【可重复使用的航天器】
可重复使用航天器，顾名思义，是可重复使用的航天器，其设计须考虑重复发射、轨道、脱轨、大气层再入。
可重复使用航天器的例子有太空飞机、航天飞机、航天飞机轨道器、逐梦者太空飞机、龙飞船的宇宙飞船。
此类系统的灾难有：挑战者号航天飞机灾难、哥伦比亚号航天飞机灾难。
== 设计 ==
=== Atmospheric entry ===
Reusable spacecraft include mechanisms to deorbit and reenter the atmosphere in a controlled fashion. For this purpose, the 航天飞机 included 航天飞机轨道机动系统, and the 龙飞船 included its own engines, used for deorbiting. Deorbiting slows the spacecraft down, lowering its perigee to inside the atmosphere where the vehicle descends to Earth.
As a rough rule of thumb, 15% of the landed weight of an atmospheric reentry vehicle needs to be 防热盾ing.
航天飞机隔热系统s (TPS) can be made of a variety of materials, including reinforced carbon-carbon and 再入.  Historically these materials were first developed on ICBM 多目标重返大气层载具s. However, the requirements of reusable space systems differ from those of single use reentry vehicles, especially with regards to 防热盾 requirements. In particular the need for durable high 发射率 coatings that can withstand multiple thermal cycles constitutes a key requirement in the development of new reusable spacecraft. Current materials for such high 发射率 coatings include transition metal disilicides.
Ablative heat shields are reliable, but they can only be used once, and are heavy. Reinforced carbon-carbon heat tiles like those used on the Space Shuttle are fragile, and this was proved on the Space Shuttle Columbia disaster. Making a resistant yet lightweight and effective heat tile poses a challenge. The LI-900 material was used on the Space Shuttle.
===Landing and refurbishment===
Spacecraft that land horizontally on a runway require wings and undercarriage. These typically consume about 9-12% of the spacecraft mass,date=July 2020 which either reduces the payload or increases the size of the spacecraft. Concepts such as 举升体 offer some reduction in wing mass,date=July 2020 as does the 三角翼 shape of the 航天飞机轨道器.
垂直起降 (火箭) can be accomplished either with parachutes or propulsively. 龙飞船 was an example of 宇宙飞船 with parachute reusability. Its derivative, 龙飞船2号, was originally intended to propusively land on land. However, such concept of reusability was canceled in 2017 and now Dragon 2 uses parachutes to land in the ocean.
After the spacecraft lands, it may need to be refurbished to prepare it for its next flight. This process may be lengthy and expensive, taking up to a year. And the spacecraft may not be able to be recertified as human-rated after refurbishment. There is eventually a limit on how many times a spacecraft can be refurbished before it has to be retired, but how often a spacecraft can be reused differs significantly between the various spacecraft designs.
== 可重复使用航天器列表 ==
=== US和欧洲太空总署===
==== 活跃 ====
*太空船2号
*龙飞船2号
**Crew Dragon
**Cargo Dragon
*新雪帕德火箭
*X-37试验机
==== 发展阶段 ====
比较图
*SpaceX星舰
*逐梦者太空飞机
*波音星际航线
*猎户座飞船
*Space Rider
*SUSIE
==== 已退役 ====
* X-15试验机
* 双子座计划
** SC-2
*航天飞机轨道器
**发现号太空梭
**挑战者号太空梭（挑战者号航天飞机灾难）
**哥伦比亚号太空梭（哥伦比亚号航天飞机灾难）
**企业号太空梭（从未飞过太空）
**亚特兰提斯号太空梭
**奋进号太空梭
*龙飞船
==== 已取消 ====
*X-20试验机
*赫尔墨斯号航天飞机
=== 俄罗斯 苏联 ===
* VA spacecraft
*暴风雪太空梭计划轨道飞行器
**暴风雪号穿梭机
**小鸟号太空梭（从未飞过太空）
**2.01（从未飞过太空）
**2.02（从未飞过太空）
**2.03（从未飞过太空）
==== 发展阶段 ====
*鹰宇宙飞船
==== 已取消 ====
*Kliper
*MAKS
=== 其它 ===
*新一代载人飞船
*RLV-TD
==== 发展阶段 ====
*阿凡达太空梭
==== 已取消 ====
*HOPE-X