The US military’s secretive X-37B robot spaceplane has blasted off from Florida on its seventh mission, the first launched atop a SpaceX Falcon Heavy rocket capable of delivering it to a higher orbit than ever before. As on previous missions, there are no humans on board the reusable plane, which resembles a mini space shuttle and carries classified experiments. The Falcon Heavy, composed of three rocket cores strapped together, took off from NASA’s Kennedy Space Center at Cape Canaveral more
