Delta 2 lifts off for 75th straight successful mission

William Atkins
Wednesday, 19 September 2007 20:23

Science - Space

On Tuesday, September 18, 2007 a Delta 2 (7920) rocket lifted a WorldView 1 satellite off the launch pad at Vandenberg Air Force Base in California. The on-time liftoff occurred at 11:35 a.m. Pacific Daylight Time (1835 GMT).         

The “7920” designation represents “7”=7000 series Delta rocket; “9”=number of boosters; “2”=includes a second (2nd) stage (in this case an Aerojet AJ10 engine); “0”= does not include a third (3rd) stage.

The 75 consecutive successful launches of the Delta 2 (or Delta II) make it the most reliable expendable launch vehicle (rocket) currently in operation around the world. The Delta 2 series of rockets has launched 130 times, with only two failures. Its current string of 75 straight successful missions started in May 1997.

It was originally designed and constructed by McDonnell Douglas (with its first launch on February 14, 1989), later built by Boeing’s Integrated Defense Systems, and is now owned by United Launch Alliance, a joint venture by Lockheed Martin and Boeing.

Among its other successful launches have been the Mars Phoenix lander, in 2007, the Mars Exploration Rover (MER), which included the rovers Spirit and Opportunity, in 2003, and the Mars Odyssey in 2001. In addition, the NASA Dawn mission, a robotic probe to asteroids, is currently scheduled to lift off on September 26, 2007, onboard a Delta 2 rocket.

The WorldView 1 is a high-tech 2.5-ton Earth-imaging satellite that can see objects on the Earth’s surface as small as 20 inches (51 centimeterts) in diameter. The satellite is in a polar orbit about 308 miles (496 kilometers) above the Earth. It has the ability to produce images with a 1.6-foot (0.5-meter) resolution of about 290,000 square miles (750,000 square kilometers) of the Earth’s surface each day.

WorldView1 will play an important military role in the U.S. government’s intelligence surveillance of problem areas around the world, along with commercial applications in various fields of interest. Google Earth will be one of its customers.

DigitalGlobe Corporation owns the WorldView 1 satellite. The company is based in Longmont, Colorado, U.S.A. It currently operates the QuickBird satellite, which had been the only commercial spacecraft, up until WorldView 1, to be able to produce sub-meter resolution imagery of the Earth's surface from a position orbiting in space.