What are the key objectives of the ATV-2 mission?
What are the main differences between ATV-1 and ATV-2? Are they twins?
ATV-1 ‘Jules Verne’ and ATV-2 ‘Johannes Kepler’ are virtually identical in design. The Jules Verne mission was a huge success and the main challenge for the ATV-2 has been to move into the industrial production phase. The lessons learned from the first flight have allowed us to make a number of improvements to the ATV-2. These include more cargo-carrying capacity (+ 25%) thanks to new storage racks, more robust communications between the ATV and the ground, and a number of modifications to the flight software in response requests from the ATV Control Centre. The external heat shielding was modified to avoid the problems encountered on the first flight, as was the pressure regulator. However, the design of the ATV-2 remains very similar to that of the ATV-1.
Nevertheless, in terms of the mission, the sequence of operations will be significantly different. The first flight was a qualification flight, which included a number of demonstrations, in particular during the ISS approach phase. The Johannes Kepler will go straight to the station, considerably shortening the period spent in orbit prior to docking.
What are the key objectives of this second mission?
They are essentially logistical. The ATV-2 will play its freighter role in full, by supplying more than seven tonnes of cargo (as opposed to 4.6 tonnes in the ATV-1) plus fuel for station orbit re-boost manoeuvres.
Of the 7,090 kg of cargo carried, fuel accounts for 4,535 kg. During the period when it is docked with the ISS, the ATV-2 will conduct station re-boost operations to raise it from its current altitude of 360 km, an orbit it occupies to allow docking by the US Space Shuttle, to a higher orbit at 400 km. To do this, the ATV uses the fuel it carries itself and its own engines. Six re-boost operations are scheduled. This fuel can also be used for debris avoidance manoeuvres, which obviously cannot be planned in advance. But the ATV is extremely flexible and can react in real time.
Finally, at the end of the three and a half months, the ATV-2 will be filled with waste materials from the ISS, undock from the station and, just like the ATV-1, will burn up during re-entry through the upper layers of the atmosphere.
How is the integration of the ATV-3 progressing? What are the main industrial challenges with this model?
The three modules of the ATV-3, named Edoardo Amaldi after the famous Italian physicist, are today completed. It is beginning the final integration and testing phase at Airbus Defence and Space’s Bremen site and should be leaving for Kourou next August, for launch in early 2012. The main industrial challenge here is to continue to improve its performance and its operational flexibility for the ISS partners. Its internal layout in particular has been completely redesigned to further increase its cargo-carrying capacity.
The other major challenge will be to integrate the ATV-3 system and run the ATV-2 mission at the same time. This will demand a high degree of availability and responsiveness from Airbus Defence and Space’s engineering and AIT teams, in particular if they have to deal with any anomalies on the Johannes Kepler in orbit. However, all these teams, both in France or Germany, have already proven themselves and demonstrated their total commitment, and I know that they will rise splendidly to any challenge.
As prime contractor to the European Space Agency (ESA), Airbus Defence and Space is leader of an industrial team involving 30 main contractors from the 10 European countries participating in the ATV programme, together with Russia and the USA.
Seven tons of cargo
The ATV-2 ‘Johannes Kepler’ carries 7,090 kg of cargo (solids and fluids):
It should be noted that one of these experiments carried is Geoflow II, developed by Airbus Defence and Space for the European Space Agency (ESA). Geoflow II will help scientists to gain a clearer picture of fluctuations in the Earth’s mantle and a better understanding of the phenomena which lead to volcanic eruptions, tectonic plate movements and earthquakes.
Find out more! A special dossier full of informative articles and videos has been created about the ATV ‘Johannes Kepler’.