The first launch of the Boeing Delta IV Heavy booster in 2003 will be funded by the US Air Force, which will pay $140 million for the flight of an operational or a dummy payload.

The Delta IV Heavy comprises three common-core boosters being developed for the USAF evolved expendable launch vehicle (EELV) programme and an uprated RL-10B-2 Centaur upper- stage engine. It will be able to place 23,000kg (50,600lb) into low Earth orbit (LEO) or 13,100kg into geostationary transfer orbit (GTO) and will be launched from Pad 37 at Cape Canaveral, Florida, and SLC-6 at Vandenberg AFB, California. The booster will take over the heavy role from the Lockheed Martin Titan IV.

The Delta IV Heavy is an uprated version of the Delta IV Medium fleet and is being developed under a $1.38 billion EELV contract from the USAF. The Delta IV Medium and Medium Plus boosters will offer capabilities of 8,100kg-11,500kg to LEO, and 4,210kg-6,565kgto GTO.

The USAF has ordered 21 Delta IV Medium launches comprising mainly Navstar global positioning system satellites and starting with a Defence Satellite Communications System (DSCS) flight in 2002. Two launches will fly USAF weather satellites and Defense Space Programme early-warning spacecraft.

Lockheed Martin also received an EELV contract from the USAF worth $650 million for nine launches which was reduced to seven this year. Lockheed's Atlas V EELV will comprise Atlas III-based boosters capable of flying 3,960kg- 8,650kg to GTO from Cape Canaveral. Plans to develop an Atlas V heavy lift booster have been scrapped. The Atlas V has one firm booking to launch a US Navy Geosat satellite. The Delta IV and Atlas V boosters will eventually replace the Delta III and Atlas III fleet as commercial boosters and have already been assigned to launch NASA satellites.

Source: Flight International