The Russian Federal Space Agency's (Roscosmos) automated Progress 68 resupply ship lifted off atop a Soyuz rocket at 4:46 a.m. EDT (0846 GMT), beginning a weekend chase of the space station. The cargo ship is scheduled to arrive at the orbiting lab Monday (Oct. 16) at 7:09 a.m. EDT (1109 GMT).
"Liftoff of the 68 Progress resupply craft bound on a two-day journey to the International Space Station," NASA spokesman Rob Navias said during NASA TV commentary. [How Russia's Progress Cargo Ships Work (Infographic)]
Roscosmos initially attempted to launch the Progress 68 mission Thursday (Oct. 12), but an unspecified problem with the Soyuz booster forced flight controllers to abort the liftoff at the last minute. That problem appeared to be resolved Saturday, with the Soyuz flawlessly launching Progress 68 into orbit.
"A perfect ascent to orbit, two days behind schedule but safe and sound nonetheless," Navias said.
The two-day delay, however, meant that Progress 68 was unable to test a novel new flight plan that would deliver the cargo ship to the International Space Station in just 3.5 hours after two orbits of Earth. Instead, it will take a more typical two-day trip to the space station, which requires 34 orbits of Earth, due to the orbital mechanics involved to reach the station, NASA officials have said. Roscosmos can also fly Progress and Soyuz crew capsules to the station on 6-hour flights that orbit Earth four times.
Progress 68 is packed with 5,946 lbs. (2,697 kilograms) of supplies for the space station's six-person Expedition 53 crew. Those supplies include:
- 2,976 lbs. (1,349 kg) of dry cargo like spare parts or science gear,
- 1,940 lbs. (879 kg) of propellant,
- 926 lbs. (420 kg) of water,
- 53 lbs. (24 kg) of air,
- 51 lbs. (23 kg) of oxygen.
Russia's Progress cargo ships are similar in appearance to the country's crewed Soyuz spacecraft, but in place of a central crew module Progress vehicles carry propellant to periodically reboost the space station's orbit.
NASA will broadcast live views of Progress 68's arrival on Monday, beginning at 6:15 a.m. EDT (1015 GMT). You can watch the docking live here, courtesy of NASA TV.