Not much is known regarding the missions being conducted by the Air Force’s X-37B Orbital Test Vehicle (OTV) as it currently orbits Earth. Launched on 5 March this past spring, 30 November marked its 270th consecutive day in space which was considered to be its maximum duration possible before landing itself. This second mission was planned for 9 months, which is any day now. One of the items making a mission of this length possible is the deployable solar panel which was made public during the OTV’s initial mission in 2010
NASA had originally started the X-37 program in 1999 with the intent to build two vehicles: one to test the approach and landing capabilities of the craft and the other to serve as the orbital test vehicle. On 2004 the program was transferred to DARPA who, with the help of the Air Force Research Lab, went on to build the first vehicle, subsequently validating its flight characteristics. DARPA ended its program in 2006 where then the Air Force Rapid Capabilities Office (RCO) picked up the program, going on the build the OTVs.
Boeing serves as the prime contractor for the building of the X-37B OTVs, two of which have been built thus far. OTV-1 launched from Cape Canaveral Air Force Station atop an Atlas V booster on 22 April, 2010, and orbited Earth for a little over 224 days before landing itself autonomously at Vandenberg AFB on 3 December. The OTV is a little over 29 feet long with a 24 foot wingspan and stands at 9.5 feet tall. The craft also has a cargo bay with doors that can open while in space similar to that of the space shuttle.
Officially, the OTV is a test bed for various technologies such as navigation and various other guidance systems as well as physical structures such as reusable insulation to support re-entry. Another item listed as being tested is autonomous orbital flight. This means that the X-37B can be launched and once on orbit conduct a preplanned mission without operator intervention and safely land itself once its mission is complete. Given that the X-37B has been so heavily shrouded in secrecy, it is this last attribute that has garnered a great deal of attention. Many speculate that payloads have been developed to be used for eavesdropping, either through imagery or signals collection, which could easily be loaded into the X-37B’s cargo bay depending on the specific needs of a particular mission. Others view it as a more utilitarian asset such as a ferry to space in support of the International Space Station or to service other satellites. Boeing has even discussed an X-37C variant that could carry up to seven astronauts into space.