The commission's investigation found no faults with the spacecraft's hardware, a summary of its report released on the Web site of the Federal Space Agency Roscosmos said.
The $165 million Phobos-Grunt spacecraft was to travel to the Martian moon Phobos and bring back samples of its soil by 2014 but got stuck in low Earth orbit when its computers failed.
Attempts to restore contact with the spacecraft were unsuccessful, and it crashed into the Pacific Ocean west of Chile in January.
All units of the spacecraft withstood rigorous testing on Earth and functioned properly during the launch, the commission said in its report, but heavy ion bombardment corrupted program code in two components of the probe's computer.
Backup systems to counter such malfunctions should have been installed, Nikolai Vedenkin, a researcher at the Moscow State University who supervises the university's own space program, told RIA Novosti Friday.
"Either the whole system was configured wrong, or it's simply not true," Vedenkin said of the commission's report.
Confusion during its development and testing, which was rushed and saw the lead constructor changed mid-project, were the likely cause for the spacecraft failure, he said.
"The mistakes snowballed, and the probe was launched when still not ready."
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