HOUSTON (AP) — Two astronauts face a tedious cleaning and lube job Tuesday, the first of a series of spacewalks to resurrect a massive joint that turns one of the international space station’s power-generating solar-panel wings toward the sun.

The 10-foot-wide joint has been clogged with metal shavings from grinding parts for more than a year, limiting how much power the solar wing can produce.

“Yesterday was an exciting day. Today’s going to be just as thrilling, so stay tuned,” called down the space station’s commander, Mike Fincke.

Astronauts Heidemarie Stefanyshyn-Piper and Stephen Bowen began putting on their spacewalking gear Tuesday morning, no easy job in weightlessness. They had a putty knife to scrape away the metal grit in the joint, wet wipes for cleaning and a grease gun to lubricate the area.

“We have a little cleaning and greasing to do, to see if we can make it rotate smoother,” Bowen said Monday. “We’re going to try to make it come back to life.”Other tasks during the 6½-hour spacewalk include moving an empty nitrogen tank into the docked space shuttle Endeavour’s cargo bay for a return to Earth and taking an ammonia hose from the shuttle to store outside the station.

Tuesday’s trip outside the space station is the first of four spacewalks planned during Endeavour’s nearly two-week visit to the space station. The spacewalks are focused on cleaning and lubricating the troublesome joint and lubricating another joint that is rotating without any problems.

“Certainly the first (spacewalk) of any mission is more significant and you want it to go well,” said flight director Holly Ridings.

The spacewalkers spent the night in a depressurized airlock in an effort to purge nitrogen from their bodies and prevent decompression sickness, a painful condition in which nitrogen bubbles form in blood and tissue.

After analyzing images taken during the three days since Endeavour launched Friday from Florida, shuttle officials said there was no need for an extra inspection of the shuttle’s heat shield.

Only a bit more analysis remained before they would be able to clear the shuttle for the ride home with its seven crew members, said LeRoy Cain, chairman of the mission management team.”Endeavour is doing extremely well,” Cain said. “We don’t have any outstanding issues of any significance.”

Using a robotic arm, astronauts moved a 21-foot cargo container from Endeavour and attached it to the space station Monday. Mission Control burst into applause and cheers after shuttle astronaut Don Pettit announced that the hatch had been opened between the station and the cargo container, nicknamed “Leonardo.”

The container holds an extra toilet, refrigerator and kitchenette, exercise machine, sleeping compartments and a new system that recycles urine into drinking water. The newly delivered equipment will allow the space station to increase from its current crew size of three people to six residents next year. The orbiting outpost is on the verge of becoming a two-kitchen, two-bath, five-bedroom home and will have six full bedrooms in a few more months.

Ridings said it would take some time to get the urine recycling system operating safely.”If you imagine doing a major project in your house, there are a lot of complicated details and it can take a while,” she said.

• Mike Schneider