PARIS — The International Space Station on Feb. 15 became more dependent than ever on Russia’s Progress cargo vessels when Europe’s fifth and last Automated Transfer Vehicle (ATV) undocked from the orbiting outpost.
The film here, created using photos taken by NASA astronaut Terry Virts, shows the ATV-5 slowly moving away from the space station before disappearing over the horizon.
The vehicle, which was filled with garbage after arriving with food, fuel and other supplies in August, was subsequently guided into an atmospheric re-entry over the South Pacific, where it burned up as planned.
ATV is by far the largest of the cargo vehicles serving the station and would have been capable, on its own, of pushing the 420,000-kilogram orbital complex into a lower orbit on a controlled descent into the same South Pacific re-entry corridor used by the ATV vehicles.
It remains unclear when the station will be retired. NASA wants to use it until 2024, and perhaps to 2028. Europe and Japan have yet to decide whether to continue operations beyond 2020.
Russia has sent mixed signals at a time when the war in eastern Ukraine has caused most dealings between Russian and the West – with the notable exception of commercial space launches and space station operations – to deteriorate.
However long the station continues to operate, its deorbit scenario now appears to depend on multiple Russian Progress supply vehicles.
The 21-nation European Space Agency (ESA) decided around 2010 to stop ATV production at five after debating whether to enhance the vehicle to allow it to return intact with experiments as Europe develops re-entry technology. Those plans never found sufficient financial support at ESA to proceed.
The reasons for ATV’s end after five flights were never clearly spelled out. ESA said that as a research agency it should not be in the business of building identical copies of the same hardware.
France, for its part, wanted to move on to a new multi-mission vehicle what would perform different tasks in low Earth orbit.
Europe had been using ATV missions – costing about 450 million euros ($585 million) each including launch aboard a European Ariane 5 rocket – to cover Europe’s 8.2 percent share of the space station’s common operating costs.
ESA and NASA have more recently agreed that ESA will provide the service module for NASA’s Orion crew exploration vehicle, with the current arrangement covering one complete module and parts for a second. What happens beyond that has not been decided.
NASA and ESA had been preparing the last ATV for a shallow atmospheric re-entry to mimic a space station module. That idea was scrapped when one of the ATV’s four batteries failed – a short circuit was suspected – in the days preceding the undocking.
While not a problem in and of itself, the battery failure added risk to the shallow re-entry plan because NASA had wanted the maneuver to occur around Feb. 27 when lighting and other conditions would yield maximum information about the vehicle’s descent through the atmosphere.
Because of the imminent arrival of a Progress vehicle at the same Russian docking port used by ATV, the vehicle would have been forced to remain in a holding pattern, detached from the station, for two weeks before the Feb. 27 re-entry. That was considered too risky given the battery failure.