For most of the development of the Space Shuttle, until very near the point where the final design was chosen, it was just accepted that the Shuttle would be a two-stage fully reusable vehicle, with the first stage being a manned “Flyback” booster, equipped with wings and jet engines to return it to the launch site for quick and easy refurbishment and re-launch. The Orbiter itself would be equipped with internal propellant tanks, so there’d be no need to drop the External Tanks into the Indian ocean. On the whole, the concept certainly didn’t lack the coolness factor. Here, for example is one of the North American concepts, with two different Orbiters:
What’s not to love? While some of the boosters designs were dishwater-dull, being little more than basic rockets with wings, this NAA concept was an elegant design of blended surfaces.
In the end, of course, NASA went with the SRB’s. The official reason given was that they knew that a flyback booster would be operationally cheaper than the low-efficiency SRBs which needs to be fished out of the ocean and refurbed after each flight, but the SRBs would be cheaper to develop and could fly sooner with a Shuttle with an External Tank. This being the early 1970s, “Cheap Now” won out over “Cheap In The Long Run.”
There was, however, another reason why the flyback boosters were bypassed. They weren’t going to be just expensive to develop… it was becoming apparent that they were going to be NIGHTMARES to develop. They would essentially be subjected to roughly the same speeds and heating rates as the X-15… but would be bigger. The flyback booster is big. Really big. You just won’t believe how vastly, hugely, mindbogglingly big it is. I mean, you may think it’s a long way from nose to tail of a 747, but that’s just peanuts to flyback boosters, look:
The fuselage is several times the size of that of a 747, but the wings are quite small; this is made possible by the fact that the vast bulk of the flyback booster was empty space. Even so, it would have been an enormous vehicle, with a vast surface area.
The Space Shuttle, even after the SRB option was selected, was sold as being a $50 million per flight design, which could be turned around in two weeks by a reasonable number of technicians. And we all know how *that* turned out. I shudder to imagine what maintenance on the flyback booster would have been like.
I have no doubt that a vehicle like this could be designed, built, flown and put into service. I have no doubt that a vehicle like this could be made cost effective and reliable. I have no doubt that had they tried this in the mid-1970’s, it would have either failed, or been a catastrophically expensive hangar queen. That might have spelled the death of manned NASA flights by the mid 1980s… or it might have led to a truly cost effective manned space launch system by the late 1980.s Who knows. As it turned out, the Space Shuttle we actually got was far too expensive to be actually useful, but not so fantastically expensive that the government would easily give it up. Sometimes you need a truly massive financial disaster to cause a complete rethink.
