(AP) -- Flight controllers halted the release of a ham radio satellite outside the International Space Station by a pair of spacewalking astronauts Wednesday because one antenna may be missing.
Russian Sergei Volkov took the boxy 57-pound satellite out with him as he emerged from the space station. He was all set to let it loose with his left gloved hand when Mission Control outside Moscow called off the operation.
TV images showed only one antenna sticking out of the boxy satellite. There were supposed to be two antennas, said NASA spacewalk commentator Josh Byerly.
Mission Control directed Volkov and his spacewalking partner, Alexander Samokutyaev, to continue with other work as experts on the ground debated whether the satellite could be released later in the excursion or whether it would have to wait until another day.
Half the data would be lost if the satellite is deployed with a single antenna, Byerly said. If the astronauts take the satellite back in and search for the missing antenna, the release would be put off until early next year. That's when the next spacewalk is scheduled.
The mini satellite is a prototype for a series of educational satellites under development by Radio Amateur Satellite Corp., NASA and a Russian aerospace company.
It holds radio messages marking this year's 50th anniversary of the launch of the first spaceman, Soviet cosmonaut Yuri Gagarin. It also has a beacon for tracking Morse code and a student experiment designed to transmit Earth views.
Mission Control told Volkov to secure the satellite to a handrail and go ahead with the installation of an experimental laser-based transmitting system, about the size of a barbecue pit.
"Will do," Volkov replied.
A Russian cargo ship launched the satellite to the orbiting outpost in January.
Also on the spacewalkers' to-do list: retrieve an old space station antenna and an experiment, and move a Russian cargo crane from one part of the space station to another.
Four other men are aboard the space station: two Americans, one Japanese and one other Russian.
Explore further: Europe postpones launch of first 'space plane'