July 14, 2009

ESA Nearing Completion Of Second Space Truck Model

The European Space Agency's (ESA) next space freighter is slowly being assembled for a November 2010 launch, BBC News reported.

Nico Dettmann, who is in charge of producing the follow-up ship to the current Automated Transfer Vehicle (ATV) - dubbed Johannes Kepler, knows the near-flawless maiden voyage of the last model does not mean the second flight is guaranteed to turn out the same way.

"It's clear from space history that often it was not the prototype that experienced the problems; it was the mission that came later. That's why specific attention has to be paid to what we do now," he said.

Therefore, attention to detail is everything.

The ATV's various segments, such as its propulsion and avionics units and its pressurized module, are currently being built in different parts of the world, but they will soon come together into a single line of assembly that will lead to a November 2010 launch date.

After that the ATVs will fly every year for three years.

"The whole integration process, from the first day until launch, is 28 months. So if you want to launch every 12 months, obviously you have to produce in parallel," explained Dettmann.

The development of the space freighter has huge significance for Europe's program, as it is the "subscription" Europe must pay to be part of the International Space Station "club".

If Europe can deliver about six tons of supplies a year to the platform, it is guaranteed six-month residencies on the ISS for its astronauts.

The ESA's ATV is the biggest, most sophisticated vehicle the bloc has ever flown in space. It's automatic rendezvous and docking technology allows it to find its own way to the station and attach itself without any human intervention.

The vehicle's capabilities will feed into many other exploration activities, at the Moon, Mars and other Solar System destinations, according to the space agency.

The agency may even upgrade the robotic truck so that it can carry people using an independent European crew transportation system.

After simplifying routine production, Astrium Bremen is now in sole charge of manufacturing Johannes Kepler.

Astrium's ATV project manager, Olivier de la Bourdonnaye said they used to have one organization dedicated to development and one to production, but at the end of Jules Verne, it was decided to have just one organization in order to have maximum consistency going forward.

About 50 percent of the production effort and all the sub-contractors"”including Europe's other major space concern, Thales Alenia Space"”are reporting direct to the German production center.

But the original Jules Verne ATV was so successful, that very little has to be changed on ATV-2, as there were only two significant hardware issues.

The first was the vehicle's propulsion system that switched to a back-up chain when anomalous pressures were detected in the complex network of pipes and valves that feed the engines.

The second was a segment of thermal blanket on the exterior of the craft that moved away from its Velcro fittings.

However, neither problem affected the mission and both were easily remedied on Johannes Kepler.

But there was also a slight mismatch that occurred in the advanced GPS systems used on ATV and the Russian Zvezda module on the ISS to align the vehicles prior to docking.

Concerns were raised that Jules Verne could have been triggered into aborting its approach to the platform had the discrepancy been more serious.

Fortunately, a software correction on the Russian side should fix this issue before Johannes Kepler arrives in 2010.

Also, at 20 tons, the vehicles launch will make it the heaviest payload in the history of ESA missions.

ATV-2 will play a significant role in boosting the ISS. With no shuttle visiting the station, only the ATV will have the power to lift the platform higher into the sky to avoid the drag from residual air molecules at the top of the atmosphere.

Dettmann said they're supposed to lift the station significantly because after the shuttle retirement the ISS will raise its average altitude to produce less drag.

He said as of now the ISS altitude is linked to low shuttle performance.

"After shuttle is gone, ISS can fly higher but ATV will have to deliver a major part of that altitude increase," he said.


Image Caption: Backdropped by the blackness of space, the Jules Verne Automated Transfer Vehicle (ATV) approaches the International Space Station on Monday, March 31, 2008, for its "Demo Day 2" practice maneuvers.


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