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New state of the art software will safeguard ATV rendezvous   Cooperation between Europe and Russia on the integration of the Automated Transfer Vehicle (ATV) with the International Space Station lasted more than a decade and culminated with a flawless docking of the first European cargo craft to the station’s Zvezda Service Module on 3 April 2008. All Russian systems aboard the ATV (the Refueling System, Docking System, Equipment Control System, and KURS) demonstrated a stunning level of performance at all respective phases of the mission. All major joint tasks, such as delivery of dry cargo to the ISS, water transfer, re-pressurization with oxygen, ISS re-boost with ATV thrusters, attitude control, and a debris avoidance manoeuvre, were fulfilled without a hitch. The giant freighter destroyed itself in a controlled burn-up over the southern Pacific on 29 September 2009. It is currently planned to launch an ATV every 17 months as part of ESA's ISS membership agreement to haul cargo, propellant, water and oxygen to the space station, and also to provide propulsion capacity at the station. The ATV is 9.794m long, weighs 19.357 tonnes and has a total cargo capacity of 7.667 tonnes.  If Europe’s Automated Transfer Vehicle (ATV) encounters difficulties during rendezvous with the International Space Station (ISS), some highly sophisticated software will be on-hand to take over operations and avoid a potentially dangerous situation.
Upon detection of a critical failure or an unsafe situation, the Monitoring and Safing Unit (MSU) isolates the ATV’s nominal system and commands a Collision Avoidance Manoeuvre (CAM). This brings the ATV on a safe trajectory within the monitoring corridor towards the ISS. Once the Collision Avoidance Manoeuvre is completed, the MSU points the vehicle towards the Sun, thus ensuring sufficient power from the solar panels during the ‘survival’ mode that the vehicle enters.  The ATV's Monitoring and Safing Unit (MSU) (outlined in red) and the three electronic boxes (outlined in yellow) for the Fault Tolerant Computer (FTC) inside Jules Verne ATV avionics bay.
The triple FTC, which is the main computer, plays the role of a pilot that navigates the ATV. The Monitoring and Safing Unit (MSU) can be compared to a pilot responsible for safety, hidden inside the automated spaceship responsible for the mission.  ATV avionics bay  This is the Jules Verne ATV (in accelerated motion) during the final approach towards the ISS. It has to take place at a predefined closing velocity and within a predefined rendezvous safety corridor which consists of a virtual funnel (represented here) converging to the Station. Any abnormal behavior of the ATV would automatically lead to a Collision Avoidance Maneuver(CAM) which can also be manually commanded by the ATV Control Centre (ATV-CC) in Toulouse, France, or by the ISS crew in orbit. MSU : A small and robust last resort  The first ATV flight model, was tested at ESTEC in Noordwijk, the Netherlands. Here Jules Verne is being moved into the Maxwell electromagnetic radiation chamber. Software under scrutiny  In combination with ESA's new Ariane 5, 8.5 m-long Automated Transfer Vehicle (Verne) will enable Europe to transport cargo to the International Space Station. The 45 m³ pressurized module of the ATV delivers up to 7,2 tonnes of equipment, fuel, food, water and air for the crew. A fruitful collaboration  EADS ST (in Les Mureaux) and ESA MSU team Top, from left to right: Narmada, Michel Yu, Klaus Ludwig, Xavier Clerc, Olivier Boudillet, Marie-Odile Devic, Alain Robisson, Louis Fernandes
Bottom, from left to right: Bruno Cavrois, Maxime Senes, Nuno Silva, Eric Zekri, David Berthelier Release date: 30 June 2006 |