The European Space Agency (ESA) Jules Verne Automated Transfer Vehicle (ATV) spaceship should be ready to support International Space Station supply missions in 2007, according to ATV Project Manager John Ellwood.
Despite problems with integration issues, the vehicle is 98 percent complete. The ATV is the most complex spaceship ever developed by Europe.
Tested and assembled at ESA’s research and technology centre, ESTEC, in Noordwijk, Holland, the 20 ton ship has been under the spotlight of ESA engineers since 2004. Despite their best efforts, the ATV is expected to make its debut two years late. Full flight simulations are set for 2006.
‘Obviously we cannot launch unless we have everything 100 percent ready and fully tested’, said John Ellwood, ESAâ€™s ATV Project Manager in an ESA press release today. ‘The extensive three-year test campaign on such a complicated programme – with its unavoidable problems and delays – will push us back by almost one year, to 2007.’
ESA suffered a major setback in April, when a small structural failure was deemed as too far reaching in risk management – thus requiring a major re-work and replacement of the ATV’s 48 valve-actuators in the Jules Verneâ€™s fuel pipeworks of the propulsion system, buried deep in the then-completed ATV. This caused a delay of nearly half a year in the processing of the vehicle.
Another failure was spotted on the drive mechanism of the crucial solar arrays – forcing a back-up device to be installed.
‘The bad luck is that these two failures occurred on some critical hardware late in our test campaign,’ added John Ellwood. ‘We now need to have them fully refurbished and put back in flight configuration before the start of the environment testing, such as the main acoustic tests now set for February next year.
‘The discovery of the problems can also be viewed in a positive light since we are able to fix them now. If they had been discovered later, they could have been mission-threatening at launch.’
The Russians – a major partner in the ATV project – also impacted on the schedule, with new requirements and specifications which forced a level of reprogramming of the ATV’s flight software.
â€œOf course, when something changes on board the ISS, we do not have any other choice than to adapt,’ added Nicolas Chamussy, EADS-ST ATV Programme Manager.
‘For example, when the Russians inform us that, in a couple of months, the GPS receivers on the Station – that Jules Verne will be using for rendezvous navigation – have been changed or when NASA tells us that the ATV has now to be able to undock regardless of the attitude of the Station, we have to make new calculations and new tests each time to be sure that we are compatible; sometimes these changes are for the better, but they come late in our schedule and they still take timeâ€, said
However, all the requirements of the ATV have now been set, allowing ESA engineers to complete their integration of the software into the vehicle.
‘To develop the incremental software versions is an on-going technical challenge, which presented some problems over the last years. We have made a lot of progress and the software is now stable. So we are confident that we – along with EADS – are going to meet the new date,’ added Ellwood.
‘Whenever, you are pushing the technical barriers, you are bound to meet some obstacles along the way. Therefore, the problems we are encountering with Jules Verne are not exceptional, except that this programme is more complex than anything else we have tried to do in Europe.
‘However we are also making great progress in most areas of this fascinating endeavour.’