| |  | | | Jules Verne ATV attached to the ISS |
ATV cargo capacity
Based on the current Ariane 5 launcher performance, the ATV can carry to the ISS slightly more than 6.6 tonnes of wet and dry cargo. In addition, for a typical mission profile (such as for the ATV-2 Johannes Kepler) ATV carries about 2.5 tonnes of fuel for its own use, i.e. for rendezvous and docking with the ISS, performing different manoeuvres on the way, and eventually deorbiting itself on conclusion of its mission.
The weights are calculated for each mission depending on the cargo need, but in general the total ATV net cargo capacity can be allocated as follows (of course not all the maximum quantities presented here can be carried at once on the same flight):
Wet cargo
Propulsive support propellant (up to 4.0 tonnes)
This takes up by far the largest proportion of the ATV cargo. This propellant is used by the ATV to reboost the ISS to a higher orbiting altitude in order to counter the effects of atmospheric drag, which cause the ISS to very slowly lose altitude, for ISS attitude control, and for ISS Debris Avoidance manoeuvres, whenever needed. The propellant consists of two different fluids: monomethylhydrazine (MMH) and mixed oxides of nitrogen (MON3).
Refuelling propellant (up to 860 kg)
Once attached to the Station, up to 860 kg of refuelling propellant can be transferred from the ATV to the ISS. This consists of two different fluids: the fuel unsymmetrical dimethylhydrazine (UDMH) and the oxidiser, nitrogen tetroxide (N2O4), which provides a source of oxygen so the fuel can ignite and burn in orbit. This is used by the ISS for orbit and attitude control with its own engines.
Water (up to 855 kg)
This is what is known as potable water for use by the crew for drinking, food rehydration and oral hygiene.
Gases (up to 102 kg)
Two out of three types of gases (oxygen, nitrogen and air) can be transported in order to resupply the atmosphere inside the ISS, which is similar to that on Earth.
Dry cargo
Up to 3.2 tonnes of dry cargo can be transported to the ISS inside the Integrated Cargo Carrier of the ATV. This may include food for the crew, spare parts, clothing, and a number of additional items.
ATV-2 Johannes Kepler
The next ATV to be launched, Johannes Kepler will have a maximum launch mass of 20 050 kg. The total net cargo (fluid and dry) load to be transported to the ISS will be about 6.6 tonnes. The spacecraft itself will have a 'dry mass' of about 9800 kg.
Last update: 9 March 2010 | |
