stage accelerates the orbiter to around mach 3 at 30km altitude; the relatively low velocity compared to other booster designs allows a simpler and less complex design. Proposed by Space Tour, an unmanned cargo carrying variant is also on the drawing board.
|DELTA CLIPPER (DC-X,
DC-XA, CLIPPER GRAHAM)
The Delta Clipper was a proposed VTOL orbital vehicle. The DC-X and later DC-XA (derived from the DC-X) were low-speed, reusable test-vehicles built by McDonnell Douglas which flew 12 times between 1993-96, until suffering major fire damage after falling over when a leg failed to deploy on landing. On a total budget of about $100 million provided mainly by the US Department of Defense (DoD) and McDonnell Douglas Aerospace, they demonstrated that reusable rocket vehicles can be flown repeatedly and routinely by a small team - essentially like an aircraft.
Having inherited the project from the DoD, NASA cancelled it after spending some $40 million. Instead, NASA spent $1,300 million over 5 years on the X-33 and X-34, neither of which ever flew before being cancelled. Go figure!
It's notable that, apart from its computers, the DC-X could have been built 30 years earlier - and indeed a proposal for such a vehicle was made at that time by the Douglas company, a fore-runner of McDonnell-Douglas. Why it wasn't built, and why NASA cancelled the the DC-XA, are key to the stagnation in the space industry.
A sea-launched sub-orbital VTOHL rocket using LNG/ LOX engines, the CAC-1 was intended to carry six passengers from port city to port city as a rapid transit service, a transatlantic flight taking about 12 minutes. Designed and promoted by Advent Launch Services, the project was eventually scrapped after the company failed to raise sufficient financing through a deposit scheme. The original start of commercial service was to be July 4 1999. A former X-Prize contender.
A piloted, reusable SSTO VTOL rocket designed in the 1960s by Philip Bono of the (then) Douglas Aircraft company - the source of much SSTO VTOVL thinking. Based on the 3rd stage of the Saturn rocket, this would have been a great way to exploit some of the systems developed for the Apollo project. For political reasons SASSTO was not developed; the Saturn rocket was thrown away; and we had to wait until 1993 for the (much less capable) DC-X to demonstrate the first steps of the VTOVL approach.
SASSTO was one of the earliest SSTO concepts to be proposed. It is the ancestor of Beta and Phoenix, which was in turn the inspiration for Roton, Kankoh-Maru and New Shepard. For more on SASSTO and some of the other vehicle designs in the same family, see "History of the Phoenix VTOL SSTO and Recent Developments in Single-Stage Launch Systems".
A technologically advanced 4 passenger SSTO spaceplane design from the company Lonestar Space Access (formerly Dynamica Research), Cosmos Mariner uses conventional jet engines for take-off and landing, thus allowing it to use the existing FAA air traffic control system and make use of existing airport infrastructure, an issue which VTOL rockets have yet to address. The rocket engines are also planned to use jet fuel which is considerably less volatile than liquid hydrogen. Cosmos Mariner requires advanced and as yet undeveloped technologies though not all of them were needed for its X-Prize bid.
A design for a reusable SSTO VTOL by Dietrich Koelle at MBB in the early 1970s (see "Beta, A Single Stage Reusable Ballistic Space Shuttle Concept"). A key study keeping the VTOL lineage alive! BETA 2 was a later version.
One of the key vehicle designs in the lineage of VTOL rockets. Designed primarily by Gary Hudson and produced during the 1980s by Pacific American Launch Systems in a number of versions, including the "E" (excursion) version to carry passengers for the " Project Space Voyage" with the travel company Society Expeditions in 1985. Many of the same team went on to work on ROTON.
Planned by Rotary Rocket Inc, the Roton was to use a centrifugally-pumped rocket motor for launch, and a helicopter rotor for descent. By their own estimate Ro