Spaceplane
A spaceplane is a hybrid of a plane and a rocket capable of atmospheric flight with wings and spaceflight with reaction engines. Most spaceplanes are single-stage-to-orbit capable or have only some minor parts which aren't reusable. Because there is no disadvantage currently with not reusing parts, the biggest advantage of spaceplanes in comparison to rockets is not present currently.[outdated]
Contents
Construction
Spaceplanes are usually built in the Space Plane Hangar and launched from the runway, and some are launched from the launchpad — often with a rocket reaching space.
Various pre-built stock planes are available, but only the Aeris 4A has the means to reach space and would qualify as a space plane.
Propulsion
Jet engines can efficiently propel craft in Kerbin and Laythe's atmospheres. In space or oxygen-free atmospheres, less efficient reaction engines must be used. Reaction engines sometimes replace jet engines to simplify construction without restricting the craft to oxygenated atmosphere, but reducing the efficiency even more. A plane with only jet engines cannot reach a stable orbit because its engines will shutdown before leaving the atmosphere. Although atmospheric acceleration can achieve a high apoapsis, the periapsis stays within the atmosphere. Raising the periapsis out of the atmosphere requires non-airbreathing engines.
Maneuvering
Winglets, control surfaces, or reaction wheels enable atmospheric maneuvering, with RCS sometimes used in extreme situations. Winglets are useless in space. SAS is commonly maintains attitude while in atmosphere lest the spaceplane tilt if its center of mass is not at its center of lift.
Landing
Landing is most often done with only landing gear, which was also used during takeoff. Parachutes, rocket engines, and the gear's built-in brakes can slow the craft. During emergencies or beyond good landing spots, separating the command module and landing it with parachutes can save the crew in dense atmospheres.
Runway
Kerbin has two runways whereupon spaceplanes can land. The first is at KSC, where most spaceplanes are also launched. It is long and wide. If an approach fails, landing is still possible on the flat surrounding area. The second runway, at the Insular Airfield, is a grass landing strip, much shorter and narrower than the KSC runway, impeding landing.
Elsewhere
Any sufficiently flat terrain can be landed on. Most celestial bodies have among occasional mountain ranges, cliffs, or craters some flats. Smaller bodies' terrain, especially Mun's, is usually rougher than larger ones', there impeding landing.
Without an atmosphere
Landing a spaceplane without an atmosphere is more difficult than landing within one. The plane's wings' mass increase inertia and can break. Normal landing gears cannot be vertically landed on because they face 90 degrees off retrograde. Landing difficulty increases with gravity, usually requiring small vertical rockets or tail-mounted landing legs. A plane's cockpit can be a lander that returns to orbit and docks with its ship's winged part.
Purposes
- Refueling space stations in orbit around Kerbin
- Landing on Kerbin with the possibility of reuse
- Landing on and ascending from such atmospheric bodies as Laythe, Duna or Eve
See also
- Spaceplane on Wikipedia
