Actually, it sounds like the OP is referring to the Lockheed SSX concept vehicle. I had a picture of this thing on the front of my Linear Controls book. It looks kind of like a rounded frusturm of a four sided pyramid. I can’t find any images on line, but they built a scale model (1:5 or 1:6) of it for testing. It is a single stage to orbit (SSTO) rocket. Pournell was a big advocate of the thing for years, but the Boeing and Orbital Sciences proposals got more actual funding, so it died on the vine (and so did the others, more recently, when the whole concept was given a heave.) Another possibility is the Roton, which always struck me as being a little flukey in concept.
SSTO rockets are good from a standpoint of reusibility–no dealing with discardable stages–but are less efficient due to the amount of dead mass they have to bring all the way to orbit. As a result, the SSTO concepts were all people-transporters, with only a small cargo capacity, not heavy lift vehicles like the Shuttle. There’s a logic to this, in that you can use the SSTO for more frequenty crew rotations or replacement without having to justify the cost of the launch by cramming as many satellites or science missions along with it, but it also means developing a seperate heavy launch capability. Given the problems Boeing has had with the Delta-IV, it’s still a somewhat questionable proposition that we can retire the Shuttle without loss of capability. (One alternative has us using a Shuttle-like frame with SMEs and the SRBs but without crew capability as a heavy launcher, but this never got past proposal stage.)
The concept is technically feasibly from an overall view, but there are detail issues, specifically with the reentry shielding and engine materials, which could make the concept problematic in execution, at least within the budget and timeframe required. Pournell and other advocates tend to gloss over these rather quickly, and no doubt, with sufficient effort and money they could be overcome, but it’s not as if anybody is issuing NASA blank checks these days.
BTW, although the Shuttle is “reusable” that term is best applied to the spaceframe, habitat, and insulating tiles only. The engines require in-depth inspection every flight, and a virtual rebuild every other flight. The Shuttle has turned out to be no less expensive to fly than the Saturn V booster, although in its defense it does have a much greater cargo capacity and greater crew complement.
The most current direction for a manned transport replacement for the Shuttle has us going back to an Apollo-like Crew Exploratory Vehicle or a biconic, which would only be marginally reusable if at all. I don’t know what kind of launch vehicle is intended, but the Russian Energiya booster seems like an ideal candidate, both from a cost and reliabilty standpoint, to use as the basis for the booster stack. This would go back to the expendible launcher, but that may end up being the cheapest way, with available and forseeable technology, to achieve manned orbit.
Another question is just how much longer this whole “Mission to Mars” charade is going to continue. The current Administration is unwilling to fund it to levels actualy required (for NASA) to make significant progress past returning people to orbit and perhaps the the moon, and future budgets and agendas are always in doubt when it comes to space exploration. Meanwhile, JPL is fighting to save valuable unmanned programs from the axe, and Hubble gets tossed in the Pacific. :rolleyes: Film at 11.
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