Automated Transfer Vehicle
Each ATV is launched by an Ariane 5 from Kourou, French Guiana. After approximately two days of flight it arrives at the ISS and docks automatically to the Russian Service Module Zvezda. The first launch of an ATV (Jules verne) took place on March 9, 2008.
As big as a double-decker bus and with a mass at launch of almost 20 metric tons, the ATV is the biggest and most complex spacecraft Europe has ever flown. It is also the largest spacecraft capable of automatic rendezvous and docking.
DesignThe ATV has three times the capacity of the Russian Progress spacecraft, which it is designed to complement. Like the Progress, it carries both bulk liquids and relatively fragile freight which is stored in a cargo hold kept in a pressurized shirtsleeve environment so that astronauts can have access to it without putting on a spacesuit.
Each ATV weighs 20.7 metric tons at launch and has a cargo capacity of 9 metric tons, including:
Journey to the space station
The crew enter the pressurized part of the ATV. This is similar in layout to the Italian-built cargo modules, known as Multi-Purpose Logistics Modules, which are taken to the ISS by the Space Shuttle to deliver consumables, equipment, and tools. Oxygen brought up by the ATV is vented directly into the station, water is carried out in bags, and fuel is piped across to Zvezda. An ATV stays at the ISS for about six months. At intervals of 10 to 45 days, the ATV's thrusters are used to boost the station's altitude.
Over time, the station crew use the vehicle as a refuse skip, filling the cargo section with up to 6.4 metric tons of waste. After undocking, the ATV destroys all this material, and itself, in a controlled re-entry and burn-up over the Pacific Ocean.
The first ATV – dubbed "Jules Verne" – was launched atop a specially prepared Ariane 5 in March 2008. Four others are currently planned.
Future possibilitiesOn the design board now is a re-entry capsule that would be jettisoned by a returning ATV prior to the vehicle's destruction in the atmosphere. The capsule would land safely any experimental items from the ISS that were required for further study in Earth labs.
Another possibility is that ATVs could be given a more open architecture. This would overcome the approximately 80cm-width (30 inches) restriction placed on ATV packages by the size of the hatch. If the vehicle were made with no side walls, larger components such as batteries and gyros could be delivered to the station. Spacewalking astronauts could then maneuver these bulkier items into place with the help of the station's robotic arm. Although the ATV is not currently designed to carry astronauts the fact that it has a pressurized compartment inside which people can move around safely demonstrates that an ATV-based human transportation system could eventually be developed.
Related category• MANNED SPACEFLIGHT
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