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ESA PR 15-2008. Jules Verne, the first of the European Space Agency’s Automated Transfer Vehicles (ATV), a new series of autonomous spaceships designed to re-supply and re-boost the International Space Station (ISS), was successfully launched into low Earth orbit by an Ariane 5 vehicle this morning. During the coming weeks, it will manoeuvre in order to rendezvous and eventually dock with the ISS to deliver cargo, propellant, water and oxygen to the orbital outpost. Lift-off occurred at 05:03 CET (01:03 local) from the Guiana Space Centre, Europe’s spaceport in Kourou, French Guiana. This flight required a new version of Europe’s workhorse launcher, the Ariane 5ES, specially adapted to the task of lofting the nearly 20-tonne vehicle – more than twice as heavy as the previous largest Ariane 5 payload – to a low circular orbit inclined at 51.6 degrees relative to the Equator and equipped with an upper stage with re-ignition capabilities. The unusual launch trajectory required the deployment of two new telemetry tracking stations, one on a ship in the Atlantic Ocean and one on the Azores Islands. The Ariane 5 upper stage performed an initial 8-minute burn over the Atlantic and entered a 45-minute coast phase, flying over Europe and Asia before reigniting for a 40-second circularisation burn over Australia. Separation of Jules Verne ATV occurred at 06:09 CET (02:09 local) and was monitored by a ground station located in New Zealand.
Jules Verne ATV is now circling the Earth in the same orbital plane as the ISS but at an altitude of only 260 km, compared to 345 km for the Station. The vehicle is under constant monitoring by the dedicated ATV Control Centre in Toulouse, France. Located within the premises of the French Space Agency CNES, the ATV Control Centre will ensure flight control throughout the mission in coordination with the ISS mission control centres in Moscow and Houston. After having demonstrated safety manoeuvres in free flight, the ATV will perform orbital ‘phasing’ manoeuvres in order to rendezvous with the ISS for a first docking slot scheduled for 3 April after the departure of NASA’s Space Shuttle Endeavour. Named after the famous French 19th century visionary and author, the Jules Verne ATV is the largest and most sophisticated spacecraft ever developed in Europe, combining the functions of an autonomous free-flying platform, a manoeuvrable space vehicle and a space station module. About 10 m high with a diameter of 4.5 m, it weighed 19,357 kg at launch. It incorporates a 45-m3 pressurised module, derived from the Columbus pressure shell, and a Russian-built docking system, similar to those used on Soyuz manned ferries and on the Progress re-supply ship. About three times larger than its Russian counterpart, it can also deliver about three times more cargo. The ATV is also the very first spacecraft in the world designed to conduct automated docking in full compliance with the very tight safety constraints imposed by human spaceflight operations. It features high accuracy navigation systems and a flight software far more complex than that used on Ariane 5.
Decided by ESA in 1995 in order to pay for its contribution to the operational costs of the ISS, the ATV has been under development since 1998 by an industrial team led by Astrium Space Transportation and comprising more than 30 contractors from 10 European countries. On this first ATV mission, Jules Verne will deliver 4.6 tonnes of payload to the ISS, including 1 150 kg of dry cargo, 856 kg of propellant for the Russian Zvezda module, 270 kg of drinking water and 21 kg of oxygen. On future ATV missions, the payload capacity will be increased to 7.4 tonnes. About half of the payload onboard Jules Verne ATV is re-boost propellant, which will be used by its own propulsion system for periodic manoeuvres to increase the altitude of the ISS in order to compensate its natural decay caused by atmospheric drag. Upon leaving, after four months spent docked to the ISS, Jules Verne ATV will carry away waste from the Station. It will then be de-orbited over the Southern Pacific Ocean and burn up in the atmosphere in a fully controlled manner.
Beyond Jules Verne, ESA has already contracted industry to produce four more ATVs to be flown through to 2015. With both ESA’s ATV and Russia’s Progress, the ISS will be able to rely on two independent servicing systems to ensure its operations after the retirement of the US space shuttle in 2010. The Japanese HTV (H-II Transfer Vehicle) will also soon join the scene. This will be vital to ensure the system's overall robustness and reliability. “Last month, with the docking of Columbus, Europe got its own flat in the ISS building, with the launch of the first ATV, we now have our own delivery truck” said Daniel Sacotte, ESA’s Director for Human Spaceflight, Microgravity and Exploration. “We have become co-owners of the ISS, now we are about to become fully- fledged partners in running it. With the ATV we will be servicing the ISS by delivering cargo and providing orbital reboost.”
Mission concept and the role of ATV
The International Space Station (ISS) depends on regular deliveries of experiment equipment and spare parts, as well as food, air and water for its permanent crew. From 2008 onward, the Automated Transfer Vehicle (ATV) will be one of the indispensable ISS supply spaceships. It is developed under ESA contract by a European industrial consortium lead by EADS Space Transportation, in France. The ATV will remain attached as a pressurised and integral part of the Station for up to six months. After that it will start its final mission: a so-called destructive re-entry into the Earth's atmosphere during which it will break up and burn, together with up to 6.4 tonnes of material that is no longer used on the Station.
To succeed in docking safely with a huge manned station, ATV has to be a highly intelligent and powerful spacecraft. The exterior is a white coloured cylinder 10.3 metres long and up to 4.5 metres in diameter. The ATV structure is covered with an insulating foil layer on top of meteorite protection panels. Extending from the main body of the spacecraft are its characteristic x-shaped metallic blue solar arrays. Inside, the ATV consists of two modules, the Service Module and the pressurised Integrated Cargo Carrier. The forward part of the Cargo Carrier docks with the ISS. Although no crew will ever be launched in an ATV, once attached to the Station, astronauts dressed in regular clothing will enter inside to load and unload cargo. The Cargo Carrier is very much like the European-built Multi Purpose Logistics Module (MPLM), from which it is derived. The MPLM has already flown as a space barge transporting equipment to and from the Station using the Space Shuttle. The ATV, which is equipped with its own propulsion and navigation systems, is a multi-functional spacecraft, which combines both the full automatic capabilities of an unmanned vehicle, with human spacecraft safety requirements. ATV's mission in space will resemble the combination of a tug boat and a river barge.
The 48 m³ pressurised section has room for up to eight standard racks which are loaded with modular storage elements used for cargo. The Integrated Cargo Carrier also holds several tanks, containing up to 840 kg of drinking water, 860 kg of refuelling propellant for the Station's own propulsion system and 100 kg of air (oxygen and nitrogen). The 'nose' of the cargo section contains the Russian-made docking equipment with rendezvous sensors and antennas. The ATV's Service Module navigates with four main engines (490 N thrust) plus 28 smaller thrusters (220 N) for attitude control. After docking, the ATV can perform attitude control and debris avoidance manoeuvres for the whole Station.
At regular intervals the ATV also boosts the ISS into a higher orbit to overcome the effects of the drag of the remaining atomic oxygen molecules above the Earth's atmosphere. The Station's natural altitude loss can reach up to several hundreds of metres a day. To perform these manoeuvres the ATV uses up to 4.7 tonnes of propellant. From its first operational flight planned for 2008, Europe's most challenging spacecraft will play a vital role in Station servicing. It is also a way for Europe to pay its share in ISS running costs by spending money within the European industry rather than by cash transfers to its International Partners. Depending on the operational lifetime of the ISS, ESA plans to build five ATVs. Thirty companies from ten European countries, as well as eight other companies from Russia and the United States share the work, with EADS Space Transportation (France) as the Prime Contractor. |
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