After four years of flawless performance shuttling cargo and fuel to the International Space Station (ISS), Europe's most sophisticated spacecraft appears destined to serve as a subsystem aboard 's next deep-space exploration demonstrator.
In late September the third of five Automated Transfer Vehicles (ATVs) was set to complete its six-month mission at the ISS, with an undocking from the orbiting outpost before burning up in Earth's atmosphere during a controlled, destructive reentry. Although two additional ATVs are slated to launch in 2013 and 2014, respectively, production of the vehicle—arguably one of Europe's most forward-looking and successful technological feats—has already ceased, with no clearly defined follow-on in the works.
Rather than evolve the Astrium-built spacecraft to conduct even more technologically challenging missions, for now the European Space Agency (ESA) is proposing to use ATV-derived technology in a propulsion module that will power's Orion Multipurpose Crew Exploration Vehicle (MPCV), an in-kind contribution valued at roughly €450 million ($580 million) that would cover Europe's share of ISS common operating costs through 2020.
The argument for bartering ATV technology in exchange for keeping the lights on in Europe's Columbus research module is, not surprisingly, cost: “The barter element was cheaper than the cost of ATV-6,” ESA Director General Jean-Jacques Dordain said during the Berlin air show last month, nine weeks ahead of a key meeting of ESA ministers who, in November, will set the agency's budget for the next several years.
“It is also a way to do development activities and maintain some industrial capability,” Dordain says of the Orion propulsion-module proposal.
Germany, as Europe's largest financial contributor to the ISS, appears content with the plan, so long as groundwork is laid for a future ATV-derived capability in November.
“In space we don't have to invent everything new every day, but we should use our heritage to make some progress in some special areas,” says Johann Dietrich Woerner, head of the German Aerospace Center (DLR). “To use the ATV as a basis for the development of a service module, which at the same time can be used for different goals, is a very good step forward.”
France—which has threatened to end participation in ISS beyond 2015 in order to pay for other priorities, including development of a next-generation launch vehicle—favors a more ambitious barter-element proposal. Dubbed the Versatile Autonomous Concept (VAC), the ATV-derived spacecraft could be capable of orbital debris collection and in-space servicing missions.
VAC cost estimates, however, range from €700 million to in excess of €1 billion, making the VAC unlikely to survive next month's budget talks.
“We have to please the participating states. And we have to please NASA,” Dordain says, though he stresses the barter element must do more than simply hand over existing technology to ESA's most valued partner. “It must be good for the future also, because it could not just be a dead end or a one-off which will have no future.”
Conceived and designed more than 15 years ago, ATV has features that make it unique compared with other resupply vehicles: The versatile cargo tug docks autonomously with the ISS and also provides extra crew quarters and engine power for the space station.
Woerner says despite the high cost of maturing ATV technology into something like the VAC, Germany would like to see it evolve into something more than a service module. Last month, DLR awarded Astrium a €15 million contract to conduct preparatory work for the center's Deutsche Orbitale Servicing (DEOS) project, a robotic spacecraft concept that would develop an operational in-orbit servicing system.
In addition to servicing missions, DEOS could be used to deorbit old satellites.
In the meantime, if ESA adopts the service-module proposal next month, its development could afford European industry an opportunity to keep skills sharp until a more advanced technology effort is funded, says Volker Schmid, head of ISS utilization at DLR.
“The integration and work with the U.S. in that respect is certainly a new thing, with all the testing which might be done through a cooperative approach,” he says. “From the technology standpoint, it is not quite a development like ATV was in the past—from the very beginning to a fully new vehicle—but it's a kind of adaptation, which has challenges and difficulties.”