主题：【原创】“X37B”是战略平衡破坏者？ -- 瑞士

虽然和我的贴子有点出入，但大意上相同，建议大家看看

我也在美国网站上查找过，发现美国保密做的很好，细节非常少。

希望下面这个网页对你有帮助

外链出处

目前美国对X37B做的比较公开，但HTV-2因为资料非常少，就其外型来看，应该是采用乘波体设计，另外使用超燃发动机。快速机动的HTV-2和长期在太空巡航的X37B形成互补作用。

After a Phase I evaluation of four competing CAV/HTV design proposals, Lockheed Martin received the sole Phase II contract in August 2004 to develop and build the HTVs for the Falcon program. The initial HTV design (HTV-1) was planned to be flight tested using an existing booster in September 2007, and was to reach a speed of Mach 19 at 30-45 km (19-28 miles) altitude. However, in May 2006 the construction of two HTV-1 vehicles was cancelled because subcontractor C-CAT had severe problems with delamination of the curved leading edges of the vehicle's aeroshell. The Falcon program will instead proceed directly to the HTV-2 (q.v. below).

Image: USAF/DARPA

HTV-1

Phase III of the Falcon program, originally planned to run from 2007 to 2010, is going to further develop the HTV and integrate it with the SLV. The second and third generation HTV designs (HTV-2 and HTV-3) are to incorporate further improved aerodynamic configurations, thermal protection systems, guidance, navigation and control systems. The vehicles are going to be about 3.5-4.5 m long and weigh about 900 kg. HTV-1 through -3 designs have an increasingly "waverider-like" shape for increased L/D (lift/drag), increasing flight duration and re-entry cross range. HTV-2 will be an expendable Mach 20+ design, but HTV-3 will be a fully reusable vehicle with a design speed of about Mach 10 at 40000 m (130000 ft). Although HTV-1 and -2 are unpowered designs, it's possible that the reusable HTV-3 will use a scramjet engine. At the time of this writing, two HTV-2 launches (HTV-2a and HTV-2b) are planned for 2009. The boosters will be Orbital Sciences Minotaur IV 4-stage rockets. A launch schedule for HTV-3, and whether this vehicle will actually use one of the Falcon SLV boosters, has not been published so far.

Image: DARPA

DARPA HCV design concept

After completion of Phase III, the Falcon program will be completely transferred to the Air Force.