TABLE 2.2 Major Reusable Booster System (RBS)/Reusable Launch Vehicle Features
|Program||Customer||Crewa||Reused Elements||Ascent Concept||Final Orbit||Upper Stage Reuse||Key Elements at TRL<6 at Program Start|
|Space shuttle||NASA||Y||Orbiter and solidsb||TSTOc||LEO||Y||Reusable Solids Staged Combustion Engine Reentry TPS VTHL RTLS Ground Processing Operations|
|National AeroSpace Plane (X-30)||Air Force/ NASA||Y||Total vehicle||SSTO||LEO||Y||Airbreathing propulsion system|
|Lockheed Martin X-33||NASA||Y||Total vehicle||SSTO||LEO||Y||SSTO Linear Aerospike Engine Thrust Modulated TVC EMA|
|Kistler K-1||Multiple||Y||1st and 2nd stages||TSTO||LEO to GEO||Y||Reusable TSTO Land Recovery|
|SpaceXd Falcon 9||Multiple||Y||1st and 2nd stages||TSTO||LEO to GEO||N|
|RBS||Air Force||N||1st stage only||TSTOe||LEO to GEO||N||Reusable LO2/RP-1 ORSC rocket engine Rocketback Maneuver RTLS Ground Processing Operations|
a Booster vehicle designed for potential transport of crew.
b Solids recovered down range.
c Main propellant tank expended, solids recovered downrange.
d Present Falcon 9 described. A SpaceX RTLS concept in development.
e Critical subsystems/processes not demonstrated at flight conditions.
NOTE: EMA, electro-mechanical actuator; GEO, geosynchronous Earth orbit; LEO, low Earth orbit; ORSC, oxygen rich, staged combustion; RTLS, return to launch site; SSTO, single stage to orbit; TPS, thermal protection system; TRL, technology readiness level; TSTO, two stages to orbit; TVC, thrust vector control; VTHL, vertical takeoff, horizontal landing;