Alpha crew extends space stay for weeks

The Alpha crew: Yury Usachev, left, Susan Helms, center, and Jim Voss

By Richard Stenger
CNN

(CNN) -- The residents of the international space station must remain in space an extra month, due to nagging problems with the new robotic arm attached to the orbiting outpost.

The cosmonaut commander and two astronaut crew mates, who arrived at the station in May, will return home aboard a space shuttle in August instead of July, NASA said.

The cause of the delay -- a $1 billion, mobile crane attached to the station that has repeatedly experienced unexplained stiffness in one of its numerous joints during testing.

The space station Alpha crew said during a Friday news conference that they were ready for the extended stay.

"I really do miss my family, my friends, my dog," said NASA's Jim Voss. "(But) we had mentally prepared to stay up here for six months. We expected that there would be some sort of delay. This is not a surprise to any of us."

The 58-foot (17-meter) robot arm, which shuttle astronauts installed in May, is designed to move like an inchworm across the modular complex, attaching itself to various power and computer ports on the outside.

Space station Alpha's new arm hangs in a "V" below the space station

The robot arm has been plagued by technical woes during testing, including a persistent glitch with a backup computer command sequence that controls its shoulder joint.

Voss and cosmonaut Yury Usachev had prepared for the possibility of going outside the space station to replace the control box for the joint. But on Friday, ground controllers said they had pieced together a software patch that should allow CanadaArm2 to work without the problem joint, making the spacewalk unnecessary.

Before finding out late Friday that their services were not required outside the station, Voss and Usachev seemed extremely enthusiastic about venturing beyond the confines of their metallic world.

The two floated around holding their spacesuits during the televised news conference, waving to the camera with the suit hands.

Both men were still set to don the suits next Friday to position a docking cone in the Zvezda service module while a compartment on the module is depressurized. It will be the first spacewalk of any kind for Alpha residents.

But space shuttle astronauts have performed many spacewalks during construction on the multibillion dollar orbiting outpost. And the crew of the shuttle Atlantis was set to take three jaunts into space to attach an airlock to Alpha later this month.

The robotic arm on Alpha is necessary to install the airlock. And its arthritic condition convinced NASA managers to postpone the Atlantis flight back from late June to July.

Ground controllers plan to use that extra time to make sure that their remote prescription cures CanadaArm2.

But the delay in turn pushed back from July to August the scheduled flight of the shuttle Discovery, which will launch with another trio of Alpha residents and return with Usachev, Voss and their crewmate Susan Helms.