Discovery launches -- and relief is on the way

Space shuttle Discovery and its crew of seven astronauts thundered through a blue Florida sky Saturday afternoon on a mission to deliver a Japanese laboratory to the International Space Station and to help fix some nagging plumbing problems on board.

The start of NASA’s 123rd shuttle mission went smoothly; it is expected to dock with the station Monday.

Some of the details of the two-week mission:

The crew

Veteran astronaut Navy Cmdr. Mark E. Kelly, who is married to Rep. Gabrielle Giffords (D-Ariz), is in charge. This is his third shuttle flight and his first as commander. The only other experienced astronaut on board is lead spacewalker Mike Fossum, an Air Force reserve colonel. The rest of the crew are first-time fliers: pilot Kenneth Ham; Karen Nyberg; Air Force Col. Ron Garan; Japanese astronaut Akihiko Hoshide; and scientist Greg Chamitoff.

The mission

Discovery will deliver and install the second of three parts of the laboratory called Kibo, which means hope in Japanese. The $1-billion cylindrical lab is nearly 37 feet long and 14.4 feet in diameter, about the size of a big RV.

At 15 tons, it also is one of the heaviest payloads ever carried by a shuttle.

It will take three spacewalks to install the lab and its robotic arm, which astronauts will use to perform experiments on an exposed platform -- a kind of back porch in space. The platform will be carried to the station next year.

During one spacewalk, the astronauts will try to clean metal shavings from inside a malfunctioning rotary joint that keeps some of the station’s solar panels pointed toward the sun. Fixing the joint has been a priority since last fall, when an unknown problem caused it to start grinding as it rotated.

An unexpected urgency

The orbiting platform’s main lavatory, located in the Russian segment, is malfunctioning. The two cosmonauts on the station are expected to install a new pump that Discovery is bringing. Until then, the three-member station crew will use the shuttle’s toilet or emergency bags.

Remaining missions

There are only 10 more flights before the shuttle is retired, but it is still testing new equipment. Discovery is the first to fly with a new external fuel tank designed to minimize the loss of insulating foam during launches. It was a piece of foam that broke off the fuel tank during liftoff that caused the Columbia disaster in 2003.

Pieces of foam came off Discovery’s tank during Saturday’s ascent, but NASA doesn’t think they pose a threat.