By Anatoly Zak
Phobos-Grunt and Yinghuo 1 are due for launch together
Less than two months before the scheduled launch of Russia's flagship planetary spacecraft, officials are set to recommend a delay until 2011.
The Phobos-Grunt mission aims to land on the Martian moon Phobos to collect soil samples and return them to Earth.
Sources within the Russian space industry gave RussianSpaceWeb.com details of the likely postponement.
The Russian space agency Roskosmos is expected to announce the mission's fate within a week.
The agency's decision will be based on results of testing which the spacecraft has been undergoing since July at its assembly facility at NPO Lavochkin in Khimki, near Moscow.
A delay for Phobos-Grunt would also affect China's first Mars probe Yinghuo 1, as the two craft are due to be launched together on the same Zenit rocket.
According to its latest increasingly tight schedule, the Phobos-Grunt spacecraft had to be shipped to the launch site in Baikonur Cosmodrome on 26 September 2009 in order to catch a narrow astronomical launch window to Mars in October of this year.
A previously announced timeline called for the shipment of the spacecraft to Baikonur in August, only to be pushed back to the middle of September 2009.
The decision to roll out the vehicle to Baikonur would mean a commitment to launch this year, while failure to do so would postpone the mission to 2011.
Industry sources said that despite all efforts, the probe's flight control systems are likely to need more tests before they can be considered reliable enough to survive a complex multi-year mission.
The systems will need to be robust enough to cope with complex manoeuvring in Martian orbit, landing on the surface of Phobos, the takeoff of the return vehicle and the landing of the capsule containing the soil samples on Earth.
A further argument to postpone the mission to 2011 would be lack of duplicate failsafe systems at Russian mission control to guide the spacecraft into deep space.
Currently Russia's only operational deep space antenna capable of sending flight control commands to Phobos-Grunt is in Ussuriyisk near Vladivostok. Any serious problems there would doom the mission.
A second antenna, in Medvezhi Ozera, near St Petersburg, could be capable of controlling the mission - but only after an upgrade, which is not expected to be completed until sometime next year.
Launching the spacecraft with only a single operational flight control antenna would endanger the mission, experts said.
Roskosmos recently reached an agreement with the European Space Agency, Esa, to use its facilities in the Phobos-Grunt project. But European ground control stations would only be capable of receiving data rather than controlling the spacecraft.
Those in favour of postponing the mission to 2011 argue that Russian scientists have not conducted a deep space mission for more than two decades, and available time to prepare the launch in 2009 was inadequate.
In 1988, a pair of Soviet probes was sent to Mars but one failed on its way to the red planet and the other soon after entering orbit. Flight control error was blamed for at least one failure.
Russia's latest probe to Mars, launched in 1996, crashed back to Earth when the launch vehicle failed. Lack of Russian ground control facilities meant the exact cause was never pinpointed.
Despite many previous unofficial reports that the beleaguered project would have to be delayed to at least 2011, the Russian space agency and NPO Lavochkin, the probe's primary developer, have always insisted that the mission would launch in 2009.
According to latest reports, the launch of Phobos-Grunt was pushed to the beginning of November 2009, essentially beyond the available launch window to Mars.
It was unclear how such a move would affect the mission, since launching outside of the astronomical window would limit the mass of the payload to be carried to Mars.
Delaying Phobos-Grunt from 2009 to 2011 might also have a knock-on effect on future Russian missions into deep space.
Experts say Phobos-Grunt is relatively well prepared for flight, so it would need little extra money to be ready for 2011.
However the same personnel and facilities employed in the preparation of the Phobos-Grunt project, at NPO Lavochkin and the IKI space research institute in Moscow, will be needed to design subsequent missions such as the Luna-Glob probe, which - according to the official schedule - is due to enter orbit around the Moon in 2011.