Vladimir Popovkin, head of Russia's federal space agency Roscosmos, said heavy charged particles in space might have affected the suspect chips, causing two parts of the on-board computer system of the Phobos-Grunt spacecraft to unexpectedly reboot, ITAR-Tass reported Tuesday.
This rebooting caused the spacecraft to switch to a low-power, energy-saving mode with a subsequent failure of the craft's engines to fire and send it on its way to Mars, he said.
Popovkin said he was not ruling out the possibility the chips failed because they were, in fact, counterfeit.
The chips were less expensive than those used in earlier spacecraft because they were imported, he said.
That led to suspicions of counterfeit chips, he said, noting both NASA and the U.S. Defense Department have conducted investigations over counterfeiting of such products.