CAPE CANAVERAL, Fla. -- Space shuttle Endeavour undocked from the international space station Monday and headed for home with the one American and two Russians who spent the past six months aboard the orbiting outpost.
"We promise to take good care of space station," astronaut Donald Pettit told its departing commander, cosmonaut Valery Korzun.
Before leaving, shuttle skipper James Wetherbee urged Pettit to try to keep his sense of humor during the long stretch ahead. "Oh, I will," Pettit assured him.
Endeavour is due back on Earth on Wednesday, though storms are forecast for Cape Canaveral and could delay the long-overdue homecoming for Korzun, cosmonaut Sergei Treschev and astronaut Peggy Whitson.
They spent an extra 1 1/2 months aloft because of various shuttle problems; Monday was their 180th day in orbit.
The space station's three new occupants are Pettit, astronaut Kenneth Bowersox and cosmonaut Nikolai Budarin. Unlike the first five sets of space station residents, they will spend the next four months in solitude, with no one showing up until it is their turn to go home in March.
"It's so much quieter here now, Houston. I don't know what the deal is," Bowersox radioed.
"We're still here with you," Mission Control replied.
"That's good to know," Bowersox said. "We'd be really lonely without you guys."
Endeavour departed after its crew delivered and installed a new $390 million girder on the space station. The two spacecraft separated 250 miles above Australia, ending one week of joint flight.
As Endeavour sailed off into the darkness, Wetherbee wished Bowersox and his crew "fair winds and following seas." Both men are Navy captains.
Bowersox thanked Wetherbee for the ride to the space station. "We wish you a safe landing and warm greetings and hugs from all your friends and families down below," Bowersox called out.
Two of Endeavour's crew performed three spacewalks to hook up the 45-foot girder and correct a design flaw in the air-conditioning lines.
The final spacewalk was especially dramatic. A railcar crucial for station construction got snagged on its tracks by a protruding radio antenna. John Herrington, the first American Indian in space, removed the obstruction and got the railcar moving again.
Released tiny satellites
Once Endeavour was at a safe distance from the space station, the shuttle crew released a pair of 4-inch satellites from a canister in the cargo bay, as part of a Defense Department experiment. The two so-called picosatellites were connected by a 50-foot tether.
Researchers envision such tiny tethered devices being used one day to inspect orbiting spacecraft.
In an interview with Indian Country Today, Herrington said the first time he looked out Endeavour's windows after blasting off Nov. 23, he was amazed at how massive the Earth was -- and how minute the atmosphere. It made him realize "how insignificant we are in the great scheme of things."
Herrington said he carefully chose a variety of American Indian objects to take into space -- eagle feathers, wooden flutes, arrowheads -- "that I think represents a lot of the spiritual sense that we all feel."
He wanted to take tobacco, too, but NASA said no. The 44-year-old astronaut, a Navy pilot, said he recognized NASA's ban but noted: "A lot of folks don't realize that we do use it in a spiritual sense."