ESA to study two-way transfer vehicle for International Space Station for service flights after Shuttle is retired
Europe is studying a development of its automated transfer vehicle (ATV) capable of returning cargo to Earth from the International Space Station (ISS) once the US Space Shuttle has been retired. A Phase B study of the proposed two-way cargo access and return vehicle (CARV) is under way, says Marco Caporicci, head of the European Space Agency's re-entry and human transportation division.
Weighing almost 21t at launch by Ariane 5, ESA's ATV is designed to carry 7.6t of cargo, air, water and fuel to the ISS, then to take on 6.5t of waste and burn up on re-entry. The CARV has a re-entry capsule in place of the ATV's cargo carrier, allowing a substantial payload to be returned to Earth, including ISS spares for refurbishment.
NASA, which issued a request for information on 16 July soliciting proposals for cargo and crew services to the ISS, plans to continue using Russian Progress cargo-resupply and Soyuz-TM crew-transfer vehicles, plus Europe's ATV and Japan's similar HTV cargo-transfer vehicle, after the Shuttle is retired. But, like Progress, neither the ATV nor the HTV has the capability to return cargo to Earth.
While the ATV is designed to use the Russian docking and refuelling system on the ISS, the CARV would be compatible with the station's wider-diameter US docking port, allowing larger items to be loaded and unloaded. Caporicci says a go-ahead decision is scheduled for 2006, with the CARV planned to be available by 2010, NASA's current date for retirement of the Shuttle upon completion of ISS assembly.
EADS Space, meanwhile, has begun construction of the second of seven planned ATVs under a new €1 billion ($1.24 billion) contract from ESA. Originally scheduled to fly in September 2003, the already-completed first ATV - Jules Verne - will now be launched in late 2005.
The delay is due to the hiatus in ISS assembly and problems with the ATV's autonomous docking software. "We need to test it fully [in simulations]. Although unmanned, [the ATV] has to match all the safety requirements of the manned Space Station," says EADS. The second ATV will be built before a production review in 2005 that should give the go-ahead for the remaining five vehicles. The six ATVs still to be built will cost €835 million.
The rest of EADS's €1 billion ESA contract is split between €180 million for work already performed on the European ISS laboratory module, Columbus, and €30 million to prepare for its eventual launch on a future Shuttle mission.
GRAHAM WARWICK / WASHINGTON DC
ADDITIONAL REPORTING BY ROB COPPINGER