Litton Industries
has announced that a new Radiation Hardened Power
Distribution Unit (PDU), produced by Litton Advanced Systems of
College Park, Md., is successfully powering Lockheed Martin’s IMAGE
(Imager for Magnetopause-to-Aurora Global Exploration) spacecraft,
which was launched March 25, 2000, from Vandenberg Air Force Base.

NASA News, GSFC Press Release 00-58, May 31, 2000, reported: “All
(IMAGE) spacecraft systems have been successfully deployed and are
operating normally. All scientific instruments are operating as
expected and are returning images.

“Initial pictures from NASA’s IMAGE spacecraft are revealing for
the first time the global ebb and flow of hot, electrified gas
(plasma) around the Earth in response to the solar wind.”

The IMAGE Power Distribution Unit (PDU) is based upon a new
generation of space power systems (250W to 20KW) developed by Litton
Advanced Systems. In addition to managing solar array output, battery
charging, and power distribution to the IMAGE spacecraft and science
payload, the PDU: 1) receives commands from the System Controller Unit
(SCU) over a MIL-STD-1553 serial data bus, 2) reports Health and
Status Telemetry to the SCU over the 1553 bus, 3) controls the Torque
Rod current for the Attitude Control System (ACS), 4) controls power
to the Thermal Subsystem heaters, including payload survival heaters,
and 5) turns the MagLatch relay drivers on and off.

Earlier versions of this modular and software reconfigurable power
system are used on the New Millennium Earth Observing – 1 (EO-1)
Spacecraft and the MAP (Microwave Anisotropy Probe) spacecraft, which
were co-developed by Litton Advanced Systems and Goddard Space Flight
Center under a Space Act Agreement. Litton Advanced Systems was
responsible for all of the spacecraft avionics subsystems for EO-1.

NASA’s IMAGE spacecraft was built, integrated with its payload,
and tested at Lockheed Martin Space Systems in Sunnyvale, Calif.,
under subcontract to Southwest Research Institute (SwRI) of San
Antonio, Texas.

IMAGE, led by Dr. James L. Burch of SwRI, was selected by NASA
under the Medium-class Explorer (MIDEX) program. NASA’s Goddard Space
Flight Center in Greenbelt, Md., manages the IMAGE mission.

The IMAGE observatory is a spin-stabilized spacecraft that
measures 2.25 meters (7.4 feet) in diameter and 1.52 meters (4.99
feet) in height and weighs 494 kg (1,087 pounds) (including
instruments). Viewed from either end, it has the form of a regular
octagon. Arrays of high-efficiency, dual-junction gallium-arsenide
solar cells attached to the spacecraft’s eight side and two end panels
provide power to the scientific instruments and subsystems, which
together require an orbit-average power of 250 Watts. In eclipse,
spacecraft power is supplied by a Super Nickel-Cadmium battery.

Litton is one of the nation’s leading shipbuilders for the U.S.
Navy and the largest builder of non-nuclear ships. Litton designs,
builds, and overhauls surface ships for government and commercial
customers, worldwide.

The company is a leading information technology (IT) contractor to
the U.S. government and provides specialized IT services to commercial
customers and government customers in local/foreign jurisdictions.
Litton provides defense and commercial electronics technology,
components, and materials for customers, worldwide.

With headquarters in Woodland Hills, Calif., the company has more
than 40,000 employees, and is expected to have more than $5 billion
revenue. For more information, visit Litton’s Web site at