MOSCOW. Jan 17 (Interfax) - The optimal date for launching the Russian interplanetary station Phobos-Grunt to the Martian moon Phobos is November 11 2011, the six same digit day, leading researcher Natan Eismont of the Russian Academy of Sciences' Space Research Institute told Interfax-AVN.
"The astronomical window for the launch will open on October 31 and last until November 22, but November 11 is the optimal date," he said.
"If the spacecraft is readied by the end of October, it will be launched on November 11. But if problems arise the launch may be put off until November 22," he also said.
If still, the launch is cancelled, the window may be extended further, but if the delay is too long, the launch will be postponed until 2013, the research said.
The carrier rocket and the upper stage will fail to accelerate the Phobos-Grunt to a required speed if the spacecraft is launched a little earlier or a little later than the astronomical window allows. The speed could otherwise be accelerated, if the payload is cut and part of important research equipment is removed, which no one will welcome, he said.
The astronomical window to appear in 2011 is a little worse than in 2009, when it was particularly good for an Earth-to-Mars mission. The position of planets is favorable for the mission once in 11-12 years.
The interplanetary station Phobos-Grunt is intended to deliver soil samples from Phobos to Earth, and to study Phobos, Mars and the space around them. After reaching a Martian orbit the station will depart from the Chinese satellite Inghuo-1, land on Phobos, take soil samples and go back to Earth. The mission is to last three years.