Editing SpaceShipOne (section)

===Vehicle description===
The fuselage is cigar-shaped, with an overall diameter of about {{convert|1.52|m|abbr=on}}. The main structure is of a [[graphite]]/[[epoxy]] [[composite material]]. From front to back, it contains the crew cabin, oxidizer tank, fuel casing, and rocket nozzle. The craft has short, wide wings, with a span of {{convert|5|m|abbr=on}} and a [[Chord (aircraft)|chord]] of {{convert|3|m|abbr=on}}. Large vertical tailbooms are mounted on the end of each wing, with horizontal stabilizers protruding from the tailbooms. It has gear for horizontal landings.

The overall mass of the fully fueled craft is {{convert|3600|kg|abbr=on|lk=in}}, of which {{convert|2700|kg|abbr=on}} is taken by the fully loaded rocket motor. Empty mass of the spacecraft is {{convert|1200|kg|abbr=on}}, including the {{convert|300|kg|abbr=on|adj=on}} empty motor casing.<ref name="ssone">{{cite web|url=http://www.astronautix.com/s/spaceshipone.html|archive-url=https://web.archive.org/web/20161228034631/http://astronautix.com/s/spaceshipone.html|url-status=dead|archive-date=December 28, 2016|title=SpaceShip One|website=www.astronautix.com}}</ref><ref name="sdhyb">{{cite web|url=http://www.astronautix.com/s/spacedevhybrid.html|archive-url=https://web.archive.org/web/20161228044350/http://astronautix.com/s/spacedevhybrid.html|url-status=dead|archive-date=December 28, 2016|title=SpaceDev Hybrid|website=www.astronautix.com}}</ref>

Originally the nozzle protruded from the back, but this turned out to be aerodynamically disadvantageous. In June 2004, between flights [[SpaceShipOne flight 14P|14P]] and [[SpaceShipOne flight 15P|15P]], a fairing was added, smoothly extending the fuselage shape to meet the flared end of the nozzle. On flight 15P the new fairing overheated, due to being black on the inside and facing a hot, black nozzle. The fairing softened, and the lower part crumpled inwards during boost. Following that flight the interior of the fairing was painted white, and some small stiffening ribs were added.

The craft has a single unsteerable and unthrottleable [[hybrid rocket]] motor, a cold gas [[reaction control system]], and aerodynamic [[Flight control surfaces|control surface]]s. All can be controlled manually. See the separate section below concerning the rocket engine.

The reaction control system is the only way to control spacecraft attitude outside the atmosphere. It consists of three sets of thrusters: thrusters at each wingtip control roll, at the top and bottom of the nose control pitch, and at the sides of the fuselage control yaw. All thrusters have redundant backups, so comprising twelve thrusters in all.

The aerodynamic control surfaces of SpaceShipOne are designed to operate in two distinct flight regimes, subsonic and supersonic. The supersonic flight regime is of primary interest during the boost phase of a flight, and the subsonic mode when gliding. The craft has separate upper and lower rudders, and [[elevon]]s. These are controlled using [[aviation]]-style stick and pedals. In supersonic mode the trim tabs are controlled electrically, whereas the subsonic mode uses mechanical cable-and-rod linkage.

The wings of SpaceShipOne can be pneumatically tilted forwards into an aerodynamically stable high-[[drag (physics)|drag]] "feathered" shape. This removes most of the need to control attitude actively during the early part of reentry: Scaled Composites refer to this as "care-free reentry". One of the early test flights actually performed re-entry inverted, demonstrating the flexibility and inherent stability of [[Burt Rutan]]'s "[[shuttlecock]]" design. This feathered reentry mode is claimed to be inherently safer than the behavior at similar speeds of the [[Space Shuttle]]. The Shuttle undergoes enormous aerodynamic stresses and must be precisely steered in order to remain in a stable glide. (Although this is an interesting comparison of behavior, it is not an entirely fair comparison of design concepts: the Shuttle starts reentry at much higher speed than SpaceShipOne, and so has some very different requirements. SpaceShipOne is more similar to the X-15 vehicle.)

An early design called for a permanently shuttlecock-like shape, with a ring of [[feather]]-like stabilising fins. This would have made the spacecraft incapable of landing independently, requiring [[mid-air retrieval]]. This was deemed too risky, and the hybrid final design manages to incorporate the feathering capability into a craft that can land in a conventional manner. The tiltable rear sections of the wings and the tailbooms are collectively referred to as "the feather".

The landing gear consists of two widely separated main wheels and a nose skid. These are deployed using springs, assisted by gravity. Once deployed, they cannot be retracted inflight.

The spacecraft is incapable of independent takeoff from the ground. It requires a launch aircraft to carry it to launch altitude for an [[air launch]].

The parts of the craft that experience the greatest heating, such as the leading edges of the wings, have about {{convert|6.5|kg|abbr=on}} of ablative thermal protection material applied. The main ingredient of this material was accidentally leaked to ''Air and Space''{{Clarify|date=February 2010}}. If it flew with no thermal protection, the spacecraft would survive reentry but would be damaged.

The spacecraft's aerodynamic design has an acknowledged "known deficiency" that makes it susceptible to [[flight dynamics|roll]] excursions. This has been seen on [[SpaceShipOne flight 15P]] where wind shear caused a large roll immediately after ignition, and [[SpaceShipOne flight 16P]] where circumstances not yet fully understood caused multiple rapid rolls. This flaw is not considered dangerous, but in both of these flights led to the achievement of a much lower altitude than expected. The details of the flaw are not public.