CANOGA PARK, Calif., July 19 /PRNewswire-FirstCall/ -- A new rocket propulsion technology demonstration has marked an important milestone, achieving "mainstage" or constant full-power performance for the first time. Called the Integrated Powerhead Demonstration, or IPD, this development project combines the very latest in rocket engine propulsion technologies. To date, the IPD has conducted 21 of 26 tests and accumulated 300 seconds of operation, up to 100 percent power level at NASA's Stennis Space Center (SSC) in Mississippi. The IPD is being developed through the combined efforts of Pratt & Whitney Rocketdyne, a business unit of United Technologies Corp. (NYSE: UTX)...