WASHINGTON -- The early shutdown of the Delta 4Heavy's propulsion system during the Boeing-built rocket's demonstration launchTuesday prevented three satellites on board from reaching orbit.
The rocket's mainpayload, a sensor-equipped dummy satellite called DemoSat,was dropped too low to achieve orbit due to a shorter than expected first stageburn. Also lost were two experimental nanosatellitesprovided by the U.S. Air Force Research Laboratory.
The Air Force Space& Missiles Systems Center released a statement Wednesday saying thatprimary objectives of the Delta 4 Heavy demonstration were achieved despite theproblems with the rocket's main stage propulsion system. Boeing and the AirForce will spend the next two months reviewing the launch data, according tothe statement. Air Force spokesman Joe Davidson could not be reached at hisoffice Dec. 23 and did not immediately return a call placed to his cell phone.
Preliminary analysisindicates that the rocket's two strap-on Common Core Booster burned out andseparated several seconds early, forcing the rocket's upper stage engine tocompensate for the premature shutdown.
Boeing spokesmanRobert Villanueva said that many flight objectives were achieved but stoppedshort of calling the demonstration a success.
"We do have anoutstanding issue we need to work on before our first operational launch nextyear," Villanueva said Dec. 23.
The Delta 4 Heavy isslated to carry the final Defense Support Program missile launch detectionsatellite to orbit in August. A classified National Reconnaissance Officepayload is scheduled to fly aboard the second operational Delta 4 Heavy launchcurrently scheduled to liftoff next December.
The 23-story Delta4 Heavy rocket, a heavy-lift variant of the Delta 4 family, liftedoff from its launch pad at Cape Canaveral Air Force Station in Florida on Dec. 21 at 4:50 p.m. (2150 GMT). The flight hadbeen delayed three times this month due to weather and technicalglitches.
Boeing developed theDelta 4 Heavy rocket as part of the Evolved Expendable Launch Vehicle(EELV) program run by the U.S. Air Force, which paid at least $140million for the demonstration space shot, according to the FAA.