CAPE CANAVERAL, Florida – After finding a break in the rainy weather at two U.S. landing sites, the shuttle Endeavor descended to a landing in Florida late Sunday to end a two-week mission that pushed the long running assembly of the International Space Station close to completion.
The shuttle's high speed glide to Earth ended with a touchdown at NASA's Kennedy Space in Florida at 10:20 pm EST (0320 GMT Monday).
Endeavour's successful delivery of Tranquility, the final US habitable module, leaves NASA with just four more shuttle missions to finish the station's outfitting.
The last of the flights, set for late September, will bring a 12-year effort by the United States, Russia, Europe, Japan and Canada to a close.
"Congratulations on a great mission," Mission Control radioed the six astronauts as the shuttle rolled to a stop.
"It's great to be home," said Endeavour commander George Zamka. "It was a great adventure."
The forecast for rain showers and low clouds at both Kennedy and the shuttle's backup runway at Edwards Air Force Base, California, seemed to offer little hope of a landing Sunday.
But Norm Knight, the NASA flight director who supervised Endeavour's landing from Mission Control, urged his team to put aside thoughts of the gloomy forecast, recalling successful landings when the outlook was just as bleak.
After installing Tranquility, the shuttle astronauts worked with the five astronauts on the station to equip the new module with critical life support systems, exercise equipment and a roomy observation deck.
They also revived the station's water recycler. The system that recovers drinking water from urine and moisture in the breathing air is a crucial part of plans to keep the station staffed with a half-dozen astronauts when the shuttle is no longer available to deliver supplies.
The new observation dome surrounds a control post for a robot arm that will play a crucial role in the docking of the commercial capsules that NASA expects to take over the cargo deliveries.
The roomy dome also offers those living aboard the station unprecedented views of the Earth below.
"Arguably, mankind has been after this view for centuries, this perspective, this view of the world," said Zamka after his crew completed the Tranquility 's installation with three spacewalks. "We finally have it, and we will take advantage and enjoy it."
US President Barack Obama doted over the new Earthly panoramas from the observation deck when he spoke with Zamka and his shuttle colleagues, Terry Virts, Steve Robinson, Kay Hire, Bob Behnken and Nicolas Patrick.
The latest additions pushed the station's mass beyond one million pounds, or 98 percent of the final weight, and go 90 percent of the volume anticipated at the end of assembly.
"It's an amazing facility, and it's very rewarding for all of us to be here at this stage, as we transition from assembly to full utilization," said NASA astronaut Jeff Williams, the station's current commander.
"We all look forward to reaping the benefit of the utilization over the next 10 years or so."
Just days before Endeavour's departure, Obama presented Congress with a plan to overhaul NASA, including the controversial cancellation of the agency's Constellation lunar exploration program.
The overhaul includes plans to extend station operations through at least 2020, a four-year extension that was quickly endorsed by NASA's international partners.
Early Sunday, the station's command and control computers experienced a series interruptions. The episode left leaving Williams' crew temporarily unable to communicate with Mission Control, a reminder of the station's isolation.
The problem seemed to be resolved Sunday afternoon, but the cause of the difficulties had not been clearly identified.
The station's life support systems were not affected.
The remaining shuttle flights will stock the stock the station with research gear and spare parts, much of it equipment that is too large for other spacecraft.
The next shuttle mission, which will be flown by a crew of seven US and Japanese astronauts aboard Discovery, is tentatively scheduled to lift off on April 5.
Discovery will deliver science gear to the station's US science module.
Endeavour's final flight is scheduled for a July 29 lift-off. Astronauts will deliver the Alpha Magnetic Spectrometer, an external station observatory for studies of cosmic rays, dark matter and anti-matter.
© AFP 2013