Dainty space truck proves itself

By Jonathan Amos
Science reporter, BBC News

All the ship's systems appeared to work perfectly

Europe's "Jules Verne" freighter has demonstrated its ability to make extremely fine movements right next to the International Space Station (ISS).

The 20-tonne cargo ship edged up to within 12m of the back of the platform and then moved away to a safe distance.

The dress rehearsal was demanded by the station partners to prove the truck has the necessary control to make an automatic docking on Thursday.

Jules Verne is carrying food, water, air, fuel and equipment for the ISS.

The unmanned vehicle is the biggest, most sophisticated spacecraft yet flown by the European Space Agency (Esa).

The freighter, and the identical logistics ships that will follow in the years ahead, will be the way Europe pays its way on the space station project.

See where Jules Verne is right now

Monday's demonstration day appeared to go flawlessly. The three mission control centres overseeing operations - in France, Russia and the US - reported no immediate problems.

Jules Verne, which has the generic name of Automated Transfer Vehicle (ATV), began its practice manoeuvres from a distance of 39km.

It progressed though a series of "holding points" at 15.5km, 3.5km, 250m, and 20m from the back of the platform's Russian Zvezda module. At each waypoint, the space truck was given permission to take the next thrust forward.

Shortly after 1630 GMT, it was sitting just 12m from Zvezda and perfectly aligned with the docking mechanism. It was an impressive piece of formation flying - both space station and Jules Verne moving across the surface of the Earth at some 27,000km/h.

Yuri Malenchenko, the Russian cosmonaut on the platform, then sent a command to the ATV to remove itself from the vicinity of the ISS; the truck eventually taking itself 39km from the station.

Cost: Total bill was 1.3bn euros (at least 4 more ATVs will be built)

Total cargo capacity: 7.6 tonnes, but first mission is flying lighter

Mass at launch: About 20 tonnes depending on cargo manifest

Dimensions: 10.3m long and 4.5m wide - the size of a large bus

Solar panels: Once unfolded, the solar wings span 22.3m

Engine power: 4x 490-Newton thrusters; and 28x 220N thrusters

Mission Guide: Jules Verne

Monday's manoeuvres were essential because they gave a trial run to the technologies that are used to guide the Jules Verne onto its docking port.

The main system is a pair of videometers. These analyse the behaviour of laser light reflected off Zvezda to compute the vehicle's orientation and distance from the platform.

They are backed up by a pair telegoniometers, which work in a similar way to radar and continuously calculate the distance and direction from the ATV to the ISS.

Both systems are switched on from the 250m waypoint.

Jules Verne has now completed all its commissioning tasks.

Space station managers will meet on 2 April to assess events but it looks likely to be a very short gathering, ending with formal approval for a Thursday docking which has already been given a preliminary time of 1441 GMT.

Once docked, the air inside the ATV's pressurised section will be "scrubbed" clean. ISS Commander Peggy Whitson and her crew are expected to be allowed to move around freely inside their new "store room" from Friday.

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FOLLOW THE PATH OF THE ISS OR ATV Credit: Ciprian Sufitchi (N2YO.com)

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