WASHINGTON ? The Russian space agency, Roskosmos, has decided to postpone the launch of a mission to the Martian moon Phobos from 2009 to 2011, according to a U.S. scientist involved in the first Russian-led interplanetary mission in more than a decade.

The Phobos-Grunt mission had been slated to lift off aboard a Zenit rocket in October on a three-year mission to study Phobos and return rock and soil samples to Earth. The rocket also was to carry a Mars orbiter contributed by China.

Bruce Betts, director of projects at the Pasadena, Calif.-based Planetary Society, says Roskosmos officials decided Sept. 21 to postpone the Phobos-Grunt mission until the next favorable launch window opens in late 2011.

?In recent months, the Phobos-Grunt mission team has been making every effort to meet the October 2009 launch period,? Betts wrote in a Sept. 21 update posted on the Planetary Society?s Web site. ?More recently, the fully integrated spacecraft has been undergoing testing at NPO Lavochkin, the industrial organization where the spacecraft is being built. It appears that those tests could not be completed in time to assure the spacecraft?s readiness for launch.?

The Phobos-Grunt mission consists of an unmanned lander and sample-return craft. The Planetary Society contributed a tiny payload known as the Living Interplanetary Flight Experiment that was delivered to Russia this summer for integration with the spacecraft.

China?s Yinghou-1 Mars orbiter was slated to launch along with Phobos-Grunt aboard the same Zenit rocket.

Russia?s last interplanetary mission was Mars 96, an orbiter and lander mission that was lost in a November 1996 launch failure.

  • Phobos Up Close
  • The Best Martian Landings of All Time
  • Image Gallery: 20 Great Rocket Launches