The X-37B, the US Air Force’s reusable space plane, landed at NASA’s Kennedy Space Center yesterday.

The unmanned X-37B was in orbit for 718 days before the landing. Reports say it caused sonic boom which could be heard across state.

The Boeing-built space plane blasted off in May 2015 from Cape Canaveral air force station aboard an Atlas 5 rocket built by United Launch Alliance, a partnership between Lockheed Martin and Boeing.

The X-37B, one of two in the Air Force fleet, conducted unspecified experiments while in orbit. It was the fourth and lengthiest mission so far for the program, managed by the Air Force Rapid Capabilities Office.

“The landing of OTV-4 marks another success for the X-37B program and the nation,” said Lt. Col. Ron Fehlen, X-37B program manager. “This mission once again set an on-orbit endurance record and marks the vehicle’s first landing in the state of Florida. We are incredibly pleased with the performance of the space vehicle and are excited about the data gathered to support the scientific and space communities. We are extremely proud of the dedication and hard work by the entire team.”

The orbiters “perform risk reduction, experimentation and concept-of-operations development for reusable space vehicle technologies”, the Air Force has said, without providing details. The cost of the program is also classified.

New space technologies

“Today marks an incredibly exciting day for the 45th Space Wing as we continue to break barriers,” said Brig. Gen. Wayne Monteith, the 45th SW commander. “Our team has been preparing for this event for several years, and I am extremely proud to see our hard work and dedication culminate in today’s safe and successful landing of the X-37B.”

“The hard work of the X-37B OTV team and the 45th Space Wing successfully demonstrated the flexibility and resolve necessary to continue the nation’s advancement in space,” said Randy Walden, the director of the Air Force Rapid Capabilities Office. “The ability to land, refurbish, and launch from the same location further enhances the OTV’s ability to rapidly integrate and qualify new space technologies.”

The Air Force is preparing to launch the fifth X-37B mission from Cape Canaveral later in 2017.

Read more on The Guardian and the US Air Force website