In anticipation of the vessel’s upcoming launch, scheduled for 15 February, ATV Johannes Kepler is now being ‘tanked up’ with fuel at Europe’s Spaceport in Kourou.
Of all the vessels that can deliver cargo to the ISS, ATV can deliver the largest quantity of fuel, up to 5.5 tonnes maximum.
With this fuel, ATV can regularly reboost the Station’s orbit, which suffers a natural decay of 50 to 100 m each day (what goes up must come down – unless reboosted by ATV – Ed.) due to drag caused by traces of atmosphere at the ISS orbital altitude (roughly, 400km) .
The predecessor of Johannes Kepler, ATV-1 Jules Verne, conducted four reboots during its 5-month attached phase in 2008. All ATVs can also perform debris avoidance manoeuvres for the ISS.
Kepler also saves a portion of its fuel so that it can properly and safely perform its own de-orbit manoeuvre at the end of its mission, after undocking from the ISS .