A key
navigation aid from Northrop Grumman Corporation
is supplying attitude reference, or satellite orientation,
information critical to NASA’s Aura Earth Observing System
(EOS) satellite and to a key scientific instrument aboard
it. Precise satellite orientation information will facilitate
Aura’s mission to answer questions about changes in the
Earth’s environment and climate changes.
Aura was launched July 15 from Vandenberg Air Force Base,
Calif. It is on a six-year journey that will help answer
questions about changes in the Earth’s life-sustaining atmosphere.
Science operations will begin approximately three months
after launch, with all onboard scientific instruments becoming
operational in stages over the following three months.
“In addition to supplying information for the spacecraft
stabilization system, our space inertial reference unit
(SIRU(tm)) also supplies information to the primary mirror
stabilization system of the tropospheric emission spectrometer
aboard the spacecraft,” said Alexis Livanos, vice president
and general manager of Northrop Grumman’s Navigation and
Space Sensors Division.
The spectrometer will make the first global measurements
of tropospheric ozone as it measures atmospheric infrared
radiation. It will measure tropospheric carbon monoxide,
methane, nitric acid, water vapor, and nitric oxide. Other
instruments aboard Aura will measure gases such as bromine
oxide, volcanic sulfur dioxide and aerosols as well as ultraviolet
radiation, and special products such as chlorofluorocarbons.
Aura is the third of five satellites launched by NASA for
its first EOS series, following Terra and Aqua, which are
already in orbit. Several of the EOS satellites will fly
in formation to coordinate observations made by different
instruments on the various satellites. Both Aqua and Aura
were built by Northrop Grumman’s Space Technology sector
of Redondo Beach, Calif. and contain the company’s SIRU(tm).
The SIRU(tm) utilizes Northrop Grumman’s exclusive hemispherical
resonator gyros. The inherent high reliability, high performance,
radiation tolerant features of the gyros and the dual redundant
features of the SIRU makes this the ideal inertial reference
unit for long-term missions such as Aura.
The hemispherical resonating gyro utilizes a thin-walled
quartz shell that is energized by an electrical field to
produce an imperceptible vibration pattern within itself.
This pattern is electrically sensed and used to determine
the gyro’s output parameters. The vibration is so minute
that it creates virtually no internal stress and fatigue
effects, leading to its unmatched reliability. Northrop
Grumman is the exclusive producer of the gyros, which to
date have accumulated more than 4.5 million hours of operation
in more than 50 systems in space without a mission failure.
Northrop Grumman’s Navigation and Space Sensors Division,
part of Northrop Grumman’s Electronic Systems sector, supplies
situational-awareness products for international and domestic
defense and commercial markets and offers integrated avionics,
navigation and positioning systems and sensors for space
and high-value platform products, navigation-grade and tactical-grade
inertial systems, fiber-optic gyro systems designed to unique
customer requirements, underwater fiber-optic sensors, identification
friend-or-foe transponders and interrogators, cockpit displays
and computers, and logistic support products and services.
Contact:
Don Barteld
Northrop Grumman Electronic Systems
(818) 712-6179
