Cygnus cargo ship OA-4 "SS Deke Slayton II" approaches the ISS. Credit: Roscosmos.
Early this morning, the International Space Station received a large package from Earth carrying supplies and experiments. Orbital ATK's Cygnus cargo spacecraft reached the station after careful maneuvering by ground controllers following a two and a half day flight mission from Earth. The last attempt to send a Cygnus cargo ship to the ISS failed last year when the company's new Antares booster exploded at launch, destroying the ship and the pad in a ball of fire. SpaceX's Dragon was destroyed in its last attempt. SpaceX plans to launch again soon after correcting booster problems. While the Antares is under further review and correction, Orbital ATK is using the Atlas V booster to reach orbit.
Cygnus spacecraft on the Atlas V rocket at pad SLC-41 at the Cape Canaveral Air Force Station in Florida. Credit: NASA.
The rocket took off Sunday at 4:44 pm Eastern from Space Launch Complex 41 under the care of the United Launch Alliance (ULA) which manages Atlas V flights with NASA. The spacecraft is an improved cargo vessel allowing over 7,700 pounds of supplies to reach the station. The craft was the heaviest object yet to be launched by the Atlas V rocket, weighing over 16,000 pounds.
Current locations of docked spacecraft at the ISS. NASA.
After the Cygnus docked at 7:14 am Eastern, astronauts started the process of equalizing pressures and making sure all spacecraft systems are set for the stay to the end of January. They will open the hatch tomorrow and begin transferring the equipment and supplies. Meanwhile, astronauts are also preparing for half the crew to leave on Friday to return to Earth.