CAPE CANAVERAL, Fla.-- Endeavour and its six astronauts dropped out of orbit and zoomed toward a rare nighttime landing Sunday to end a mission that resulted in the virtual completion of the International Space Station.
The weather almost didn't cooperate.
All day, forecasters said rain and clouds might scuttle any touchdown attempts. But the rain stayed away and the sky cleared as the evening wore on.
Mission Control waited until the last possible minute before giving commander George Zamka the go-ahead to head home.
"It's a great night to land in Florida," Mission Control radioed. Zamka was told to expect some thin decks of clouds, but nothing more.
This was to be the 23rd space shuttle landing in darkness, out of 130 flights. The last time was in 2008 -- by Endeavour.
During their mission -- which spanned two weeks and 5.7 million miles -- the astronauts delivered and installed a new space station room and a big bay window with sweeping views of the Earth.
The new room, Tranquility, will serve as a base for life-support equipment, as well as a gym and restroom. It also holds the seven-windowed dome, quite possibly the most anticipated addition ever made to a spacecraft.
The 10 men and one woman on the shuttle-station complex couldn't get enough of the views out those windows, once the shutters were raised last week.
The two new compartments were supplied by the European Space Agency at a cost of more than $400 million. Their addition brought the 11-year-old space station to 98 percent completion.
All that's left now are four shuttle flights to stock the space station with more experiments, spare parts and supplies. Discovery will make the next trip in early April.
NASA plans on wrapping up the shuttle program this fall, after which the space station will be supplied by craft from Russia, Europe and Japan. The Obama Administration is proposing that commercial rocket companies take a crack at the U.S. ferry side of it, once the three remaining shuttles are retired.
Over at the space station, meanwhile, computer trouble triggered temporary communication blackouts Sunday.
The station's three command and control computers kept malfunctioning throughout the morning, disrupting communication between the crew and Mission Control. Until full contact was restored in late afternoon, the five astronauts had to make do without e-mail and their Internet Protocol phone.
Flight controllers suspect the trouble may be related to computer software in Europe's Columbus laboratory.
To make up for all the inconvenience, Mission Control is giving the crew Wednesday off.