Albert Einstein, ESA’s unmanned cargo ferry at the International Space Station, will start pumping propellants today into the orbital outpost. This will be followed by air and oxygen transfers before it resumes boosting the Station’s orbit.
ATV-4 is the fourth Automated Transfer Vehicle to serve the Station; it was launched on 5 June and reached the complex nine days later. Since then, this European cargo carrier has been firmly attached to the Station, acting as an additional module.
All 2489 kg of dry cargo has now been carried into the Station and the crew has already loaded 1213 kg of waste into ATV. Around two more tonnes of unused equipment, rubbish and other material will be packed into the vehicle before it completes its mission in spectacular fashion as a cosmic rubbish removal van in late October, burning up safely as it reenters the atmosphere.
So far, ATV’s mission has been quiet, as everything goes according to plan. “We like having this kind of mission,” says Jean-Michel Bois, Head of the ESA Operations Team at the ATV Control Centre in Toulouse, France.
“Of course, there have been small issues – there always are – but they keep us on our toes. Everything is in a great state and ATV is working beautifully.”
The 60-strong team from ESA, France’s CNES space agency and industry at the control centre constantly monitor ATV’s health and they are always ready for unscheduled actions, like avoiding orbital debris by changing the Station’s orbit with ATV’s powerful engines. Albert Einstein has already preformed a major planned reboost, using 200 kg of propellant and raising the Station’s orbit by about 10 km.
The only significant unplanned event came last week, when one of ATV’s three computers was automatically shut down by onboard software. Then a second computer failed on Sunday – not a problem as ATV can operate fine with just one unit.
Even so, critical activities require all computers to be working normally so some of the Toulouse centre’s key personnel cut their holidays short to tackle the problem.
With this additional help, the two computers were soon restarted. ATV was then ready to go ahead with preparations for the propellant transfer.
Refuelling and refreshing the Station
The fuel pipes were pressurised on 31 July, leaving ATV ready to pump 860 kg of fuel and oxidiser into the tanks of Zarya module on Thursday afternoon. All of the available propellants will be transferred during the 1.5-hour operation, after which the pipes will be purged and evacuated to avoid any problems when ATV undocks.
Then air and oxygen will flow into the Station on 12 and 13 August. ATV-4 holds 66.3 kg of air and 33.3 kg of pure oxygen for the crew. It also arrived with 564 kg of water in its tanks, 23% of which has already been pumped into the Station’s tanks.
On 14 August, ATV will light up its engines for another orbit reboost, followed by another on 28 August.
According to planning, ATV will undock and head for the fiery end to its mission on 28 October.