Reusable launch system

Vehicles that land horizontally on a runway require wings and undercarriage. These typically consume about 9-12% of the landing vehicle mass, which either reduces the payload or increases the size of the vehicle. Concepts such as lifting bodies offer some reduction in wing mass, as does the delta wing shape of the Space Shuttle.

Vertical landings can be accomplished either with parachutes (as with Soyuz) or propulsively. The DC-X is an example of a propulsive lander,[3] and the Falcon 9 rocket is the first orbital rocket to vertically land its first stage on the ground. This typically requires about 10% of the total first stage propellant, reducing the payload that can be carried due to the rocket equation.[4]

Reusable stages weigh more than equivalent expendable stages. This is unavoidable due to the supplementary systems, landing gear and/or surplus propellant needed to land a stage. The actual mass penalty depends on the vehicle and the return mode chosen.[5]

McDonnell Douglas DC-X used vertical takeoff and vertical landing

NASA started the Space Shuttle design process in the late 1960s, with the vision of creating a fully reusable spaceplane using a crewed fly-back booster for the 1970s. This design proved too expensive and complex to develop in time, therefore the design was scaled back to use reusable solid rocket boosters and an expendable external tank.[6][7] The Shuttle proved much more expensive to operate over its 30 year lifetime than an expendable launch system would have been.

In 1986 President Ronald Reagan called for an air-breathing scramjet National Aerospace Plane (NASP)/X-30. The project failed due to severe technical issues and was canceled in 1993.[8]

In the 1990s the McDonnell Douglas Delta Clipper VTOL SSTO proposal progressed to the testing phase. The DC-X prototype demonstrated rapid turnaround time and automatic computer control.

In mid-1990, British research evolved an earlier HOTOL design into the far more promising Skylon design, which remains in development.

From the commercial side, Rocketplane Kistler and Rotary Rocket attempted to build reusable privately developed rockets before going bankrupt.

NASA proposed risky reusable concepts to replace the Shuttle technology, to be demonstrated under the X-33 and X-34 programs, which were both cancelled in the early 2000s due to rising costs and technical issues.

Scaled Composites SpaceShipOne used horizontal landing after being launched from a carrier airplane

The Ansari X Prize contest was intended to develop private suborbital reusable vehicles. Many private companies competed, with the winner, Scaled Composites, reaching the Kármán line twice in a two-week period with their reusable SpaceShipOne.

In 2012, SpaceX started a flight test program with experimental vehicles. These subsequently led to the development of the Falcon 9 reusable rocket launcher.[9]

On 23 November 2015 the New Shepard rocket became the first Vertical Take-Off/Landing (VTOL) sub-orbital rocket to reach space by passing the Kármán line (100 km or 62 mi), reaching 329,839 ft (100,535 m) before returning for a propulsive landing.[10][3]

SpaceX achieved the first vertical soft landing of a reusable orbital rocket stage on December 21, 2015, after helping send 11 Orbcomm OG-2 commercial satellites into low Earth orbit.[11]

The first Falcon 9 second flight occurred on 30 March 2017.[12] SpaceX now routinely recovers and reuses their first stages, with the intent of reusing fairings as well.[13]

As of May 2020, the only operational reusable orbital-class launch systems are the Falcon 9 and Falcon Heavy, the latter of which is based upon the Falcon 9. SpaceX is also developing the fully reusable Starship launch system,[14] and Blue Origin is developing its own New Glenn reusable orbital rocket.

Falcon Heavy side boosters landing during 2018 demonstration mission.