 carrying two crew and two passengers intended to provide proof-of-concept for the development of the Spacecab/Spacebus spaceplane, and is capable of reaching space (though not orbit). As well as being an entrant for the X-Prize, Ascender is intended to return commercial revenues through its passenger carrying capability.
Spacebus a design for a 2-stage passenger-carrying HTOL by the company Bristol Spaceplanes in Britain. The first stage uses jet engines for take-off, followed by rocket engines to climb to high altitude for separation, after which the upper stage uses rocket engines to reach orbit. This configuration has a number of advantages described at length in papers by David Ashford (including the recent "Space Tourism - How Soon Will it Happen?" and the 1990 book "Your Spaceflight Manual: How you could be a tourist in space within 20 years"). Using existing jet and rocket engines is very attractive in reducing initial development costs. And though new air-breathing rocket engines might be more efficient, they're not needed initially (the first stage just has to be a bit bigger and use a bit more fuel). And going high with the first stage makes separation easy as it's in thin air, so even hypersonic loads are small.
Spacecab is a scaled-down version of Spacebus designed to carry 6 passengers. It's attractive as a first step to HTOL launch services since it uses only existing technology, and could start passenger operations much earlier than a vehicle requiring new engines to be developed.
Michelle, or 'Modular Incremental Compact High Energy Low cost Launch Experiment', is a manned reusable sub-orbital SSTO proposed by TGV Rockets. Its modular structure is designed to allow a variety of payloads such as scientific instrumentation to be substituted.
By aiming at the sub-orbital market first, Michelle aims to bridge the gap to more expensive orbital vehicles by allowing the necessary technology to be developed incrementally.
|ASTRIUM SPACE JET||
EADS Astrium's suborbital HTOL vehicle is a spaceplane designed to carry four passengers 100 km into space, where they will experience three minutes or more of weightlessness during the 90 minute trip.
The Astrium space jet will take off and land conventionally from a standard airport using its jet engines. At about 12 km altitude, a rocket engine takes over to boost the vehicle's altitude to approximately 100 km. After atmospheric re-entry, the jet engines are again restarted for landing.
BSC Spaceship is a VTHL suboribtal space tourism vehicle proposed by the Benson Space Company ( BSC). The design is partly inspired by, and is an amalgam of, a number of NASA and Air Force vehicles including the X-2 and X-15.
The BSC Spaceship is powered by hybrid rocket motors sourced by SpaceDev, and will launch vertically to an minimum altitude of 65 miles. The vehicle is designed to allow for lowered G-forces on re-entry, and features a cabin of large, spread-out windows for improved views of Earth and space.
Armadillo Aerospace is a research and development team headed and funded by computer games entrepreneur John Carmack. The Texas-based team has already developed small manned and unmanned atmospheric test landers powered by hydrogen peroxide rockets. Armadillo Aerospace is now competing for the X-Prize with what it believes to be the simplest possible design.
The rocket, dubbed Black Armadillo, is powered by four hydrogen peroxide engines feeding from a 1000 gallon composite fuel tank. A computer takes attitude measurements from gyroscopes and uses those measurements to throttle the engines 200 times per second, stabilizing the craft. The pilot can also steer the rocket via joystick.
The pilot and two passengers sit with their backs to the nosecone. This unusual position is taken to ensure that the occupants encounter reentry deceleration on their backs as the vehicle reenters the atmosphere nose first. Ascent acceleration is considered by Armadillo Aerospace to be mild enough to permit the unorthodox seating arrangement.
The rocket lifts off vertically, and at burnout coasts up t