spacetoday.net: Delta 4 Heavy launches NRO satellite

Posted: Sat, Jun 30, 2012, 9:51 AM ET (1351 GMT)
Delta 4 Heavy launch of NROL-15 (ULA)

A Delta 4 Heavy lifted off Friday morning carrying a classified satellite for the National Reconnaissance Office (NRO). The Delta 4 Heavy lifted off from Cape Canaveral, Florida, at 9:15 am EDT (1315 GMT) on mission NROL-15 for the NRO. The launch was delayed by just over three hours because of a series of technical problems with the rocket that halted the countdown with under four minutes before launch. The purpose of the NRO mission has not been revealed, but it some observers speculate that it is a next-generation signals intelligence or "stealth" reconnaissance satellite. The launch was the first Delta 4 Heavy, the most powerful current US launch vehicle, using upgraded RS-68A main engines, which generate about five percent more thrust than the RS-68 engine.