Pentagon Looks to Boeing's Delta IV EELV Booster for Launch Access
When Boeing won the majority of U.S. Air Force contracts to launch
payloads on its new Delta IV rocket against competition from Lockheed
Martin's Atlas V, it looked like Boeing would be in the catbird
seat. The USAF awarded Boeing 22 of the 29 initial Evolved Expendable
Launch Vehicle (EELV) launch awards.
However, the bloom is off the rose because of a soft market for
commercial payload launches and concerns that some in the Pentagon
are considering eliminating one of the two EELV programs-or having
the two programs combined-to save costs.
The loss of the Shuttle Columbia, and the grounding of the remaining
fleet which has deprived the Pentagon of that launch option, has
saved both EELV programs for the time being. For Fiscal 2004,
the Pentagon is asking Congress to provide $617 million for both
Boeing's and Lockheed Martin's EELV programs.
The Delta IV first flew last November, carrying a commercial payload.
Its first launch with a USAF payload came this past March when
the medium-launch-vehicle version of the rocket delivered to geosynchronous
transfer orbit (GTO) the Defense Satellite Communications System
spacecraft DSCS III A3, which provides defense officials and battlefield
commanders with secure voice and high-rate data communications.
Three additional Delta IV launches are planned this year, including
another DSCS III launch, the first launch of Boeing's Delta IV
"heavy" vehicle in a mission for the National Reconnaissance
Office, and the first mission from Boeing's new launch facility
at Vandenberg AFB, California. Current schedules call for four
Delta IV launches in 2004.
The Delta IV family of boosters is composed of five vehicles based
on the Boeing Common Booster Core (CBC) first stage. The rocket's
second stage is derived from the Delta III second stage, using
the same RL10B-2 engine, but with two sizes of expanded fuel and
oxidizer tanks, depending on the vehicle configuration. The second-stage
engine can be restarted in flight so the rocket can deliver payloads
to a wide variety of orbits for single- and multiple-manifest
missions.
The Delta IV's Boeing Rocketdyne-built RS-68 main engine, the
first new-design liquid-fueled engine to be developed in the U.S.
in 28 years, uses supercooled liquid hydrogen and liquid oxygen,
known as cryogenic fuels, to produce 650,000 pounds of thrust
at sea level. It is 30% more efficient than liquid oxygen/kerosene-fueled
engines, and produces only steam as a combustion by-product.
The Delta IV Medium launch vehicle consists of a single CBC first
stage and RS-68 engine and uses the baseline second stage from
the Delta III. It can lift a 17,900-pound payload into low earth
orbit, or 9,285 pounds into GTO.
Delta IV Medium+ vehicles also use the CBC and RS-68 engine, and
are augmented by either two or four strap-on graphite-epoxy solid
fuel rocket motors for boost assist. They can carry from 12,890
pounds to 14,475 pounds to GTO. The Delta IV heavy version is
designed to lift up to 28,950 pounds to GTO. It joins three CBCs
together in parallel, each with an RS-68 engine, and uses a five-meter-diameter
second stage and payload fairing.
The Delta IV is manufactured at a1.5-million square-foot Boeing
factory in Decatur, Alabama.
Delta IV launch and processing facilities are located at Space
Launch Complex 37, Cape Canaveral Air Force Station, Florida,
and Space Launch Complex 6 at Vandenberg AFB. The 130-acre Cape
Canaveral complex, formerly a Saturn rocket launch site until
deactivated in 1971, is the first launch site constructed from
the ground up in the U.S. over the past 30 years. Boeing reconstructed
the Vandenberg site, formerly a space shuttle pad.
