CAPE CANAVERAL, Fla. -- A Russian cosmonaut and two American astronauts are set to taxi up to the International Space Station this week, venturing off on what promises to be the longest tour yet aboard the orbiting outpost.

And once the trio takes command of the complex, the fourth full-time crew of the station will face five-and-a-half-months of work that will require the skills of construction and maintenance workers as well as computer specialists and scientific researchers.

"It's almost like a jack-of-all-trades," said veteran NASA astronaut Daniel Bursch, 44, who will serve as a flight engineer aboard the outpost.

"I mean, there will be some days where I will be a scientist," he said. "And then the next day I may be repairing a box that breaks on the space station, that needs to be repaired... So it'll be a little bit of everything."

Bursch, fellow flight engineer Carl Walz, 46, and incoming outpost commander Yuri Onufrienko, 40, are scheduled to blast off for the station at 7:41 p.m. EST Thursday (0041 GMT Friday) aboard shuttle Endeavour.

Four shuttle astronauts will ferry the Expedition Four crew to the station and then return to Earth Dec. 10 with current commander Frank Culbertson and his two cosmonaut colleagues, Vladimir Dezhurov and Mikhail Turin, the three of whom have been in space since August.

• Outfitting the station's prime U.S. command and control computers with new solid state memory units that will replace hard drives that have proven to be prone to failure.

• Playing host to two visiting shuttle crews and a Russian Soyuz taxi crew, and preparing for the arrival of two supply-filled Russian Progress space freighters.

What's more, the veteran space fliers aim to carry out the most varied set of scientific investigations ever attempted aboard the station.

To that end, the trio plans to devote almost 400 hours to carrying out 65 U.S. and Russian experiments in a wide range of scientific disciplines, including biology, medicine, physics and research that could lead to the production of new drugs to fight human disease.

Senior NASA scientist John Uri calls it "the busiest, most diverse and most complex research program we've ever attempted on the International Space Station."

In training now for four years, Onufrienko, Bursch and Walz all say they have prepared themselves mentally for the long haul and realize that living and working in the isolated confines of the station might be difficult at times.

"To me, I look at this as kind of like a naval deployment, but it's different," said Bursch, a Navy captain who served in the Mediterranean Sea as well as the North Atlantic and Indian Oceans. "It's like taking a naval deployment in your stateroom the whole time with the same one or two other people."

Consequently, Bursch said that while the three men get along well, he fully expects that there will be periodic clashes onboard the outpost.

"I don't think it's a question of if there will be some conflict. I think there will be some conflict. And we've seen a little bit of that while we've been training. But we've all kind of learned how to deal with that," Bursch said.

"If we know that somebody is having a bad day, the things that we may have to do may range from recommending that they go run on the treadmill for awhile, or we just leave them alone for a period of time, and a lot of times that can fix it," he said.

"It's very similar, I think, to the conflicts that we see at home in everyday life. So I fully expect that each of us will have at least one bad day in orbit -- and probably several -- and we'll just have to realize that sometimes we'll just have to leave the other person alone."

Onufrienko and Walz both will be bunking in closet-sized "staterooms" in the station's Russian-built Zvezda Module, which doubles as a command post and crew quarters. Bursch will be staying in a temporary sleep station in the station's U.S. Destiny laboratory.

The three plan to use e-mail and an Internet telephone connection to stay in touch with family and friends, and each will be able to hold family videoconferences during their planned 165-day expedition.

Given the ongoing war on terrorism and the rapidity with which the world has been changing since Sept. 11, the Expedition Four crew also will be getting daily news updates from support teams at Mission Control Centers in both Houston and Moscow.

"One of the things that's going to be happening while we're up there is the Winter Olympics, so we're really interested in getting the information on that international sporting spectacle," said Walz. "Hopefully, that will be good news amongst all the bad news that we've been getting lately."

A married father of three, Onufrienko served aboard Russia's former space station Mir during 1996, chalking up 193 days in space. He was commander of Mir when NASA astronaut Shannon Lucid set a world record -- 188 days -- for the longest stay in space by a woman.

An avid outdoorsman, Onufrienko said he plans to spend his spare time aboard the station tying artificial flies.

"I like to go fishing, but this is not possible in space," the cosmonaut joked.

Walz, a married father of two and lead singer in an all-astronaut band called Max Q, will be taking along an electronic keyboard and also expects to spend some time strumming a guitar that's already aboard the station.

"I play the piano and this will give me a chance to relax a little bit," said Walz, a veteran of three shuttle flights. "And maybe we'll have a little space concert down the line there."

Bursch, a married father of four, is taking a couple of books to read and also might try his hand at a hobby he picked up while training in Russia -- making Shaker-style baskets.

"I've brought a very small amount of weaving material, and probably somebody's going to kill me for mentioning this because somebody's going to say, `Well, we're sending astronauts into space to weave baskets,'" he joked.

Realistically, though, none of the three expects to have much free time.

Station crews generally work 16-hour days, with much of that time devoted to keeping the outpost flying in an orbit 250 miles (400 kilometers) above Earth.

"I know that we're supposed to have some free time that we can use on our own, especially on the weekends," said Bursch, who also has flown on three shuttle missions. "But everything I've heard is that we'll be very, very busy, and that will help the time pass by."

The Expedition Four crew is scheduled to return to Earth May 12 aboard shuttle Endeavour.