A 'spaceplane' is a
rocket plane designed to pass the
edge of space. It combines some of the features of an
aircraft and some of a
spacecraft. Typically, it takes the form of a spacecraft equipped with
wings.
Orbital spaceplanes
The ''
orbital'' spaceplanes successfully flown to date, the
United States Space Shuttle and the
Soviet Buran, have used their wings to provide
aerobraking to return from orbit and to provide
lift to allow them to land on a
runway like conventional aircraft. Both these vehicles are still designed to ascend to orbit vertically under
rocket power like conventional
expendable launch vehicles. Each of these vehicles has a much smaller
payload fraction than a ballistic design with the same takeoff weight; this is primarily due to the weight of the wings - around 9-12% of the weight of the atmospheric flight weight of the vehicle. This significantly reduces the payload size, but the reusability is intended to offset this disadvantage.
Suborbital spaceplanes
Other (suborbital) spaceplane designs use the vehicle's wings to provide lift for the ''ascent to'' space as well, in addition to the rocket. As of
June 21,
2004, the only such crafts to reach space have been the
X-15 and
SpaceShipOne. Neither of these craft were capable of entering orbit, and both began independent flight only after being lifted to high altitude by a carrier aircraft.
NASA and
Boeing are currently developing unmanned orbital spaceplane technologies as a low-cost alternative to expendable launch vehicles for
satellite launches (''see
X-34,
X-37,
X-40A'')
Single stage to orbit
Future orbital spaceplanes may take off, ascend, descend, and land like conventional aircraft, providing true
single stage to orbit capability.
Proponents of
scramjet technology often cite such a vehicle as being a possible application of that type of engine, however pure rocket and turbojet designs have also been proposed and may be easier to design and build.
Other designs
Various types of spaceplanes have been suggested since the early twentieth century. Notable early designs include
Friedrich Zander's spaceplane equipped with wings made of combustible alloys that it would burn during its ascent, and
Eugen Sänger's
Silbervogel bomber design. Winged versions of the
V2 rocket were considered during and after
World War II, and when public interest in space exploration was high in the 1950s and 60s, winged rocket designs by
Wernher von Braun and
Willy Ley served to inspire
science fiction artists and filmmakers.
The
USAF invested some effort in a paper-study of a variety of spaceplane projects under their
aerospaceplane efforts of the late 1950s, but later ended these when they decided to use a modified version of Sänger's design. The result
X-20 Dyna-Soar was to have been the first orbital spaceplane, but was cancelled in the early 1960s in lieu of NASA's
Project Gemini and the U.S. Air Force's
Manned Orbiting Laboratory program.
The
Rockwell X-30 National Aero-Space Plane (NASP) was an attempt to build a scramjet vehicle, which failed due to technical issues.
The
Multi-Unit Space Transport And Recovery Device (MUSTARD) was a concept explored by the British Aircraft Corporation (BAC) around 1964-1965 for launching payloads wieghing as much as 5,000 lb. into orbit. It was never constructed.
The
British Government began a project known as
HOTOL whose ultimate goal would have been a spaceplane, but the project was cancelled due to technical and financial issues. The lead engineer from the
HOTOL project has since set up a private company dedicated to creating a similar plane with a different engine, called
Skylon. This vehicle would be capable of a single stage to orbit launch and would be far in advance of anything currently in operation. Whether or not the company will succeed in building such a craft remains to be seen.
In 1994 a design for a single stage to orbit peroxide/kerosene spaceplane called "Black Horse"
[1]. This was notable in that it took off almost empty and underwent mid-
air refuelling before burning for orbit.
The
X-33 was a prototype made as part of an attempt by
NASA to build a
SSTO hydrogen fuelled space plane that failed when the hydrogen tank design proved to be unconstructable in the planned way.
The
Roton was an unusual attempt to build a space plane. Several configurations were evaluated ranging from a helicopter ascent to a pure rocket ascent; all landings were to use a helicopter landing system. It failed due to funding issues.
Unconfirmed reports
The
March 5,
2006 edition of
Aviation Week & Space Technology published a story purporting to be 'outing' a highly classified US military two stage to orbit spaceplane system with the code name
Blackstar,
SR-3/XOV among other nicknames. The alleged system, using an XB-70-like first stage mothership, capable of mach 3, is said to launch a upper stage
wave-rider spaceplane capable of carrying small payloads and crews near or into orbit or on
skip-diving flights, ostensibly for reconnaissance and other missions, achieving surprise that cannot be attained by satellite. There has been considerable controversy over this story and its claims.
The Soviet Union supposedly developed the spaceplane
Uragan in the 1980s. Indended as a follow-on to
Spiral and a smaller sibling to
Buran, the project was cancelled in 1987, a year before the first Buran flight. The project has never been confirmed by Soviet or Russian authorities, however.
See also
★
Reentry
★
Rocket
★
Single stage to orbit
★
Spaceflight
External links
★ http://www.astronautix.com/craft/uraeptor.htm
Encyclopedia Astronautica article on Uragan / Zenit