Uncertainty clouded International Space Station operations on Thursday after an unmanned Russian supply mission for six astronauts in orbit crashed, unnerving NASA and others that rely entirely on Moscow to ferry crews.
Russia's space agency has kept quiet on its plans and set up a commission to study the crash. But astronauts, experts and foreign space officials said missions should be grounded for the near future until a thorough investigation can help calm fears.
Coming on the heels of a series of costly botched launches, Wednesday's loss of the unmanned craft, which caught fire in the sky before plummeting to Siberia, was a major embarrassment for Russia's industry and sparked a flurry of criticism at home.
Prime Minister Vladimir Putin ordered an overhaul of safety checks on Russia's rockets, and State Duma Speaker Boris Gryzlov said the lower house will review whether "systemic problems or just bad luck" were to blame for the string of failures. Media reports put the cumulative recent losses at more than $553 million.
The unmanned Soyuz-U rocket, which fizzled out five minutes after blasting off from the Baikonur launch pad, closely resembles Russia's Soyuz-FG model used to transport astronauts to the orbital station in the absence of a U.S. shuttle.
The next space station crew launch, which industry sources and foreign officials say will now be postponed from Sept. 22, was to be the first since the U.S. space agency ended its 30-year shuttle program in July.
"For sure it has raised jitters," said Rene Pischel, head of the Moscow branch of the European Space Agency, one of Russia's 15-nation partners in the orbiting station.
"The reason for that is the same launcher is being used for manned launches and in addition to that, you have this sequence of failures. … That, of course, makes everybody very cautious."
A NASA official, speaking on condition of anonymity, said there was uncertainty over the remaining years of the program, and no unmanned, much less, piloted missions, would fly until the problems had been pinpointed, "which will take some time."
In the near term, the catastrophe may delay plans to return U.S. astronaut Ron Garan and cosmonauts Andrei Borisenko and Alexander Samokutyayev to Earth on Sept. 7, after 156 days in orbit. Space officials have said they have enough supplies to remain in orbit for several months.