The X-37B OTV 5 is manoeuvering to a higher orbit

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The image above shows the classified robottic X-37B space-plane OTV 5 of the US Air Force, a kind of unmanned mini Space Shuttle, in the sky above my home on August 20. It had manoeuvered in the previous days (probably on August 17 or 18), from an approximately 316 km orbital altitude to 325 km orbital altitude, an orbit raise of ~9-10 km. The video below shows it the next night, passing through Delphinus:





Just two days later, on August 22, OTV 5 was a no-show, indicating another, and major manoeuvre. Three days later, Leo Barhorst found it again, and subsequent observations showed it to had moved into a 387 x 395 km orbit. A total orbital raise of some 75 km in series of manoeuvers spanning a few days.

As can be seen in the diagram below, which is based on amateur tracking data, the orbit of OTV 5 had been rather steady from when Cees Bassa first located it in late April 2018 up to mid August, at an orbital altitude of ~316 km. The orbital raises mid and late August to ~325 km and next to ~391 km could point to a new test regime for the experimental equipment onboard.

click diagram to enlarge

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The X-37B (image: US Air Force). Click to enlarge