Delta II - Delta II Launches

Delta II Launches

The Delta II system has been used for 151 launches. On September 18, 2007, Delta II completed its 75th consecutive successful launch. This is a record for modern launch vehicles. As of 2012, it is the most reliable launch vehicle in service, which it has been since the presumed retirement of the Tsyklon 2 in 2006. Eight launches took place in 2007.

However, the Delta II system does not have a perfect success record. One mission, the launch of Koreasat-1 in 1995, was a partial failure in which the satellite payload was able to compensate when the launch system placed the vehicle in an incorrect orbit.

Another failure, this time complete, occurred on January 17, 1997, when a Delta II 7925 carrying the first GPS Block IIR satellite, GPS IIR-1, exploded only 13 seconds after liftoff, raining flaming debris all over Launch Complex 17 at Cape Canaveral Air Force Station. No one was injured, and the launchpad itself was not seriously damaged, though several cars were destroyed and a few buildings were damaged. It was later determined that a "17-foot crack" in the rocket booster had caused the failure.