US Space Force reveals sixth mission for mysterious X-37B space plane

The United States Space Force has announced intentions to launch a sixth mission with its mysterious X-37B "space plane." The fifth mission (OTV-5), which was classified, ended successfully in late October 2019 and returned to Earth after 780 days, a record that broke its previous 718-day mission that ended in 2017. In an announcement last week, the US Space Force said that the OTV-6 mission will launch on May 16, marking a milestone in the effort.

The X-37B belongs to the US Air Force, but the US Space Force has been tasked with launching it, managing its orbit operations, and returning it to Earth after each mission ends. The space plane is autonomous and looks like a smaller version of the Space Shuttle; it features a payload bay and has previously carried secret payloads.

Overall, the space plane was developed to give the US government a reusable spacecraft for future space flight and for operating experiments in space that can be returned back to Earth. The spacecraft is solar powered and fairly mysterious — the original X-37 program launched back in 1999, later being transferred from NASA to DARPA in 2004.

That program eventually spawned the X-37B program, which is being operated by the US Air Force Rapid Capabilities Office alongside Space Force. In its announcement last week, the USAF said the OTV-6 mission will be the first to use the space plane's service module for hosting experiments.

The mission will be used as an opportunity to launch the US Air Force Academy-developed FalconSat-8 satellite. That satellite itself carries five experimental payloads that will be operated by the USAF Academy. Joining the FalconSat-8 will be a couple of experiments from NASA, as well. It's unclear how long the US Space Force anticipates the sixth mission will last.