The Space Shuttle is a spacecraft that cannot be launched nor re-entered, found near X = 635 Y = 1915 in Mission 30, and in Sandboxes made after said mission. Note that the shuttle will have to be rescued again inside the sandbox. It is best to do this first, otherwise the shuttle will become very hard to locate.
It looks like a NASA space shuttle (hence its name), and has a docking port on its left side near the cockpit. It can carry eight units of cargo, of which at least one must be taken up by a Battery.