After a three-day delay, the European Space Agency's "Edoardo Amaldi" Automated Transfer Vehicle 3 (ATV-3) undocked from the aft port of the International Space Station's Zvezda service module on Friday (Sept. 28) at 4:44 p.m. CDT (2144 GMT).
Tuesday's initial attempt at undocking the European cargo ship was called off due to a communications error between Zvezda's proximity communications equipment and computers on the ATV. Russian flight controllers resolved the problem, and station program management approved a second undocking attempt.
Expedition 33 flight engineers Yuri Malenchenko and Aki Hoshide, who together closed up the hatches to ATV-3 Monday, monitored its automated departure from a control panel inside Zvezda. Meanwhile, Commander Suni Williams photographed the departing freighter to document the condition of its docking assembly.
ATV-3, now filled with trash and unneeded items, backed away to a safe distance from the orbiting complex after undocking. Once it reaches a distance of about 4,500 miles in front of the station, the European cargo craft will fire its engines twice on Tuesday (Oct. 2), to send it into the Earth's atmosphere for a planned destructive re-entry that evening.
As ATV-3 plunges back into the atmosphere, the Re-Entry Breakup Recorder
that Hoshide installed in the vehicle will collect and transmit engineering data to enhance the efficiency of spacecraft designs and minimize the hazards to people and property on the ground even in the case of an uncontrolled re-entry for future cargo ships.
"Edoardo Amaldi," named for an Italian physicist regarded as one of the fathers of European spaceflight, delivered 7.2 tons of food, fuel and supplies to the orbiting complex after docking on March 28. The fourth ATV, named "Albert Einstein," is slated to launch in April 2013.
More than 32 feet long (9.75 meters) — about the size of a traditional London double-decker bus — the ATV is the largest and heaviest vehicle that provides cargo resupply for the station.