Technical Error Caused Hard Soyuz Landing

Russian space officials say a technical malfunction is to blame for the hard, off-target landing of a Soyuz spacecraft returning a U.S. and Russian crew from the international space station earlier this month.

Chief investigator Nikolai Zelenshchikov said Monday that the craft began an unusually steep trajectory because of a malfunction in its descent guidance mechanism. Experts found no defects in the craft’s new software and say human error was not a factor in the botched landing.

Mr. Zelenshchikov said the descent mechanism that guided the Soyuz’ re-entry had been in use for over 20 years.

Space officials say they will continue their investigations into the craft’s faulty landing because they have been unable to simulate the system failure. However, they say they have pinpointed changes needed in the guidance mechanism.

Investigators have also recommended changes in the way space officials track returning spacecraft. Mr. Zelenshchikov says the helicopters and planes will be used to follow the landing routes of future capsules. He added that crews will have satellite communication technology.

On May 4 the Soyuz spacecraft returned to Earth after a five-month mission in space. During re-entry, the crew experienced intense gravitational pressure as the craft switched from a controlled to an uncontrolled reentry. The spaceship also landed nearly 500 kilometers from its target area.