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US space plane on secret mission breaks record for days in orbit

Next week will mark two years in orbit for the mini-shuttle, but what is it doing up there?

An uncrewed U.S. Air Force space plane has just broken the record for time spent in orbit. What it's specifically been doing up there has been kept a tightly guarded secret.

The X-37B, which looks like a small space shuttle, has spent 719 straight days in orbit and counting, according to The Washington Post and ScienceAlert. It launched on September 7, 2017.

This is its fifth orbital mission. The previous one was reportedly in space for 717 days, 20 hours and 42 minutes. The first four missions combined stayed in orbit for 2,085 days, according to the Air Force.

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So, what's it been doing? Go to the Air Force website and you'll see that the description of its mission is short on specifics.

“The primary objectives of the X-37B are twofold: reusable spacecraft technologies for America’s future in space and operating experiments which can be returned to, and examined, on Earth," according to the Air Force.

An Air Force spokesperson has also reportedly said it allows experiments in space to be conducted for long periods and then returned to Earth for study.

With details lacking, that opens it up to speculation, and there have been plenty of theories including:

  • Testing an experimental propulsion system that uses little-to-no fuel
  • Orbital surveillance
  • Weapons research
Credit: US Air Force
In a testing procedure, the X-37B Orbital Test Vehicle taxis on the flightline March 30, 2010, at the Astrotech facility in Titusville, Fla.

Vehicle facts (Source: U.S. Air Force)

  • Contractor: Boeing
  • Height: 9 feet, 6 inches
  • Length: 29 feet, 3 inches
  • Wingspan: 14 feet, 11 inches
  • Launch Weight: 11,000 pounds
  • Power: Gallium Arsenide Solar Cells with lithium-Ion batteries
  • Launch Vehicles: Atlas V and SpaceX Falcon 9