Mir orbiting Earth. Photo: NASA

The two cosmonauts aboard the Russian space station Mir will pack up and return to Earth tonight after a successful mission to reactivate the 14-year old outpost.

Sergei Zalyotin and Alexander Kalery began their tour-of-duty on April 4 when they were launched into space atop a Soyuz rocket from Baikonur Cosmodrome in Kazakhstan. The mission was commercially-funded by MirCorp.

Later today the duo will board their Soyuz TM-30 capsule, closing the hatches to again leave Mir vacant. Undocking is slated to occur at 2122 GMT (5:22 p.m. EDT).

A four-minute deorbit burn is expected to begin at 2352:02 GMT (7:52:02 p.m. EDT) to slow the Soyuz from orbit, and sending the craft on a fiery plunge through Earth's atmosphere.

The parachute-controlled touchdown of the capsule should occur around 0043:50 GMT Friday (8:43:50 p.m. EDT tonight) about 46 km from the town of Arkalyk, Kazakhstan.

MirCorp's statistics show upon landing, the cosmonauts will have spent 73 days (approximately 1,744 hours) onboard Mir and approximately 53 hours in the Soyuz TM-30 vehicle. While onboard the station, the cosmonauts will have orbited the Earth 1,110 times, with an additional 34 orbits in the Soyuz.

The crew spent their final full day aboard Mir on Wednesday stowing experiment equipment and readying the station to remain abandoned until MirCorp can launch a new team of cosmonauts.

Officials reported Zalyotin configured the life support system for autonomous operation, and then deactivated the Kristall module. Kalery, meanwhile, disassembled the Orangereya experiment, which has seen the successful growth of red mustard, Chinese cabbage and other plants. He photographed the plants, then stowed the film and plant samples for the return to Earth.