Saturday, April 19, 2008

Expedition XVI Returns to Earth

Soyuz TMA-11 spacecraft shortly after undocking. Credit: NASA TV

Crew takes Soyuz on later, 'ballistic' re-entry, lands 400 km short
Dr. Whitson breaks American endurance record


Commander Peggy Whitson and cosmonaut Yuri Malenchenko of the 16th International Space Station crew landed on the steppes of Kazakhstan Saturday after 192 days in space.

All three people aboard the Soyuz TMA-11 spacecraft were reported to be in good condition after their re-entry and landing.

With Whitson and Malenchenko was spaceflight participant So-yeon Yi. She launched to the station April 8 with the Expedition 17 crew, Commander Sergei Volkov and Flight Engineer Oleg Kononenko, under contract with the Russian Federal Space Agency.

Astronaut Garrett Reisman came to the station aboard Endeavour on its STS-123 mission, launched March 11. He served for the last few weeks as a member of Expedition 16. He remains aboard as a member of the Expedition 17 crew.

Expedition 16 crew members undocked their Soyuz spacecraft from the station at 0506 UT. Saturday. The deorbit burn to slow the Soyuz and begin its descent toward the Earth took place at 0840.

When they landed, Whitson and Malenchenko had spent 192 days in space on their Expedition 16 flight, 190 of them on the station.

All three aboard the Soyuz TMA-11 were reported to be in good condition after a somewhat hairy re-entry and landing, however.

For the second time since October, Roscosmos announced the crew made a decision to take a steeper, slower, hotter and more dangerous "ballistic" re-entry path, without informing ground controllers.

Speculation has it an automatic re-entry burn sequence failed, requiring an immediate decision to trigger the re-entry burn manually, only a moment late but short of a degree of arc further along it's orbital path. A steeper angle would then have been required to land within the same target area, and the manual burn may have over compensated for the change in timing.

Compensating for a momentarily late burn, the crew re-entered Earth's atmosphere at perhaps 0.2 degrees wider an angle.

The crew arrived approximately 295 miles from the expected landing oval, delaying recovery forces’ arrival at the spacecraft's stopping place by approximately 45 minutes.

Whitson, 48, returned from her second mission to the station. She served as a flight engineer on the Expedition 5 crew, launching June 5, 2002, and returning to Earth Dec. 7 after almost 185 days in space.

She landed Saturday with a total of 377 days in space, more than any other U.S. spacefarer. On April 16 she broke the previous mark of 374 days set by Mike Foale on his six flights.

She holds a Ph.D. in biochemistry from Rice University in Houston. She began working for NASA as a research biochemist in 1989 and was selected as an astronaut in 1996.

Malenchenko, 46, a Russian Air Force colonel, is making his third long-duration spaceflight. He spent 126 days aboard the Russian space station Mir beginning July 1, 1994, and commanded Expedition 7, spending 185 days in space beginning April 26, 2006. He also was a member of the STS-106 crew of Atlantis on an almost-12-day mission to the station beginning Sept. 8, 2000.

He landed Saturday with a total of 515 days in space on his four flights. He has the ninth highest total of cumulative time in space of all humans.