Key point: The Pentagon keeps very quiet about the missions and capabilities of the X-37B.
A Dutch skywatcher achieved a rare feat in late June and early July 2019. Using a 10-inch-diameter telescope fitted with a camera, Ralf Vandebergh photographed the U.S. Air Force's secretive X-37B space plane in mid-mission 210 miles over Earth’s surface.
"We can recognize a bit of the nose, payload bay and tail of this mini-shuttle, with even a sign of some smaller detail," Vandebergh told Space.com.
Vandebergh had been hunting for the robotic spacecraft for months and finally managed to track it down in May 2019, according to Space.com reporter Leonard David. But it took a few more weeks to actually photograph the roughly 29-feet-long robotic shuttle.
"When I tried to observe it again [in] mid-June, it didn't meet the predicted time and path," Vandebergh told David. "It turned out to have maneuvered to another orbit. Thanks to the amateur satellite observers' network, it was rapidly found in orbit again, and I was able to take some images on June 30 and July 2, ."
Boeing built at least two X-37Bs for the Air Force in the mid-2000s reportedly at a cost of around a billion dollars apiece. While it looks like a miniature version of NASA’s Space Shuttle, which retired from service in 2011, the X-37B essentially is a small, reusable and maneuverable satellite with a shorter per-mission endurance compared to single-use satellites.
The Air Force describes the X-37B as an “orbital test vehicle,” or OTV.
The X-37B blasted off for its first mission on a United Launch Alliance Atlas rocket in April 2010. Where many satellites can function for up to a decade in orbit, the X-37B’s longest mission as of early 2018 was its fourth, beginning in May 2015. It lasted 717 days.
The X-37B that Vandebergh photographed launched atop a SpaceX Falcon rocket in September 2017. Each X-37B mission reportedly costs around $200 million.
The current mission is the X-37B’s fifth. The X-37B Vandebergh spotted is carrying a so-called Advanced Structurally Embedded Thermal Spreader built by the Air Force Research Laboratory.