Japan’s sixth HTV supply ship departed the International Space Station on Friday and headed for a destructive re-entry over the South Pacific with trash and disused batteries from the research lab, but engineers will first use the spacecraft for a pioneering experiment to investigate a new way to remove space junk from orbit.

Veteran Russian cosmonaut Gennady Padalka, more than three months into his fifth trip into orbit, has passed countryman Sergey Krikalev’s mark of 803 days of cumulative time in space.

Taking advantage of available astronaut time, the International Space Station’s crew will cast off the commercial Orbital ATK Cygnus freighter on Sunday morning nearly six weeks ahead of schedule.