Third European Cargo Tug Docks with International Space Station
PARIS — Europe’s 20,000-kilogram ATV-3 cargo freighter on March 29 successfully concluded an automatic docking with the international space station, where it will supply food, water, fuel and other supplies during a five-month visit.
The docking maneuver, which was webcast from the ATV control center at the Toulouse, France, facility of the French space agency, CNES, showed the vehicle slowly closing in on the 450,000-kilogram station. ATV-3, the third of a planned five Automated Transfer Vehicles that the European Space Agency (launched March 23 aboard a European Ariane 5 rocket from Europe’s Guiana Space Center on the northeast coast of South America.) is providing NASA, was
The two remaining ATVs are scheduled for launch in 2013 and 2014. Once they have completed their missions, ESA will have repaid NASA for Europe’s 8.3 percent share of the station’s maintenance costs through 2016.
European governments now must decide, in concert with NASA as the space station’s general contractor, how Europe will compensate for the estimated 450 million euros ($600 million) in station charges it will owe NASA for the period between 2017 and 2020. The station’s partners — Russia, Japan and Canada in addition to Europe and the United States — have agreed to keep the orbital complex in service through 2020, and perhaps beyond.
ESA governments are expected to decide in November, following negotiations with NASA, on what “barter element” will replace ATV. Current possibilities include using some of the features of ATV to perform other tasks in low Earth orbit.
“The technologies we have demonstrated in operational conditions with the ATVs have a tremendous potential for future human spaceflight and exploration missions,” ESA Human Spaceflight and Operations Director Thomas Reiter said in a statement after the docking.
As was the case with the previous two ATV flights, ATV-3, named Edoardo Amaldi after the Italian physicist, conducted its final approach to the station in all-automatic mode using its optical sensors. These sensors, provided by Jena Optronik GmbH of Jena, Germany, are switched on once the ATV has closed to 250 meters from the ATV docking port on Russia’s Zvezda module at the station.
Once within 20 meters of the station, the ATV goes into a hold position to assure that all systems are OK for the final approach. As programmed, ATV-3’s final few meters to docking were conducted at a relative speed of 7 centimeters per second.
Jena Optronik said its telegoniometer and videometer rendezvous and docking sensors are also used aboard Japan’s H-2 Transfer Vehicle. As with ATV, the Japan Aerospace Exploration Agency uses its cargo carrier to offset station charges.
ESA said the sensors permit ATV to approach the station with a precision of 6 centimeters.
ESA’s Artemis data-relay satellite, in geostationary orbit at 21.4 degrees east, was used to provide telemetry between ATV-3, the space station and the ATV control center in Toulouse.
Once its fuel and cargo have been unloaded, ATV-3 will be filled with garbage, de-docked on Aug. 27 and sent on a controlled destructive re-entry into Earth’s atmosphere over the southern Pacific Ocean, with a predetermined re-entry corridor cleared of maritime traffic.