An unmanned Russian space capsule carrying supplies to the international space station failed in a docking attempt, Russian Mission Control and NASA said Friday.
The Progress space capsule, launched from the Baikonur Cosmodrome in Kazakhstan on Wednesday, is carrying more than two tons of food, water and other supplies for the orbiting laboratory. Three Russian and three U.S. astronauts constitute the current crew.
None of the supplies were deemed necessary for the station's immediate survival, and the outpost is well-supplied, said NASA flight commentator Rob Navias.
The spokesman for Mission Control outside Moscow, Valery Lyndin, said only that the failure was because of an unspecified technical problem. NASA said the failure was because of an antenna problem.
Space station commander Alexander Skvortsov said the Progress was "rotating uncontrollably" as it neared the space station, Interfax reported.
But NASA spokeswoman Brandi Dean said the unmanned cargo ship is still in control. It missed the station by about three kilometers; an hour later the cargo ship was 6.5 kilometers ahead of the space station but in the same orbit, she said.
Another docking attempt was likely to be tried within days, said Vitaly Davydov, deputy director of the Federal Space Agency, Interfax reported.
The Russian Progress capsules have been a reliable supply system for the space station, and their importance will increase with the end of the U.S. space shuttle program.
Navias said the loss of the automated docking system on the station "told the Progress essentially to continue on its path and fly past its intended docking target."
There is a backup system that is more active than the passive one that failed, Dean said. That would allow the crew on board the station to guide the unmanned ship themselves.
Russian Mission Control told the crew to go back to normal activities, and the Johnson Space Center repositioned the station out of its docking mode, Navias said.