Delta (rocket Family)
Delta is a versatile family of expendable launch systems that has provided space launch capability in the United States since 1960. There have been more than 300 Delta rockets launched, with a 95 percent success rate. Two Delta launch systems – Delta II and Delta IV – are in active use. Delta rockets are currently manufactured and launched by the United Launch Alliance.
Read more about Delta (rocket Family): Delta Origins, Launch Reliability, Delta Numbering System, Future Development