Russian Analysis of Failed ISS Reboost Nears Completion

Engineers work to integrate the Progress 19 supply ship into its Soyuz launch vehicle in preparations for its Sept. 8, 2005 launch toward the International Space Station (ISS). CREDIT: RSC Energia.

KOROLYOV, Moscow Region (Interfax) - The Mission Control Center in Korolyov near Moscow has almost completed its analysis of the sudden halt in the firing of the Progress M-54's engines during correction of the International Space Station's orbit, Energia corporation Vice President and Russian commander of the ISS flight Vladimir Solovyov told Interfax on Monday.

"Our experts have generally understood the reasons for the situation. We think it was an unstable indicator in one of the eight Progress engines," he said.

It was planned to correct the ISS's orbit with the help of Progress's engines on October 19. The engines were due to fire for 700 seconds, but they automatically shut down 77 seconds after they were switched on. The ISS's orbit was raised by 100-150 meters, instead of the planned 10 kilometers.

A test correction of the station's orbit is scheduled for October 26 to confirm the experts' theory, Solovyov said. "We will briefly turn on the engines for raising the ISS by approximately one meter per second and see how it goes," he said.

If the experts' theory is right, another orbit correction will be considered, he said. "We can do that on November 9, 16 or later," he added.

The ISS orbit will have to be raised for the December docking with the Progress freighter, which will be launched from Baikonur on December 21.

The ISS is orbiting at a safe altitude, Solovyov said. "The Sun is passing through a period of minor activity, and the orbit daily drops by approximately 50 meters. The current height of orbit is about 350 kilometers, so the orbit will remain safe without correction for 1.5 years," he said.

Russia does not want to lift the ISS orbit to 390-400 kilometers, which would require no further corrections, Solovyov said. "The thing is that 340-350 kilometers is best for docking with U.S. Space Shuttles. We are thus meeting the interests of our American partners," he said.

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