China’s defunct Tiangong-1 space station’s collision course with earth will see the 18,000 pound structure reenter the atmosphere sometime around April 1st (give or take three days) – but as for where, it’s still too early to tell.

The Tiangong-1 was China’s first prototype space station. Launched in 2011 to serve as both a manned laboratory and as a testbed for orbital docking and rendezvous technologies the Chinese space program was continuing to develop at the time. After a two year operational service life, the Tiangong-1 was originally expected to deorbit in 2013, but remained until March 21st, 2016 when China admitted that they had lost their telemetry link with the space station, though it wasn’t until September of that year that the Chinese government was forced to acknowledge that they had, in fact, lost complete control over the platform.

China’s space-based endeavors, managed by the China National Space Administration, are not a civilian enterprise as seen from NASA, Roscosmos and the European Space Agency. Instead, China’s space program, which is only the third in history to successfully put an astronaut in orbit, can be better characterized as a joint venture between China’s military and their Commission on Science, Technology, and Industry for the National Defense. This distinction makes their program far less transparent than other national programs; hence their reluctance to acknowledge their loss of control of the platform.

Had China been able to maintain control over the space station, they could have managed its descent into the earth’s atmosphere, dictating the time and location of reentry. However, without any means to manage the nearly 10 tons of materials, the best scientists can do is throw their best arithmetic at it.