Spacecraft failure delays astronauts' return to Earth

The launch failure of an unmanned Russian cargo spaceship has prompted the nation's space agency to delay both the landing of some of the International Space Station's crew and the launch of their successors, officials said Tuesday.

The chief of the Roscosmos space agency, Igor Komarov, said the April 28 launch mishap was caused by a leak of fuel tanks in the Soyuz rocket's third stage. Left in low orbit, the Progress cargo spaceship fell to Earth over the Pacific on May 8.

The need to pinpoint the cause of the flaw and work out steps to prevent it from happening again has required changes in the schedule of following launches, officials said.

Vladimir Solovyov, the head of the station's Russian segment, said three of the orbiting outposts' six-person crew, who had been scheduled to return this week, were asked to stay in orbit until early June.

"They have accepted it with understanding and agreed to work an extra month or so in orbit," Solovyov said at a briefing.

Replacement crew delayed 2 months

He said the launch of a replacement crew will be pushed back from late May to late July. It will be preceded by the launch of a Progress cargo spaceship in early July to ensure crew safety, Solovyov said.

"In accordance with space and aviation regimen, we can't immediately make a manned launch," Solovyov said.

Both the Soyuz spacecraft that delivers crews to the station and the Progress cargo spaceship are put into orbit by the Soyuz booster rocket, a workhorse of the Soviet and then Russian space program for more than four decades.

Russia's space program has seen a string of launch failures in recent years, which have been linked to defects in workmanship and other human errors. A manufacturing flaw caused the loss of a Progress cargo spaceship in August 2011.

Solovyov said that space officials foresee no further delays beyond the summer. He said that the flight of British soprano Sarah Brightman set for September should go ahead as planned.