Weapon caused spacecraft’s failure?

MOSCOW — A Russian scientific spacecraft whizzing out of control around the Earth, and expected to re-enter the atmosphere on Saturday, may have failed because it was struck by some type of anti-satellite weapon, the director of Russia’s space agency said in an interview published Tuesday.

He did not say who would want to interfere with the spacecraft, which was intended to explore a moon of Mars.

The Russian craft, named Phobos-Grunt for the moon and the Russian word for ground, ran into trouble soon after it was launched in November, when its rockets failed to lift it out of low Earth orbit. What was to have been a two-and-a-half-year interplanetary journey to retrieve a soil sample from Phobos will instead end over the weekend, according to Russian engineers.

When the 13-ton Phobos-Grunt breaks up in the atmosphere, debris could potentially fall anywhere along a vast stretch of the Earth’s surface that includes the cities of New York, London and Tokyo. Though the odds are heavily against the debris causing any harm, the spectacle of people around the world anticipating the crash is another embarrassment for Roscosmos, the Russian space agency, which has presided over a series of rocket and satellite failures this year.

A statement from the U.S. Strategic Command acknowledged that it was tracking the space probe and that it is likely to fall in the next week. “Predictions of re-entry date, time and location can change significantly due to many changing factors, such as solar weather and orientation of the spacecraft,” the statement said. “These predictions become more accurate as the event approaches.”

When Phobos-Grunt first went awry, the director of the Russian space agency, Vladimir Popovkin, said that a flawed navigational computer might be to blame.

NASA officials said that they helped Roscosmos, using NASA’s antennas known as the Deep Space Network, to try to re-establish contact with Phobos-Grunt, and that NASA had continued these efforts until the antennas were needed for the launch of its Mars Science Laboratory spacecraft on Nov. 26.

Popovkin’s remarks to the newspaper Izvestia were the first high-level suggestion of nefarious interference. A retired commander of Russia’s missile warning system had speculated in November that strong radar signals from installations in Alaska might have damaged the spacecraft.