Press Release

Boeing Inertial Upper Stage Deploys DSP-21 Satellite

By SpaceRef Editor
August 6, 2001
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A Boeing Inertial Upper Stage (IUS) payload delivery
vehicle successfully deployed a Defense Support Program (DSP)
satellite today for the U.S. Air Force from space launch complex 40 at
Cape Canaveral Air Force Station.

The mission, DSP-21, was launched aboard a Titan IVB-31 expendable
launch vehicle. Liftoff occurred at 3:28 a.m. EDT and acquisition of
the DSP spacecraft from Air Force ground tracking stations confirmed
the satellite is operating normally.

Following separation from the Titan IVB, the Boeing IUS fired its
two stages to propel the spacecraft toward its geosynchronous orbit.
The IUS performed roll maneuvers to protect the DSP spacecraft from
extreme heat and cold temperatures prior to spacecraft separation.
Upon reaching its intended orbit, the IUS successfully deployed the
TRW-built 5,200-pound defense satellite.

“The successful mission of DSP-21 is another achievement for the
Boeing IUS team,” said Paul Bay, Boeing IUS program manager. “We are
proud to continue our important role for the Defense Support Program.”

The Defense Support Program is a satellite surveillance system
that provides the United States and its allies with ballistic missile
early warning and other information related to missile launches,
surveillance and the detonation of nuclear weapons.

“The Boeing IUS is the only fully redundant booster vehicle in Air
Force inventory and the only one capable of successfully placing
nationally critical DSP satellites into orbit,” said Major Deirdre
Healey, U.S. Air Force IUS program manager.

A typical Boeing IUS mission launched from a Titan IVB involves
IUS separation from the rocket’s second stage booster approximately
nine minutes into flight. The IUS takes over responsibility for the
remainder of the powered portion of the flight. For the next six hours
and 54 minutes, the IUS autonomously performs all functions to place
the spacecraft into its proper orbit, some 22,000 miles above the
Earth. The first IUS rocket burn occurs a little over one hour into
the IUS booster flight. The IUS second solid rocket motor ignites
about six-and-a-half hours into the flight, followed by a coast phase,
and then, separation of the spacecraft.

Since 1983, the Boeing Inertial Upper Stage has successfully
deployed more than 21 critical U.S. defense and interplanetary
satellite missions into high-earth orbits.

Boeing assembles and tests the IUS at its Kent, Wash. facility and
is responsible for spacecraft integration and checkout, ground
operations and launch preparation.

The Boeing IUS can be launched from Titan IV expendable launch
vehicles or the space shuttle. The IUS program is managed by Boeing
Space & Communications.

The Boeing Company, with headquarters in Seattle, is the largest
aerospace company in the world and the United States’ leading
exporter. It is the world’s largest manufacturer of commercial
jetliners and military aircraft, and the largest NASA contractor. The
company’s capabilities in aerospace also include rotorcraft,
electronic and defense systems, missiles, rocket engines, launch
vehicles, satellites, and advanced information and communication
systems. The company has an extensive global reach with customers in
145 countries and manufacturing operations throughout the United
States, Canada and Australia.

SpaceRef staff editor.