New On-Board Engine Lifts Hughes-Built Satellites to Final Orbit
Hughes Space
and Communications Company (HSC) has begun using an innovative,
high-performance engine to boost its satellites toward their final
orbit.
The first use of the engine was in January on the Galaxy XR
satellite, a Hughes 601HP model built for PanAmSat Corporation. PAS-9,
another Hughes 601HP satellite being built for PanAmSat, will also use
this new engine. It is scheduled for launch this year.
Galaxy XR received a 34,000-kilometer (22,000-mile) lift from its
new on-board liquid apogee engine (LAE), built by Kaiser Marquardt of
Van Nuys, Calif. The engine raised the satellite to a circular
geosynchronous orbit after Galaxy XR was successfully placed in an
elliptical transfer orbit (200 km, or 124 miles, at its low point) by
an Ariane 4 rocket Jan. 24. Hughes satellite engineers then put Galaxy
XR through its paces, deploying solar wings and antennas and testing
the payload. They also activated the xenon ion propulsion system
(XIPS), which provides stationkeeping for the satellite.
The new engine provided the heavy lifting with its 445 Newtons
(100 pounds) of thrust, using the standard satellite bipropellants,
monomethyl hydrazine and nitrogen tetroxide. The XIPS uses xenon gas
to provide the small amounts of thrust (17.7 milliNewtons) necessary
to keep the satellite on station during its expected 15 years of
service. (Hughes Electron Dynamics builds XIPS, which has been carried
on Hughes satellites since 1997.)
Kaiser Marquardt calls the apogee engine its High Performance
Thruster, and conducted space qualification tests on the advanced
materials incorporated into this design for Hughes. This particular
design is exclusive to Hughes for use on its 601 and 702 series of
satellites.
Because it uses advanced materials, the new, high-performance
engine operates about 700 degrees Fahrenheit hotter than conventional
satellite engines, resulting in greater propellant efficiency and
higher performance. It provides a specific impulse of approximately
322 seconds as compared to the 315 seconds provided by standard apogee
motors used by HSC. This means less fuel is required to reach
geostationary orbit, which in turn results in reduced launch cost,
increased payload mass capability, increased satellite life or any
combination thereof. The benefits vary with the satellite’s mission
and the launch vehicle used. For example, it could allow about a
120-pound payload or satellite mass increase for a Hughes 601
satellite.
Besides using the new boost engine, Galaxy XR is also the first
spacecraft to fly Propellant Management Device (PMD) tanks employing
the HSC-patented etched disk concept. The PMD consists of a series of
paper-thin metallic disks placed in a stack and used to draw
propellant out of the tank. The robust, lightweight PMD design
provides gas-free propellant delivery during spinning as well as
zero-gravity mission phases with substantial margins. It results in
greater operational flexibility for the spacecraft.
Dowty Space Projects of the United Kingdom designed, developed,
qualified and built the tanks to HSC’s specifications.
“Hughes is dedicated to maintaining our technology leadership role
in the industry, and to applying that technology to add value for our
customers,” said HSC President and CEO Tig H. Krekel. “And we rely on
top-quality suppliers such as Kaiser Marquardt and Dowty to keep us on
the leading edge.”
HSC is the world’s leading manufacturer of commercial
communications satellites, having built nearly 40 percent of those in
operation. It also is a major supplier of spacecraft and equipment to
the U.S. government, and a builder of weather satellites for the
United States and Japan. HSC is a unit of Hughes Electronics
Corporation.
PanAmSat, based in Greenwich, Conn., is a leading
provider of global video and data broadcasting services via satellite.
The company builds, owns and operates networks that deliver
entertainment and information to cable television systems, TV
broadcast affiliates, direct-to-home TV operators, Internet service
providers, telecommunications companies and corporations. With 21
spacecraft in orbit today, PanAmSat has the world’s largest commercial
geostationary satellite network. The company will expand its global
fleet to 24 spacecraft by mid-2001. PanAmSat is 81 percent owned by
Hughes Electronics.
Hughes Electronics is the world’s leading provider of digital
television entertainment, and satellite and wireless systems and
services. The earnings of Hughes Electronics, a unit of General Motors
Corporation, are used to calculate the earnings per share attributable
to the General Motors Class H common stock. Visit HSC,
PanAmSat and Hughes at their respective Websites, www.hughespace.com,
www.panamsat.com and www.hughes.com.
