CH-47 and X-40A before Free flight 4A. The unpowered X-40A, an 85 percent scale risk reduction version of the proposed X-37, proved the capability of an autonomous flight control and landing system in a series of glide flights at Edwards. Ultimately, the unpiloted X-37 is intended as an orbital testbed and technology demonstrator, capable of landing like an airplane and being quickly serviced for a follow-up mission.
