Discovery just hours before launch, under clear Florida skies that surpassed earlier expectations. Credit: NASA
NASA’s space shuttle discovery launched successfully from Cape Canaveral Air Force Base at 7:43 p.m. (EDT) on Sunday, under flawless skies and without a single significant complication, despite past issues that had postponed the launch no less than five times.
Less than a minute after leaving the launch pad, Discovery was traveling 365 miles (578 kilometers) per hour. Less than two minutes after that, the craft was speeding away at 1,100 miles (17,000 kilometers) per hour and climbing, toward the International Space Station.
All three main engines performed perfectly throughout Discovery’s flight. Eight minutes after launch, the twin solid rocket boosters burned out and fell away as the craft was traveling 17,500 miles (28,000 kilometers) an hour.
Now that it’s orbiting Earth, it will take Discovery about two days to catch up to the International Space Station.
Early Sunday afternoon, Launch Director Mike Leinbach sent a “red team” to launch pad 39A to manually correct a valve issue that caused a drop in helium pressure. But following that minor adjustment, NASA encountered no issues to delay the launch.
In fact, the weather improved as the day went on. Original weather predictions had been 80 percent favorable for launch, but by 6 p.m. that prediction had been upgraded to 100 percent.
Discovery’s payload includes technology to boost the station’s power capacity in line with doubling the size of the ISS crew from three to six in May.
The set of solar arrays that the STS-119 crew will be bringing up includes two solar array wings, each of which has two 115-foot-long arrays, for a total wing span of 240 feet, including the equipment that connects the two halves and allows them to twist as they track the sun. Altogether, the four sets of arrays can generate 84 to 120 kilowatts of electricity – enough to provide power for more than 40 average homes. Since the three existing arrays can handle the majority of the station’s day-to-day operational and life support needs, the newest solar array will double the amount of power available for scientific research.
The Discovery crew has been bouncing between NASA’s Kennedy Space Center, in Florida, and the Johnson Space Center in Houston since late January; the first launch attempt was scheduled for early February. But four times, managers rescheduled the launch based on their concern following a hydrogen control valve malfunction on the shuttle Endeavour last fall. They wanted to rule out any similar glitches on Discovery.
Things were looking good for the fifth attempt on Wednesday — when skies would have been clear across much of the east coast — but a leak during refueling led to another cancellation.
Fueling of Discovery’s tank — with nearly 500,000 gallons of chilled liquid oxygen and hydrogen propellants – went off Sunday morning without a hitch.
Discovery’s flight is STS-119, but NASA has actually flown 131 missions with shuttles. Under the Obama administration, the shuttle program is expected to retire next year.
