缩尺复合体公司型号339 太空船2号（SpaceShipTwo）是一部亚轨道飞机，以携带太空游客。这飞机是由民间的太空船公司，一家由缩尺复合体公司及维珍集团共同的合资企业开发，是Tier 1b计划的一部分。飞机于2009年9月7日于加洲Mojave Air and Space Port正式向公众宣布。维珍银河太空线计划于2011年经营共五架次飞机队的载客私人太空飞行服务，票费需20万美元。

起飞由太空船载机白色骑士2号搭载，在18千米高空将太空船2号抛下，然后火箭助推器点火，舱内人员穿增压服抵抗重力加速度。达到3.3倍音速后，火箭发动机关闭，太空船2号依靠惯性爬升至110千米处，然后进行自由落体。在火箭发动机关闭到再入大气层之间大约会经历4.5分钟的失重状态。下降时采用与太空船1号相同的减速系统。

The Scaled Composites Model 339 SpaceShipTwo (***) is an air-launched suborbital spaceplane type designed for space tourism. It is manufactured by The Spaceship Company, a California-based company owned by Virgin Galactic.

SpaceShipTwo is carried to its launch altitude by a Scaled Composites White Knight Two, before being released to fly on into the upper atmosphere powered by its rocket engine. It then glides back to Earth and performs a conventional runway landing. The spaceship was officially unveiled to the public on 7 December 2009 at the Mojave Air and Space Port in California. On 29 April 2013, after nearly three years of unpowered testing, the first one constructed successfully performed its first powered test flight.