MOSCOW -- An engine snag has delayed the arrival of a Russian spacecraft carrying three astronauts to the International Space Station until Thursday.

A rocket carrying Russians Alexander Skvortsov and Oleg Artemyev and American Steve Swanson to the space station blasted off successfully early Wednesday from the Russian-leased Baikonur cosmodrome in Kazakhstan.

The Soyuz booster rocket lifted off as scheduled at 3:17 a.m. local time Wednesday. It entered a designated orbit about 10 minutes after the launch and was expected to reach the space station in six hours. All onboard systems were working flawlessly, and the crew was feeling fine.

NASA and Roscosmos, Russia's space agency, said shortly before the planned docking that the arrival had been delayed after a 24-second engine burn that was necessary to adjust the Soyuz spacecraft's orbiting path "did not occur as planned."

The crew is in no danger, but will have to wait until Thursday for the Soyuz TMA-12M to arrive and dock at the space station, NASA said. The arrival is now scheduled for 7:58 p.m. ET Thursday.

Roscosmos chief Oleg Ostapenko said on Wednesday that the glitch occurred because of a failure of the ship's orientation system. The crew is in good spirits and they have taken off their space suits to prepare for the long flight, Ostapenko said in remarks carried by Russian news agencies.

The Russian official said the crew is now working to adjust the spacecraft to the right orbit to make it for the Thursday docking.

Russian spacecraft used to routinely travel two days to reach the orbiting laboratory before last year. Wednesday would have been only the fifth time that a crew would have taken the six-hour "fast-track" route to the station.

So far, the tensions between the U.S. and Russia over Ukraine have been kept at bay. Since the retirement of the U.S. space shuttle fleet in 2011, NASA has relied on Russian Soyuz spacecraft as the only means to ferry crew to the orbiting outpost and back.

The U.S. is paying Russia nearly $71 million per seat to fly astronauts to the space lab through 2017.