MOSCOW (AP) - A Russian space official on Saturday said U.S. manned space flights could be grounded indefinitely following the loss of the shuttle Columbia and suggested that Russian Soyuz rockets should be used to ferry crews to the International Space Station, a news agency reported.
"It's absolutely obvious that shuttle flights will be stopped, possibly for some years, until the final determination of the cause of the Columbia accident," said Sergei Gorbunov, a spokesman for the Russian Space Agency, the ITAR-Tass news agency reported.
If U.S. shuttles are grounded, only Russian Soyuz rockets would be capable of taking space crews to the International Space Station, or ISS, ITAR-Tass quoted Gorbunov as saying. But he said Russia had very few of the rockets and more would need to be constructed.
Increased use of Soyuz rockets would be a potential windfall for the Russian Space Agency, which has seen its budget shrink drastically since the collapse of the Soviet Union and has sought alternative sources of funding.
Soyuz rockets are currently used to send Russian crews to the space station for short visits and are also used for emergency escape capsules on the ISS. U.S. space shuttles have been used to ferry permanent crews back and forth to the station.
After dumping its Mir space station in March 2001, the Russian space program has concentrated its meager resources on the 16-nation ISS, a U.S.-led project. Russia has sought to earn money by taking "space tourists" to the ISS, who pay vast sums for a trip into orbit.
The Russian Space Agency said that the Sunday launch of a Progress cargo ship to the International Space Station will go forward as planned, despite the tragedy in the United States. The Progress will be launched from the Russian-operated Baikonur Cosmodrome in Kazakhstan.
Meanwhile, Russian cosmonauts began theorizing about what caused the disaster, and some pointed to a possible flaw in Columbia's thermal shield.
Boris Morukov, a Russian cosmonaut who was on an Atlantis space shuttle flight to the ISS in September 2000, said the catastrophe could have been caused by an internal equipment problem, such as an engine explosion, or a flaw in the thermal shield.
"In case of some breach in the thermal shield, the entire structure starts disintegrating," Morukov told Russian ORT television, adding that it fell apart so fast the crew didn't have time to react.
Another Russian cosmonaut, Alexander Laveikin, agreed that the disaster had likely been caused by a problem with Columbia's thermal shield. "Something apparently happened to its thermal insulation," he told TVS television. Veteran cosmonaut Viktor Afanasyev said the thermal shield could have been damaged during lift-off - a fact that may have gone unnoticed by the crew on board, gazeta.ru reported.
The shuttle is essentially a glider during the hour-long decent from orbit toward the landing strip. It is covered by about 20,000 thermal tiles to protect against temperatures as high as 3,000 degrees.
The RIA-Novosti news agency, quoting unnamed officials at the Russian space agency, also said American specialists had underestimated a series of microcracks discovered in the fuel lines of all six shuttles last summer.