The mysterious X-37B, an uncrewed spaceplane belonging to the US Air Force, may soon come back to Earth after spending over 630 days orbiting our planet.

The news was reported by NASA Spaceflight, a spaceflight news source not affiliated with the space agency. One week ago, they discussed how conditions were ideal for a landing at the Kennedy Space Center, and since there was some Air Force activity in Florida, people began to wonder if the landing was going to happen.

However, Captain Annmarie Annicelli, an Air Force spokeswoman at the Pentagon, told Florida Today that such claims were unfounded. "The X-37 is still on-orbit," she said. "The program is conducting a regularly scheduled exercise this week."

The mission, known as OTV-4, is semi-classified, so while we know the broader facts about the X-37B, there are still many details that are kept confidential. The mission was launched on a vertical rocket from the Cape Canaveral Air Force base on May 20, 2015, and just like the Space Shuttle, it lands horizontally.

This is the fourth test for the program, which was first designed for NASA, and the second orbital flight for this particular spaceplane. The X-37B is 9 meters (29 feet) in length and has a wingspan of 4.55 meters (15 feet). It is also solar powered, which allows for long orbital periods. The longest mission in the program lasted 675 days, from December 11, 2012, to October 17, 2014.

The Pentagon says it will announce when the spaceplane is back on the ground. Until then, we are left with our rekindled wonder about this intriguing mission.

^{X-37B. US Air Force/Michael Stonecypher}

[H/T: NASA Spaceflight]