Tim Furniss/LONDON

US Air Force Evolved Expendable Launch Vehicle (EELV) contracts, worth $3.03 billion, have been awarded to Boeing and Lockheed Martin. The Boeing award is worth $1.38 billion and covers a contract for 19 Delta IV EELV launches. Rival Lockheed has won a $650 million contract for nine launches of its Atlas III-based EELVs from Cape Canaveral or Vandenberg AFB.

Each company has also won a $500 million contract for engineering and manufacturing development, but will be expected to invest a significant amount in the development of commercial models of the modular medium and large EELVs, based on common core boosters. A contract for smaller versions is not now expected.

The first launch is expected to be for commercial purposes and will be one of two already planned civil Boeing Delta IV launches of unidentified payloads.

Slotted in between the two commercial launches will be the maiden flight for the US Air Force in 2001. The final choice of the type of EELV models to be covered by the USAF contract has not been confirmed, although Boeing says that two launches in 2003 will be of the Delta IV Large, with three common core boosters. One of the payloads will be a Defence Support Programme early warning satellite.

The 19 Delta IV launches are also likely to include those of Navstar global positioning system Block 2F satellites, 31 of which are manifested for EELV launches between 2000 and 2010. Further EELV contracts, covering launches from 2006, are also expected to be awarded.

Meanwhile, the USAF has cancelled the planned launches of Lockheed Titan 4B boosters from Cape Canaveral on 18 December and 27 January, 1999, while it attempts to find the cause of the momentary power outage that caused the failure of the final Titan 4A booster on 12 August. Until the cause is located, no corrective measures can be taken on the boosters, which are already on Pads 40 and 41 at the Cape.

Boeing says that the failure of the 26 August maiden flight of its Delta III was caused by faulty flight control software in the guidance system, exacerbated by an altered roll pattern of the booster which was caused by unpredicted solid rocket motor dynamics.

Source: Flight International