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Third attempt to launch shuttle Space shuttle lifts off for ISS
(about 4 hours later)
Nasa is set for a fresh attempt to launch the US shuttle Discovery for a mission to the International Space Station (ISS). Nasa has launched the US shuttle Discovery for a mission to the International Space Station (ISS), with seven astronauts on board.
Two previous attempts to launch the orbiter have been postponed by a mix of bad weather and a technical glitch affecting its main propulsion system. It lifted off from the Kennedy Space Center in Florida at 2359 EDT Friday (0359 GMT Saturday).
Lift-off from the Kennedy Space Center in Florida is now scheduled for 1159 EDT Friday (0359 GMT Saturday). Two previous attempts to launch the orbiter had been postponed by a mix of bad weather and a technical glitch affecting its main propulsion system.
Discovery's mission will be the 30th flight dedicated to ISS maintenance.Discovery's mission will be the 30th flight dedicated to ISS maintenance.
It is transporting materials including science equipment and a freezer to store research samples. Science equipment and a freezer to store research samples are among the items on board.
It also carries a new sleeping compartment, an air purification system and a treadmill to help maintain astronauts' health.It also carries a new sleeping compartment, an air purification system and a treadmill to help maintain astronauts' health.
The shuttle entered orbit eight-and-a-half minutes after launch, and is due to arrive at the ISS on Sunday night.
Six sortiesSix sorties
Nasa plans an additional six sorties to the orbiting platform before retiring its re-useable spaceship fleet at the end of next year or early in 2011.Nasa plans an additional six sorties to the orbiting platform before retiring its re-useable spaceship fleet at the end of next year or early in 2011.
Managers had been discussing an early Friday flight but decided to give their engineers an extra 23 hours to study the hydrogen stop-drain fuel-valve problem that thwarted the second launch effort on Wednesday.Managers had been discussing an early Friday flight but decided to give their engineers an extra 23 hours to study the hydrogen stop-drain fuel-valve problem that thwarted the second launch effort on Wednesday.
Engineers now believe the unexpected signals they were getting from the propulsion system while filling the orbiter's giant external tank on Tuesday were related to a errant sensor.Engineers now believe the unexpected signals they were getting from the propulsion system while filling the orbiter's giant external tank on Tuesday were related to a errant sensor.
Engineers needed more time to tackle a technical glitchEngineers needed more time to tackle a technical glitch
Heavy rain and lightning had intervened at the first launch attempt on Tuesday morning.Heavy rain and lightning had intervened at the first launch attempt on Tuesday morning.
Nasa has until 30 August to get Discovery away before standing down the mission to allow the US Air Force to conduct military satellite operations in the Cape Canaveral area.
If that happens, the next flight opportunity for the shuttle would not be until 17 October.
The big gap is due to congestion at the space station, with Japan's new cargo ship due to make its maiden voyage to the ISS in the middle of September, and a Russian Soyuz craft expected to carry a new crew and space tourist a couple of weeks later.
Discovery's 13-day mission is scheduled to include three spacewalks to replace exterior science experiments, prepare the platform for the arrival of a new module next year, and to install a new ammonia storage tank and return the used one.Discovery's 13-day mission is scheduled to include three spacewalks to replace exterior science experiments, prepare the platform for the arrival of a new module next year, and to install a new ammonia storage tank and return the used one.
Ammonia is used to move excess heat from inside the station to the radiators outside.Ammonia is used to move excess heat from inside the station to the radiators outside.
Discovery will also drop off US astronaut Nicole Stott for a three-month stay on the ISS, and pick up colleague Tim Kopra for the ride home. Kopra has been living on the platform for the past six weeks.Discovery will also drop off US astronaut Nicole Stott for a three-month stay on the ISS, and pick up colleague Tim Kopra for the ride home. Kopra has been living on the platform for the past six weeks.
The mission is commanded by Rick Sturckow.The mission is commanded by Rick Sturckow.