Europe's automated cargo craft makes final service call
BY STEPHEN CLARK
Posted: August 12, 2014
Europe's Automated Transfer Vehicle made its final cargo delivery to the International Space Station on Tuesday, completing a smooth computer-controlled docking to resupply the orbiting laboratory with 7.3 tons of fuel, water, experiments and provisions.
With a glacial closing rate of about 2 inches per second, the 20-ton supply ship linked up with the space station's Zvezda service module at 1330 GMT (9:30 a.m. EDT) as the spacecraft sailed 260 miles over southern Kazakhstan at a velocity of more than 17,000 mph.
Lasers and radars guided the ATV for the final phase of the rendezvous, which completed a two-week journey after the craft's July 29 launch aboard an Ariane 5 rocket from French Guiana.
The ATV's cargo complement includes crew clothing, food, rocket fuel, water and experiments, including fish for a Japanese aquatic investigation. Soy sauce, coffee and tiramisu are also on-board.
The space station's crew will open the hatches leading to the ATV on Wednesday. After ensuring the spaceship's air is clean, cargo unloading is scheduled to begin Thursday.
The massive supply load is the biggest delivered to the space station since the last space shuttle mission in 2011. No other vehicle is capable of taking up so much cargo to the outpost.
Named for Georges Lemaitre, the Belgian priest and physicist behind the Big Bang theory, the cargo spacecraft is the last in a line of five European resupply freighters, a 3 billion euro ($4 billion) program that started with studies in the late 1980s before ESA committed to the spaceship's development.
About 14,500 pounds of cargo and fuel was delivered with the ATV's docking Tuesday.
The cargo complement includes 1,896 pounds of propellant to be pumped inside the Russian Zvezda service module, 1,858 of fresh water, 220 pounds of air and pure oxygen, and more than 5,900 pounds of dry cargo.
When docked to the aft end of the space station's Russian segment, the ATV will raise the lab's altitude and maneuver it out of the way of space junk.
The largest piece of hardware aboard ATV 5 is an electromagnetic levitator for ESA's Material Science Laboratory inside the Columbus module. The device will melt down metallic samples for research in material thermodynamics, according to ESA.
An upgrade for NASA's robotic satellite servicing testbed on the space station was also carried by the ATV. An articulating borescope inspection tool will be added to the satellite servicing experiment to test in-space inspection capabilities.
With the five ATVs, Europe sent up 31,446 kilograms, or 69,327 pounds, of cargo, fuel, water and air to the space station, according to Thomas Reiter, head of ESA's human exploration and operations directorate.
"Georges Lemaitre is the last ATV, six years after the launch of the first, which was in March 2008," said Jean-Jacques Dordain, ESA's director general. "Six years have gone by in the meantime, but the ATV is, and will remain for a long time to come, a unique space vehicle. It's the most complex vehicle that ESA and European industry have ever developed and produced. It's both a launcher and a satellite. It's both automatic and man-rated. It's capable of unparalleled accuracy and controlled atmospheric re-entry."
ESA is retiring the ATV in favor of a new program to design and build the service module for an unmanned test flight of NASA's Orion multipurpose crew vehicle set for launch at the end of 2017.
"To say it very bluntly, if Europe had not done ATV, the service module for [Orion] MPCV would have been a no go," said Bart Reijnen, head of orbital systems and space exploration at Airbus Defence and Space.
Officials said they wished to put engineers to work on developing a new spacecraft instead of building more ATVs. Cargo deliveries to the space station will continue with a fleet of supply vehicles from the United States, Russia and Japan.
The U.S. Dragon and Cygnus cargo craft, along with Japan's H-2 Transfer Vehicle, can carry up larger experiments than the ATV, which attaches to the Russian segment of the space station with a smaller passageway than NASA's modules.
Russia's Progress spacecraft delivers propellant, but in smaller quantities than the ATV.
But the ATV is the only cargo craft to do it all.
The ATV missions were part of a barter agreement between ESA and NASA. The resupply capabilities offered by the ATV paid Europe's share of the space station's operating costs through 2017.
ESA's payment for the station's operating expenses from 2017 through 2020 will be paid with the provision of the Orion spacecraft's service module, which is valued at approximately 450 million euros, or about $600 million.
At the end of the ATV 5 mission, currently scheduled for January or February, the ATV will undock from the space station's Zvezda service module with trash and waste. Like the previous European cargo ships, the ATV 5 mission will plunge back into the atmosphere, destroying itself and the garbage inside, clearing precious room on the space station for fresh experiments and cargo.
But NASA and ESA officials have devised a plan to change the re-entry trajectory to collect data on how the ATV responds when it falls into the atmosphere, helping engineers validate computer models to predict how the space station will re-enter at the end of its mission as a crewed orbiting research laboratory.
Pending final approval from safety officials, the shallow re-entry profile would occur over the uninhabited South Pacific Ocean.
The ATV also carries an internal camera to record and transmit imagery of the re-entry from inside the spaceship's pressurized module.
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