower having a change of heart (or a more serious heart attack) in 1955 or so, altering his opposition to a more 'competitive' manned space program. With the various military branches competing (as well as a possible NASA) there is very little doubt that we would have seen successful launches ahead of the Russians in terms of both satellites and manned space. Note that Von Braun's people were quite ready to launch Explorer ahead of the Russian Sputnik, but were delayed by the White House, as the decision had been made to launch Vanguard first. The story of the Mercury program is murkier, but no less depressing. My point here (and yes, there IS a point here....) is that the military (and the various aerospace contractors) all had well-developed plans that could have been pursued, but the emphasis on a single road to space killed them far more effectively than any technological or physical limitations.
As for what would happen as a result of the POD long-term, there would likely have been a cluster of different space systems early on (including things like DynaSoar), probably with a much greater emphasis on large launch rates with smaller boosters (cheaper to develop and deploy) than low launch rates with larger boosters (much more complex technologically) leading to a greater degree of expertise with in-orbit assembly, refueling, etc. This would have led us to a sustainable infrastructure even as technology advanced, improving the quality of what was being launched.
robertsconley makes some interesting points, but he treates them as deterministic, rather than as outgrowths of existing political decisions. The emphasis on unmanned satellites was a direct result of Eisenhower's decision to emphasize the Corona project, in large part due to his deep distrust of the CIA and the U-2 program. Corona mandated (as robert correctly points out) the development of advanced unmanned technologies, but there was no particular reason that this was the only path forward. The Army certainly favored a manned recon approach, and the Navy (though it remained largely neutral) did quite a bit of research in this area as well.
Regarding ICBMs, robert is partially correct, but once again, treats it as a technical certainty, rather than an outgrowth of choice. The original nuclear weapons were multiton, but their size declined quickly. Thermonuclear wearheads were originally huge (MIKE was the size of a small house), but by the mid/late 1950s these were a fraction of their previous size. Ironically, the Soviets (who were far, far behind in the race to miniaturize warheads) ended up with ICBMs far bigger than those developed by the US, and thus were better placed to launch their early (very heavy) spacecraft. The point here is that by the mid/late 50s, there was no particular mandate for larger boosters inherent in the ICBM program (the Titans and Atlases were able to handle these jobs quite nicely), and these boosters would also support a robust manned program.
The real problem was (again) political. Eisenhower made it clear that the civilian agency would hold the only ticket into space, and thus curtailed (or outright cancelled) any alternative approaches. NASA, while it had some wonderful people working for it, was primarily a group of tinkerers with very little project management experience, and even less support from the aerospace community that had real background in building working aircraft. This is not to suggest that NASA was utterly incompetent, but there is very little doubt (for instance) that their management of the Mercury program was deeply flawed, and that their engineering follow-ups (most notably Apollo) were less efficient than they might have been.
A useful POD then might have been Eisenhower having a change of heart (or a more serious heart attack) in 1955 or so, altering his opposition to a more 'competitive' manned space program. With the various military branches competing (as well as a possible NASA) there is very little doubt that we would have seen successful launches ahead of the Russians in terms of both satellites and manned space. Note that Von Braun's people were quite ready to launch Explorer ahead of the Russian Sputnik, but were delayed by the White House, as the decision had been made to launch Vanguard first. The story of the Mercury program is murkier, but no less depressing. My point here (and yes, there IS a point here....) is that the military (and the various aerospace contractors) all had well-developed plans that could have been pursued, but the emphasis on a single road to space killed them far more effectively than any technological or physical limitations.
As for what would happen as a result of the POD long-term, there would likely have been a cluster of different space systems early on (including things like DynaSoar), probably with a much greater emphasis on large launch rates with smaller boosters (cheaper to develop and deploy) than low launch rates with larger boosters (much more complex technologically) leading to a greater degree of expertise with in-orbit assembly, refueling, etc. This would have led us to a sustainable infrastructure even as technology advanced, improving the quality of what was being launched.
Would such a program have led to more accidents? And what would the results of those accidents be?
There was a discussion in a similiar vein to this one in the "What if Pedro Paule Went Public" thread. Basically, in 1896 there was an Argentinian inventor that created the world's first rocket, albiet strapped to a table. If he had flown it in the air before a large press gathering in 1896, the history of rocketry could have been significantly accelorated. If you could use it to butterfly away the Versaille Treaty ending to WWI, thus preventing the Great Depression, then you have two decades of invention and advancement. You could even have someone build something similiar to a V-1 program in WWI, further accelerating the process.
Cook
Banned
It’s not going to spring fully grown out of his forehead; it’s the concept of reusable space planes having priority over single shot missiles that is required. It’ is like Von Braun’s early ideas and the Saturn V, there is a vague resemblance only.
But everyone in the early days of rocketry knew that reusable spacecraft would be better--von Braun had his shuttle, too, you know. It's just that the materials science to make such things practical wasn't there, was barely there in the '70s, and may or may not be all the way there today (we haven't tried lately because of how spectacularly the last go DIDN'T work).
Reusable vs Spaceplanes
Spaceplanes are not by definition reusable (though it is easier to do so), and reusable spacecraft don't have to be spaceplanes. Truth is Life is right that the materials science for fully reusable spacecraft wasn't there in the early days (may not be there now, but that is a different issue), but clearly it was possible to build spaceplanes (my favorite hobbyhorse, the Dynasoar, is a good example) with comparatively primitive (by today's standards) materials. Perhaps the boosters couldn't be reused, but the spaceplane itself (the really expensive part) could be, and that was what really mattered.
Actually, what really mattered was getting something that could be launched often, which would then allow the development costs to be spread over a large number of launches. This would also allow more flexibility in terms of payloads, so if one mission aborted (or was destroyed), nothing essential would be lost. Right now if a shuttle flight (or even a Progress launch) is disrupted for some reason, there is a huge amount of work (some of it vital) tied to the cargo on that launch. If you are launching 1/week (an admittedly very aggressive schedule), you can spread your cargos over a significant number of carrier vehicles, while if you launch 1/10 weeks, you are pretty much stuck with a 'big bang' approach.
A high launch rate also lets you move towards in-space assembly, which while extremely difficult to master, is the only way to scale up to large, complex spacecraft/satellites/space stations in the long run. There is a limit to what can be crammed into even the biggest booster (and as a side note, heavy lift vehicles are extremely difficult - and expensive - to engineer), and the sheer cost of these vehicles leads back to low launch rates, low flexibility, etc. With in-orbit assembly, you can develop fuel depots (note that fuel, oxygen, and water are the biggest items carried into orbit by weight) which can be filled up with lots of cheap unmanned launches, while the much smaller, more expensive components can be sent up with smaller boosters and assembled on-site.
Note that the word 'reusable' hasn't cropped up here, nor has 'spaceplane'. Yes, spaceplanes offer more cross-range capabilities (i.e. you have more places you can land and you can do so over a broader area), but there is nothing magical that makes them vital for useful space access. In the same sense, reusable (or at least partially reusable) spacecraft would be a big advantage (particularly the non-booster components), but high launch rates probably matter more, depending upon how much it costs to make a system reusable.
Spaceplanes are not by definition reusable (though it is easier to do so), and reusable spacecraft don't have to be spaceplanes. Truth is Life is right that the materials science for fully reusable spacecraft wasn't there in the early days (may not be there now, but that is a different issue), but clearly it was possible to build spaceplanes (my favorite hobbyhorse, the Dynasoar, is a good example) with comparatively primitive (by today's standards) materials. Perhaps the boosters couldn't be reused, but the spaceplane itself (the really expensive part) could be, and that was what really mattered.
Actually, what really mattered was getting something that could be launched often, which would then allow the development costs to be spread over a large number of launches. This would also allow more flexibility in terms of payloads, so if one mission aborted (or was destroyed), nothing essential would be lost. Right now if a shuttle flight (or even a Progress launch) is disrupted for some reason, there is a huge amount of work (some of it vital) tied to the cargo on that launch. If you are launching 1/week (an admittedly very aggressive schedule), you can spread your cargos over a significant number of carrier vehicles, while if you launch 1/10 weeks, you are pretty much stuck with a 'big bang' approach.
A high launch rate also lets you move towards in-space assembly, which while extremely difficult to master, is the only way to scale up to large, complex spacecraft/satellites/space stations in the long run. There is a limit to what can be crammed into even the biggest booster (and as a side note, heavy lift vehicles are extremely difficult - and expensive - to engineer), and the sheer cost of these vehicles leads back to low launch rates, low flexibility, etc. With in-orbit assembly, you can develop fuel depots (note that fuel, oxygen, and water are the biggest items carried into orbit by weight) which can be filled up with lots of cheap unmanned launches, while the much smaller, more expensive components can be sent up with smaller boosters and assembled on-site.
Note that the word 'reusable' hasn't cropped up here, nor has 'spaceplane'. Yes, spaceplanes offer more cross-range capabilities (i.e. you have more places you can land and you can do so over a broader area), but there is nothing magical that makes them vital for useful space access. In the same sense, reusable (or at least partially reusable) spacecraft would be a big advantage (particularly the non-booster components), but high launch rates probably matter more, depending upon how much it costs to make a system reusable.
Archibald
Banned
Spaceplane galore ! I toyed with the idea today.
Left to right (from above) are some pre-shuttle Reusable Launch Vehicles of the 60's.
North American fully reusable shuttle (1971)
Martin Marietta Astrorocket (1965)
Mc Donnell Douglas Pegasus - a Philip Bono design of 1965
Lockheed's Starclipper (1968)
General Dynamics Triamese (1968)
And, lastly, Boeing DynaSoar (1962)
Left to right (from above) are some pre-shuttle Reusable Launch Vehicles of the 60's.
North American fully reusable shuttle (1971)
Martin Marietta Astrorocket (1965)
Mc Donnell Douglas Pegasus - a Philip Bono design of 1965
Lockheed's Starclipper (1968)
General Dynamics Triamese (1968)
And, lastly, Boeing DynaSoar (1962)
What, no love for Grumman?
Early 1970s proposal from Grumman. Their H33 Orbiter, above the large manned booster stage, had two LH2 drop tanks. Eventually, Grumman and Boeing modified the idea so that H33 would be developed first and launched on S-IC stages. Obviously, it was never developed even to that point. http://www.astronautix.com/lvs/shuleh33.htm
Early 1970s proposal from Grumman. Their H33 Orbiter, above the large manned booster stage, had two LH2 drop tanks. Eventually, Grumman and Boeing modified the idea so that H33 would be developed first and launched on S-IC stages. Obviously, it was never developed even to that point. http://www.astronautix.com/lvs/shuleh33.htm
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Might it not cripple the space race as the space shuttle did?
It sticks people to this one single launch platform, they're not going to go off and try different designs if they've got this one. Then there's that it isn't entirely reusable, it still costs something like half a billion a launch- expensive fuel, it wastes its boosters and fuel tanks.
It sticks people to this one single launch platform, they're not going to go off and try different designs if they've got this one. Then there's that it isn't entirely reusable, it still costs something like half a billion a launch- expensive fuel, it wastes its boosters and fuel tanks.
Archibald
Banned
Ah, yes, the Grumman concept ! Excellent, one more aerospace giant with yet another diffrent design !
And of course Chrysler (yes, even car makers tried their hands at shuttle !) had the SERV, a very detailed SSTO study...
http://www.pmview.com/spaceodysseytwo/spacelvs/sld034.htm
Archibald
Banned
To make this bunch of spaceplanes "real" I imagined a radical departure from Apollo.
Two majors PoDs happens in 1961 and 1962.
Late July 1961 John Houbolt (Lunar orbit rendezvous) die when its plane catch fire.
Then, a year later, the F-1 problems (it exploded because of combustion instability) can't be solved.
Thus NASA most powerful rocket is Saturn C-2 with 50 000 pounds to LEO.
http://en.wikipedia.org/wiki/Saturn_C-2
And then NASA needs 7 to 15 launches for any lunar landing ! Bad on the short term - it complicates the mission - good over the long term.
Indeed those 50 000 pounds are typical spaceplane payload. Over the long term NASA replaces the bunch of Saturn C-2 by a noria of spaceplanes...
Two majors PoDs happens in 1961 and 1962.
Late July 1961 John Houbolt (Lunar orbit rendezvous) die when its plane catch fire.
Then, a year later, the F-1 problems (it exploded because of combustion instability) can't be solved.
Thus NASA most powerful rocket is Saturn C-2 with 50 000 pounds to LEO.
http://en.wikipedia.org/wiki/Saturn_C-2
And then NASA needs 7 to 15 launches for any lunar landing ! Bad on the short term - it complicates the mission - good over the long term.
Indeed those 50 000 pounds are typical spaceplane payload. Over the long term NASA replaces the bunch of Saturn C-2 by a noria of spaceplanes...
Diversity
Spaceplanes are primarily useful for personnel transport, but (as you correctly point out) thermal considerations make them ill-suited for cargo. A big, dumb booster (or a lot of little, dumb boosters) are fine for cargo (perhaps for personnel transport as well), though the inherent flexibility (reusability is entirely secondary) of a spaceplane might be best there.
This is my whole point about large launch rates and small launchers. Small launchers lend themselves to diversity, and hence to a variety of different approaches (and specialized systems) at a lower cost.
Spaceplanes are primarily useful for personnel transport, but (as you correctly point out) thermal considerations make them ill-suited for cargo. A big, dumb booster (or a lot of little, dumb boosters) are fine for cargo (perhaps for personnel transport as well), though the inherent flexibility (reusability is entirely secondary) of a spaceplane might be best there.
This is my whole point about large launch rates and small launchers. Small launchers lend themselves to diversity, and hence to a variety of different approaches (and specialized systems) at a lower cost.
The disparity in cost between manned and unmanned in OTL is what set the technology path we went on. While the distrust did exist, something like Corona would have happened because it was a great advantage over U-2 overflights. And considerably cheaper than trying to get people up there. Perhaps it would been delayed a few years but the consequence would have been no space reconnaissance not a shift into manned military flight.
If you read Dark Sun and other books on the design of nuclear warhead the miniaturization was develop from a breakthrough by Stanislaw Ulam. They would have figured it out someday but Ulam figured out it early enough that effected the design of the first generation of ICBMs. In short it was a bit of a relief as the payload could be made a lot smaller than the original estimates.
If Ulam had died in a car accident or something similar then the miniaturization technology would not have been developed as soon which would have meant that the early ICBM would be designed to launch a much bigger payload. Which would meant that the US could have match Soviet stunts much sooner and launched ambitious projects in the early sixties instead of having to wait until the mid 60s to launch large payloads.
You mentioned that Eisenhower distrusted the CIA. Eisenhower was also budget conscious and only support project to extent to what he felt was to be a national goal. So he would not have supported the development of large payload ICBM (which you need for spaceplanes) unless there was reason to do so. Heavyweight Nuclear Warheads would have provided such a reason. In addition with the reconnaissance that was being done from all sources. A true picture of Soviet nuclear capability emerged Esinhower realized that the US was far far ahead. Thus lessening the need for expensive measures.
The Altas were marginal in their ability to launch manned spacecraft. A consequence of the early successful miniaturization of spacecraft. The US could not match Soviet space efforts until the mid 60s when the Titans came available. Earlier Titans did not have payload need to do anything consequential for manned space. Dynasoar was paced by the need to fit it on the available boosters. With larger payload rockets more could have done sooner and hopefully before McNamara got his finger in and kill Dynasoar.
I suspect that we agree more than we disagree...
Corona was absolutely going to happen anyway, but without Eisenhower's almost pathological (and somewhat justified) distrust of the CIA, it likely would have ended up as a 'nice to have' rather than a central focus that tended to draw everything else in. By 1957/58, virtually everything being done in booster development was being done with Corona in mind, with disastrous results for almost everything OTHER than Corona. If we assume that Corona was just one priority among many, it isn't too hard to imagine several different approaches to the problem (different sized boosters, different technical approaches to manned space, automation, etc.) being approached. Just as JFK's Apollo focus left every other method of getting into space subordinated to Apollo (thus killing numerous programs with great promise), Corona did the same thing in the 1950s.
While there is no question that Corona was cheaper than manned space, it was also FAR more expensive than U-2s, and far less capable in many ways. Corona couldn't provide time sensitive intelligence, was very limited in terms of SIGINT and dust collection - essential for nuclear testing monitoring - and was also (largely as a result of the state of launcher technology) far less reliable in general. There is a reason that the U-2 survived (and in the guise of the TR-1 and follow-ons, still survives) for such a long time. It can be argued (and was argued) that a manned space/U-2 mix would give better strategic intelligence than would Corona, but it ran into the Eisenhower distrust of the CIA every time.
I have indeed read Dark Sun (the last book in the series is due out shortly, as I understand it), and found the discussion of Ulam interesting. My father knew Ulam reasonably well, and loved to tell stories about his propensity for practical jokes, but that is another story... To return to your point, however, Ulam's breakthrough was essential, but the lack of it might have simply meant that the US pursued manned bombers for longer than in our time line. Big boosters were a very serious problem for the US early on, largely because of issues with fueling. It doesn't strike me as especially likely that this was going to be sped up a great deal (the empahsis on ICBM development in OTL was already pretty much maxing out the technical talent available), and bombers were (comparatively) cheaper and easier to build at the time. I am not suggesting that your scenario is possible, only that it is somewhat less likely than that of simply pursuing manned aircraft (B-70, anyone?) for a bit longer while ICBMs caught up.
I am not entirely sure that I share your assessment that a big booster is necessary for a spaceplane. For a DynaSoar, you absolutely need a fairly capable vehicle, but an early model spaceplane (fewer passengers, etc.) is far less demanding. More to the point, however, smaller boosters could easily handle capsules (the Atlas had a significant payload margin for the Mercury, for instance, and could have handled any one of the various MISS designs that were circulating in the mid to late 1950s), and something the size of a DynaSoar wouldn't be ready before the bigger boosters were online in any case. As a side point, I believe that spaceplanes would have eventually ended up as a solution for personnel transport (though not for cargo, this is the biggest design flaw in the shuttle), but there are plenty of excellent capsule-centric approaches as well. The Gemini spacecraft was far superior to the Apollo, for instance, and Big Gemini would have been better still. The advantage of smaller boosters in this sense is that payloads would have been broken up, and we might have ended up with cargo rockets (much simpler and easier...and cheaper...to build) for bulk payloads with spaceplanes, capsules, and other low margin vehicles for people. As my liberal friends like to say...DIVERSITY!
Dynasoar was an outgrowth of the X-15 program I don't see the CIA being involved thus not much of a factor. I do however see the knowledge that the US vastly out matched the soviets in quantity of nuclear weapons being a big factor in Eisenhower giving the green light to an ambitious manned space program.
The bomber vs ICBM controversy was only a problem just after World War II and Vannevar Bush was largely responsible for that. That could be another PoD about the development of large rockets. But even if the PoD negated the Bush led opposition that still wouldn't get the OP's desire for spaceplane. The best opportunity was when Dynasoar was being developed out of the X-15 program. See Milton O Thompson, At the Edge of Space for a view of the early Dynasoar program.
The divergence that I elude about Nuclear Warhead is about development of the Atlas rocket in the early 50s. When Eisenhower was inaugurated he instituted his "New Look" for america's strategic defense which relied on nuclear weapons.
The big problem was guidance of rockets which was crappy. But with the Hydrogen bomb it wasn't a factor. A miss of several miles meant the target was wiped out. So the question was how much rocket will they need to lift the warhead? And because of Ulam's breakthrough it turned out to be a lot lighter than anybody figured.
By the early 50's the rocket was going to get built. That wasn't the question. Rather how big of a rocket needed was. One of the better accounts of the process can be found in Countdown by Heppenheimer roughly pages 64 to 85. The Atlas big competitor was the Navaho Cruise Missile. But the Navaho has severe technical problems and likely would have never flown.
A Dynasoar was small for a spaceplane only one man to pilot it. Not much room to make it smaller. The program would have been similar to the X-15, run as a series of test flight to gather data. And the big issue of the early Dynasoar program was the booster. With larger ICBM earlier in the inventory one of Dynasoar's problems would have been easily overcome.
As they say in the space program, weight is everything. The Atlas-D did not have much margin. In fact the base Atlas-D could only loft 3,000 lbs to oribt. They had to make a special version for Mercury that could lift 6,720 lbs into orbit. Given the history of weight growth in all the manned program I can't see any of the winged MISS designs being used on the booster of the early 60s.
The Titan 1 developed along the Atlas as a backup only could loft 1,800 lb.
All of these rockets were sized according to the size of the warhead they needed to deliever. Up the size of the warhead a bigger rocket would have been designed. It what happened to the Soviets in the same circumstances.
Note Mercury weighed 4,200 lbs compared to Dynasoar's 11,000 lbs. I studied this quite a bit in creating a switch accurate simulator of the Mercury Space Capsule. (http://www.ibiblio.org/mscorbit).
Well, the smallest POD I can think of would be to have Robert A. Lovett accept Kennedy's invitation to be brought into the Cabinet as Secretary of State. From there the X-20 Program "may" survive. Lovett would certainly not be as opposed to it as McNamara, but then again you have two separate space programs running, and in ways competing against one another.
So let us say Lovett allows for the military space program to continue, and even manages to get its budget increased. The X-20 launches as it was intended in July of 1966, and later becomes the main vehicle for the MOL Program. Of course, the Big Gemini could still be developed, and may be required given that the X-20 is not built well as an effective cargo ferry.
Anyway, having Robert Lovett is the simplest scenario I can think of that allows for early development of some sort of Space Shuttle.
So let us say Lovett allows for the military space program to continue, and even manages to get its budget increased. The X-20 launches as it was intended in July of 1966, and later becomes the main vehicle for the MOL Program. Of course, the Big Gemini could still be developed, and may be required given that the X-20 is not built well as an effective cargo ferry.
Anyway, having Robert Lovett is the simplest scenario I can think of that allows for early development of some sort of Space Shuttle.