HOUSTON Atlantis astronaut Jim Voss is planning on putting some sweat equity into his new homestead, the International Space Station (ISS).

Voss, along with cosmonaut Yuri Usachev and astronaut Susan Helms, is slated to be a member of the second crew to occupy the ISS sometime in 2001.

But before he gets to walk in the front door, on flight day for of shuttle Atlantis mission he and colleague Jeff Williams will pop out of the orbiters airlock to assemble cranes, replace an antenna and install handrails during a six-and-a-half hour spacewalk, or extravehicular activity (EVA).

"Im going to be pretty excited," said Voss, a recently retired Army colonel. "Its been a long time and Im excited about seeing my future home."

Voss, 51, has spent four years training to be an occupant of the station. Before that, he trained in Russia as a backup for astronaut Michael Foales 1997 mission to Mir. Voss performed a spacewalk in 1995 to test spacesuit modifications, as well as tools and procedures used to assemble the ISS.

Though he and other future ISS occupants have been training for spacewalks and living aboard the station, Voss schedule moved up when the space agency split the current servicing mission in February. Voss, Helms and Usachev swapped with three other astronauts for this mission and dove into the accelerated training.

"Were really confident in their skills," said lead EVA officer Scott Bleisath. "Jeff Williams, the lead astronaut, has over a year experience with most tasks and Jim Voss adds quite a bit of previous experience."

Astronauts train to spacewalk at the Johnson Space Center. The center has a 40-foot (12-meter) deep pool called the Neutral Buoyancy Laboratory where the astronauts go through the motions of working in weightlessness. They spend anywhere up to 10 hours practicing for each hour they will actually spend working in space. For this mission, the training ratio was about six hours to one hour.

An astronaut trains for extravehicular activity in the Neutral Buoyancy Tank at Johnson Space Center.

"The training has been quite busy, but thats not unlike the normal shuttle mission," Voss said. "Learning the nomenclature of the items has been the challenge. The tasks themselves are quite simple and not difficult."

Williams, 42, an Army lieutenant colonel, remains from the original crew and has extensive training for ISS assembly spacewalks, though this will be his first trip into space.

"Im going to go out the door and take things slow," he said. "Itll take a while to -- as a Navy guy would say -- get my sea legs."

Inside Atlantis, Mary Ellen Weber joins the EVA team as a critical component operator of the Remote Manipulator System (RMS), or the shuttles robotic arm.

"This whole idea that you can do these robotic operations without being able to directly view your work site, and be able to view the different joints of the arm and to view the different pieces of equipment that we need to avoid, is extremely challenging," Weber said.

Weber will be faced with an additional challenge in that she will have to watch the spacewalkers on video monitors since the station blocks views out the aft flight-deck windows.

"This whole idea that you can do these robotic operations without being able to directly view your work site, and be able to view the different joints of the arm and to view the different pieces of equipment that we need to avoid, is extremely challenging," she said.

Weber likened it to a video game or the virtual-reality training that the space agency has used for training.

Voss said the three of them have worked out a system of commands to move the spacwalking workers safely and efficiently. Commands such as "closer to the structure" and "further away from the structure" will be used rather than "port," "starboard," "up" or "down."

"I was used to working with the station coordinates all this time, but it was very quick to go back to the orbiter system," he said. "We constantly communicate on this so that she knows how close we are and how far we need to move."

First order of business for the EVA team after exiting the airlock will be to set up their tools, foot restraints and safety tethers. Inside Atlantis, pilot Scott Horowitz keeps track of the checklists and keeps the crew on schedule.

Then Voss, perched on the end of the shuttles robotic arm, with Williams riding along, will be moved into position to inspect the U.S.-built crane already on the station.

Ground controllers suspect the crane, known as the Orbital Transfer Device, has come loose since installation last year.

Bleisath said the crane was installed properly, but gave a false indication it was locked in place.

The duo will unhook the latches and try to get them to lock securely. Failing that, theyll go to plan B bringing the crane back to Earth.

"One of our options is to bring it back into the airlock for repair," Williams said. "Our hope is we can just reseat it in place and put it back in the locked position."

After the crane repair, both astronauts move back to the shuttles payload bay to assemble two components of another crane -- the Russian-built "Strella" -- and install it on the station.

The cranes 45-foot (13.7 meter) boom, tether ring and end adapter that holds items to be moved, will be mated to the grapple fixture and base already on the station.

Next on the EVA agenda, the spacewalkers will replace a faulty antenna used for video and telemetry transmission. The task involves removing four cables, releasing the broken antenna and then installing a new 2-foot- (0.6-meter-) long and 1-foot- (0.3-meter-) wide antenna.

If time permits, the spacewalkers have two "get ahead" tasks that arent considered critical to mission success and can be put off until the next visit to the station: Voss and Williams will install eight handrails on the U.S.-built Unity module. Voss also has the task of securing a video cable to the handrail with ties.