MOSCOW - A Soyuz spacecraft safely delivered a Russian, an American, and a Dutchman to the International Space Station on Friday, restoring the permanent crew to six members for the first time since September.

But just as concerns over the reliability of the Soyuz have eased, a different version of the Soyuz rocket failed Friday during an unmanned launch, the latest in a string of spectacular launch failures that have raised questions about the state of Russia's space industry.

The craft carrying mission commander Oleg Kononenko, NASA's Don Pettit, and European Space Agency astronaut Andre Kuipers traveled through space for two days after blasting off from Baikonur, the Russian-operated cosmodrome in Kazakhstan. It docked at the station at 5:19 p.m. Friday.

About 21/2 hours later, the three new crew members floated through an opened hatch to join NASA's Dan Burbank and Russians Anton Shkaplerov and Anatoly Ivanishin, who arrived on the station in November. The six crew members will work together until March.

The failed launch of an unmanned Progress cargo ship in August raised doubts about future missions to the station. The next manned launch was delayed until Russian officials could determine the cause of the failure, and it went off without a hitch in November.

But on Friday, a newer version of the Soyuz failed to put a Meridian communications satellite into orbit when launched from Russia's Plesetsk cosmodrome. Space agency head Vladimir Popovkin said the cause was engine failure.