A Dutch photographer has managed to track and photograph a top-secret US military space plane from his backyard.
The experimental X-37B unmanned space plane, which resembles a miniature space shuttle, has been in orbit above the earth since September 2017.
One of two in the Air Force fleet, the vessel's mission is to "perform risk reduction, experimentation and concept-of-operations development for reusable space vehicle technologies", the Air Force has said without providing details.
Ralf Vandebergh told livescience.com he had been tracking the X-37B craft for months. After catching a glimpse, but no photos, of the plane in May, he finally secured some images in late June and early July - though no official sources have verified his sighting.
"When I tried to observe it again [in] mid-June, it didn't meet the predicted time and path," Vandebergh explained. "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."
The images he obtained and posted to his Twitter account are blurry, which is to be expected from a set up in Vandebergh's garden and from a distance of hundreds of kilometres.
"It is really a small object, even at only 300 kilometers altitude, so don't expect the detailed level of ground-based images of the real space shuttle," Vandebergh said.
However, these images still far exceeded Vandebergh's expectations.
"We can recognise a bit of the nose, payload bay and tail of this mini-shuttle, with even a sign of some smaller detail," he said.
The Secure World Foundation, a nonprofit group promoting the peaceful exploration of space, says the secrecy surrounding the X-37B suggests the presence of intelligence-related hardware being tested or evaluated aboard the craft.