* Astronomy

Deorbit burn in progress.

Commander Bill McArthur, Russian Valery Tokarev and Brazilian Marcos Pontes are due to undock their Soyuz capsule from the International Space Station today, and land in the Kazakhstan desert at 23:48 GMT (4:00 a.m. Moscow time. Just before dawn on Sunday in Kazakhstan).

Marcos Pontes arrived at the station about a week ago with the new expedition 13 crew. He is the first person from Brazil to fly into space.
Taking over the ISS for the next six months are Russian Commander Pavel Vinogradov and American Jeff Williams. They hope to get a third resident, German Thomas Reiter, with the shuttle crew slated to fly in July.
If that mission goes well, construction of the station could resume with the shuttle flight planned for late August.

The Expedition 12 crew and Brazilian astronaut who will land today are expected to undock at 20:25 GMT. The engine burn to take them out of orbit occurs around 23:00 GMT, with a landing at 23:48 GMT on the Kazakhstan steppes in darkness.

Russian helicopters, some carrying NASA personnel, will be on hand to meet the crew and provide initial aid and medical assistance if necessary. Eventually, they will be transported to Star City, the training centre north of Moscow.


After re-entering the Earth's atmosphere, the men will crash down somewhere near the Kazakh town of Arkalyk inside a metal capsule that detaches from the rocket, its speed is slowed with the help of parachutes.

The temperature at the landing site is likely to be as low as minus 12 degrees Celsius (10 degrees Fahrenheit)

Undocking: 20:45 GMT
Separation burn: 20:31 GMT
De-orbit burn: 22:57-23:01 GMT
Modules separate: 23:21 GMT
Atmospheric entry: 23:24 GMT
Command to open parachute: 23:33 GMT
Landing: 23:48 GMT

-- Edited by Blobrana at 19:58, 2006-04-08

Expedition 12 astronaut William McArthur and Russian cosmonaut Valery Tokarev have started their spacewalk out of the International Space Station after an hour-long delay.

Valery Tokarev, who is making a spacewalk for the first time, could not immediately locate the emergency pressure equalization valve inside the Quest lock chamber, meaning the chamber had to be resealed.

This marks the first time in two and a half years that astronauts have made a spacewalk wearing American EMU space suits.

The astronauts will carry out and launch an FPP probe, designed to monitor any build-up of static electricity at the station, and replace a rack for video cameras on the outer surface of the NODE module.

One of the crew's major chores on this spacewalk will be to climb to the top of the space station and unbolt a device called the Floating Potential Probe. This has measured the electrical charge outside the station, but it has since stopped working and some of its parts are loosening. As ships dock to the station they jostle it slightly, and NASA wants to make sure that parts of the probe do not shake free and damage other components outside the station.

The crew will toss the device overboard, towards Earth – it should burn up in the atmosphere within 100 days.
The other major task will be to affix a camera and tripod to the station's hull. The new camera will be used when the shuttle brings up new station parts, including solar arrays. The camera's perspective will aid the crew as they try to attach these massive pieces of hardware using the station's robotic arm.

If there is still time after finishing the camera and probe work, McArthur and Tokarev will replace a circuit breaker and a motor that rotates a radiator.

After a series of leak checks, to ensure an airtight seal between the ISS and Soyuz TMA-7 spacecraft, the hatches between the two spacecraft were opened at 0830 GMT.