The mini-shuttle X-37B blasted off atop an Atlas V 501 rocket from Cape Canaveral. The launch seems to have gone well but ULA (United Launch Alliance), which manages it, broadcat the images providing information on the progress of the operations just for a few minutes. That’s because the mission of this spaceplane is carried out by the US Air Force and is partially covered by military secret.
The X-37B resembles a small Space Shuttle and that’s not accidental because the project is derived from it. Initially, it was developed jointly by NASA and US Air Force but in 2004 became an entirely military project with the result that the information about it are classified. In 2006 the current variant was introduced.
With the X-37B, the US Air Force has a reusable spaceplane that, like the Space Shuttle, can land like a normal airplane. However, between the two shuttles there are also important differences. The X-37B is fully automated and can stay in orbit for very long times.
The two X-37Bs manufactured so far carried out a total of three missions. The first, OTV-1, started on April 22, 2010 and ended on December 3, 2010 for a total of 224 days in flight for the first X-37B. The second, OTV-2, started on March 5, 2011 and ended on June 16, 2012 for a total of 469 days for the second X-37B. The third, OTV-3, started on December 11, 2012 and ended on October 17, 2014 for a total of 675 days.
Since this is a military mission, the information on the operations that are carried out in orbit are limited. Over the years, there have been various speculations on the possible use of the X-37B as a spy satellite and to test technologies related to weapon development.
If the OTV-4 mission that just begun, also indicated as AFSPC-05 by ULA, some experiments was revealed. For example, an ion propulsion system will be experimented that utilizes the Hall effect to accelerate the propellant using an electric field. Ion engines have achieved considerable development in recent years and the US Air Force also wants to use them on its satellites because they require much less propellant.
As secondary payload, the rocket launched some nanosatellites of CubeSat class, based on cube-shaped units of 10 cm (4″) side. Among them there’s a prototype of The Planetary Society’s solar sail LightSail called LightSail-A that will be used to test the on-board systems before the mission that is raising funds.
There’s also the USS Langley, a small space Internet server of the US Navy Academy. It aims to test the use of a server that uses standard hardware and software such as the BeagleBoard and the Linux operating system to provide connections between clients via the TCP/IP protocol without a ground network.
Because of the classified nature of this launch, we’re going to get some information about its success only if and when the US Air Force sees fit. Definitely we will be given information about what happened to at least some of nanosatellites.