Space shuttle Discovery and its seven-member crew landed at 1:53 a.m. BST Saturday at Edwards Air Force Base in California, capping off a 14-day mission to deliver supplies and research facilities to the International Space Station and its six-person crew.

Mission managers called off Friday afternoon’s landing opportunities at Kennedy Space Center in Florida because of thunderstorms and otherwise unstable weather conditions.

Discovery’s arrival completes a two-week flight for Commander Rick Sturckow, Pilot Kevin Ford, and Mission Specialists Pat Forrester, Jose Hernandez, Danny Olivas and Christer Fuglesang. Friday was the 58th day in space for their crewmate Tim Kopra, who launched on shuttle mission STS-127 in July and spent two months on the International Space Station as an Expedition 20 crew member.

"We're very happy to be back on land here in California," STS-128 Commander Rick "C.J." Sturckow said after the astronauts got off the shuttle and surveyed their craft. "It was a great mission and we just want to thank everybody for their support."

The crew of seven astronauts, including former station resident Tim Kopra, will fly to their training base at Johnson Space Center in Houston on Saturday. Meanwhile, technicians at NASA's Dryden Flight Research Center, adjacent to Edwards, will take about a week to get the spacecraft ready for its cross-country flight back to Kennedy atop a modified 747.

2nd Spacewalk underway

Two astronauts are conducting the second of three planned spacewalks during this mission. Mission specialists Danny Olivas and Christer Fuglesang will install a new ammonia tank on the International Space Station and stow a depleted tank for return to Earth.

Olivas and Fuglesang spent the night in the Quest airlock in preparation for the excursion. Mission Specialist Patrick Forrester is serving as the intravehicular officer throughout the 6.5-hour spacewalk, which began at 11:12 p.m. BST Thursday.

The spacewalk activity begins in Discovery’s payload bay where the two spacewalkers will remove the new ammonia tank. They will take a thermal blanket off of the tank and loosen four bolts holding the tank to a cargo carrier. Fuglesang, positioned at the end of the station robotic arm, will hand carry the tank to the truss. Pilot Kevin Ford and Expedition 20 Flight Engineer Nicole Stott will operate the arm for the 30-minute maneuver and other arm operations.

Olivas and Fuglesang will meet at the Port 1 truss to install the tank. They will attach it to the truss with four bolts and connect its fluid lines. Then Olivas will ingress a foot restraint on the truss to remove the depleted tank previously attached to the end of the robotic arm. He will hand it to Fuglesang, who will be on the arm to hold the 1,295-pound tank for the ride to the payload bay.

There, they will install the tank on the carrier rack with four bolts and cover the tank with a thermal blanket. They also will remove a grapple fixture from the tank, to be relocated to the starboard truss for later use.

The remaining crew members will continue unloading the Leonardo cargo module.

Discovery on target to dock with ISS

For the second time in history, thirteen people will be assembled on one spacecraft today to kick-off eight days of joint space operations. Space shuttle Discovery is on track for a docking with the International Space Station just after 3 a.m. BST Monday morning.

Commander Rick Sturckow and Pilot Kevin Ford will perform a few final corrective jet firings to refine the orbiter’s path to the station and poise them for a rendezvous pitch maneuver (RPM) under the station at 1 a.m. While Sturckow performs the “backflip” Expedition 20 Commander Gennady Padalka and Flight Engineer Mike Barratt will take photos from the station. Their photos will be reviewed by experts on the ground for evidence of damage to the shuttle tiles.

Once the RPM is complete, Sturckow will fly Discovery ahead of the space station and slowly back it in to dock to the station. Mating is expected to occur at 3:04 a.m. After hatch opening and a routine safety briefing, the two crews will start their joint operations.

Discovery Lifts Off!

With seven astronauts and a host of experiments and equipment on board, space shuttle Discovery completed a flawless ascent into orbit Saturday morning to begin a two-day chase of the International Space Station.

With Commander Rick "C.J. " Sturckow at the controls, the shuttle lifted off on-time at 04:59 a.m. BST from NASA's Kennedy Space Center in Florida.

The crew will rendezvous and dock with the station Sunday and the crew will begin transferring equipment to the outpost during the 13-day mission.

After flying up on Discovery, Nicole Stott will trade places with station resident Tim Kopra, who went into space last month aboard Endeavour. Equipment and science racks for the orbiting laboratory are riding inside the Leonardo cargo module, which is secured tightly inside Discovery's payload bay.

The module will be lifted out of Discovery and locked onto the station so the crew can transfer the gear efficiently. The treadmill named for comedian Stephen Colbert also is aboard Discovery and destined for the station.

Launch attempt delayed

The mission management team opted to give engineers more time to refine their analysis of a fill-and-drain valve inside Discovery rather than push quickly into a new launch cycle, NASA pre-launch mission management team chairman Mike Moses said."We gave the team a day to go and keep working on it," he said.

The decision moved Discovery's liftoff to Saturday at 04:59 a.m. BST to begin the STS-128 mission to the International Space Station.

Engineers are comfortable that the 8-inch diameter valve will work just fine, but the extra time will be used to polish that conclusion and determine a series of possible steps in case another trouble comes up during a future countdown.

STS-128 Launch Director Pete Nickolenko said preparations are already moving ahead toward Saturday morning's launch, including moving the rotating service structure around Discovery so technicians can replace the Tyvek covers protecting the nose thrusters of the shuttle.

Space shuttle Discovery will carry the Leonardo supply module to the International Space Station during STS-128, along with a new crew member for the station, Nicole Stott.

Commanded by veteran astronaut Rick "C.J." Sturckow, the STS-128 mission crew will deliver refrigerator-sized racks full of equipment, including the COLBERT treadmill, an exercise device named after comedian Stephen Colbert.

Stott will take the place of Tim Kopra, who moved into the station during STS-127. Pilot Kevin Ford and Mission Specialists Patrick Forrester, Jose Hernandez, John "Danny" Olivas and Sweden's Christer Fuglesang round out the crew.

Launch Attempt Failed; Bad Weather

The weather outlook for Friday morning's targeted launch of Discovery calls for a 70 percent chance of acceptable conditions at NASA's Kennedy Space Center in Florida. Liftoff would be at 05:22 a.m.

Meteorologists will watch the conditions carefully throughout the countdown, with the greatest expected concern being for anvil clouds and thunderstorms within 20 nautical miles of the Shuttle Landing Facility. The mission management team will evaluate analysis of a fill-and-drain valve problem before Discovery's massive external tank is loaded with propellant. The valve issue developed during Tuesday's countdown and forced a postponement of the launch of the STS-128 mission.

Launch Delayed

The launch attempt for space shuttle Discovery was called off Tuesday morning because of poor weather in the area. The launch team will make another attempt Wednesday morning at 6:10 a.m. BST.

Space shuttle Discovery will carry the Leonardo supply module to the International Space Station during STS-128, along with a new crew member for the station, Nicole Stott.

Commanded by veteran astronaut Rick "C.J." Sturckow, the STS-128 mission crew will deliver refrigerator-sized racks full of equipment, including the COLBERT treadmill, an exercise device named after comedian Stephen Colbert.

Stott will take the place of Tim Kopra, who moved into the station during STS-127. Pilot Kevin Ford and Mission Specialists Patrick Forrester, Jose Hernandez, John "Danny" Olivas and Sweden's Christer Fuglesang round out the crew.

Launch Preparations Continue..

While space shuttle Discovery’s STS-128 launch preparations continue at Florida’s Kennedy Space Center, the astronaut crew completed its final planned integrated ascent training in Houston at NASA’s Johnson Space Center. Launch is targeted for 6:36 a.m. BST on Tuesday, Aug. 25.

On Friday, shuttle managers approved 18 additional plug pull tests on the orbiter side of the external fuel tank to ensure there are no issues with its intertank region. Engineers at the tank’s manufacturing plant in New Orleans are assessing high-tech X-ray data to ensure protective foam ramps on the tank slated for November’s STS-129 mission show no defects.

The ice-frost ramps (IFR) protect brackets along the external tank from development of ice when super-cold liquid oxygen and hydrogen are loaded prior to launch. Foam loss during the last two shuttle launches from one particular IFR high up on the liquid oxygen tank has led to a detailed examination to determine if it is acceptable to launch Discovery without further work.

Meanwhile, the STS-128 crew Friday conducted its final launch training session integrated with Mission Control before heading into quarantine Monday. They will fly to Kennedy on Wednesday to prepare for launch.