CAPE CANAVERAL, Florida - Spacewalking astronauts released a ham radio satellite outside the International Space Station on Wednesday despite a missing antenna that will hamper operations.

Russian Sergei Volkov let go of the boxy 57-pound (26-kilogram) satellite with his gloved hands, a few hours after Mission Control had put the operation on hold. But he and his spacewalking partner, Alexander Samokutyaev, ran out of time before they could accomplish the major task: moving a Russian cargo crane from one part of the space station to another.

Soon after the 6{-hour spacewalk began, the astronauts and flight controllers realized one of two antennas had somehow broken off the satellite. Experts on the ground have no idea how it may have broken or when, said NASA spacewalk commentator Josh Byerly.

After debating for three hours what to do, Mission Control instructed Volkov to release the satellite.

The transmitting capability will not be affected by the loss of one antenna, but the receiving of signals from the ground will be degraded, Byerly said. The satellite is designed to operate for a couple of months, and will re-enter the atmosphere and burn up in about nine months.

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 cameras for transmitting Earth views, as well as a student experiment to measure atmospheric pressure.

A Russian cargo ship launched the satellite to the 240-mile-high (386-kilometer-high) outpost in January.

The transfer of the cargo crane _ a three-hour task _ was moved to a future spacewalk; the next one isn't until February.

Before going back inside, the spacewalkers photographed portraits of three Soviet space program heroes that have adorned the inside of the space station since the very beginning: Gagarin, chief spacecraft designer Sergei Korolyov and rocketry pioneer Konstantin Tsiolkovsky. They took the portraits out into the vacuum of space as a symbolic gesture, and took numerous shots, waiting to get as much of Earth in the background as possible.

"Last picture," Mission Control ordered. "Done," came the reply.

Six men currently live aboard the space station: three Russians, two Americans and one Japanese.