MOSCOW. Nov 23 (Interfax-AVN) - The scheme for the docking of Progress-M51 to be launched December 23 is likely to be changed, thinks Alexander Kireyev, head of the ballistic coordination team of the Russian Mission Control Center.
"Usually, the two-day scheme is used. But it is most likely that the three-day scheme will be chosen this time. It means that the approach and docking will be made at the 48th or 49th pass, rather than at the 33rd or 34th ones," he said.
In this case more work is in store for duty teams of the Mission Control Center and the ISS crew.
Kireyev added that these measures are necessary to remedy the failure to achieve the required altitude during the November 17 maneuvers, when the ISS orbit was lifted 2.7 km up instead of the 4.4 km planned. The orbit was corrected to ensure optimal conditions for Progress docking.
A commission of Mission Control Center and Energiya Company experts is investigating the incident.
According to Kireyev, it is unlikely that the engines of the Progress-M50 spacecraft might be employed to lift the station up once again even if the commission finds the exact reasons of the failure occurred November 17.
"All work at the ISS is scheduled tightly till December 2. There will be no time for any additional operations. After December 3, the station will occupy a position that will be very inconvenient for correcting the orbit. Additional fuel will have to be burnt to put the station right in convenient position, but the fuel stores in orbit are limited," he said.
According to him, the Mission Control Center plans to leave a fuel load at Progress-M50 that will allow it to be undocked and sunk. "The undocking and sinking of the spacecraft is a very complicated mission, so, it is better to have reserves," he said.
He added that it is unlikely that the launch from Baikonur will be delayed, as the time from December 22 to December 24 is the most effective in terms of ballistics.
According to Kireyev, the Mission Control Center leadership will make the decision before the weekend.
The Progress-M51 spacecraft will bring almost 3 tons of cargoes to the ISS, including fuel, oxygen, water, food. The ISS rooms an international crew of Salizhan Sharipov, Russia, and Leroy Chiao, the USA.