Mission logo for IMAGE. Photo: NASA

NASA is about to launch the first spacecraft dedicated to imaging the Earth's magnetosphere -- an invisible magnetic field surrounding the planet that is strongly influenced by the solar wind.

A Delta II 7326 rocket is scheduled to launch the Imager for Magnetopause-to-Aurora Global Exploration, or IMAGE, satellite into orbit March 25 from the Western Range at Vandenberg Air Force Base, CA. The eight-minute launch window for IMAGE opens at 3:35 p.m. EST (12:35 p.m. PST).

IMAGE is the first of its kind, designed to actually "see" most of the major charged-particle systems in the space surrounding Earth. Previous spacecraft explored the magnetosphere by detecting particles and fields they encountered as they passed through them. This technique limited their "vision" to small portions of this vast and dynamic field, which extends about 40,000 miles on Earth's day side and about 110,000 miles on Earth's night side. It would be similar to attempt understanding the nature of the world's oceans from a single buoy.

Just as taking a photograph of the night sky allows astronomers to count and study millions of stars at once, images returned by the IMAGE spacecraft will provide simultaneous measurements of the densities, energies and masses of charged particles throughout the inner magnetosphere using three-dimensional imaging techniques.

"IMAGE brings to space weather studies the kind of capability that geosynchronous weather satellites have brought to surface meteorology," said Dr. Thomas Moore, IMAGE Project Scientist at NASA's Goddard Space Flight Center, Greenbelt, MD. "We may soon be treated to evening news images of plasma clouds engulfing those weather satellites."

The IMAGE spacecraft undergoes final preparations for launch at Lockheed Martin Missiles & Space. Photo: LMMS

During its two-year mission, the half-ton IMAGE spacecraft will image remote particle populations in the magnetosphere. These "photographs" will then be linked together to make movies in real time. Their rapid two-minute cadence will allow detailed study of the interaction of the solar wind with the magnetosphere and the magnetosphere's response during a magnetic storm, which typically lasts a few days.

"In addition to stored data, IMAGE will implement a real-time down link that the National Oceanic and Atmospheric Administration intends to use for space weather forecasting," said Principal Investigator Dr. James Burch of the Southwest Research Institute (SwRI), San Antonio, TX.

To fulfill its science goals, IMAGE will employ six state-of- the-art instruments along with a data processor. The instruments and their developers are:

• High Energy Neutral Atom (HENA) imager, developed by Johns Hopkins University Applied Physics Laboratory, Laurel, MD
• Medium Energy Neutral Atom (MENA) imager, developed by SwRI
• Low Energy Neutral Atom (LENA) imager, developed by Goddard
• Extreme Ultraviolet (EUV) imager, developed by the University of Arizona, Tucson
• Far Ultraviolet (FUV) imager, developed by the University of California at Berkeley
• Radio Plasma Imager (RPI), developed by the University of Massachusetts at Lowell
• Central Instrument Data Processor (CIDP) developed by SwRI

IMAGE is the first of two Medium-class Explorer missions NASA has scheduled for launch. The total cost of the mission, including spacecraft, launch vehicle and mission operations for the first two years is about $154 million. The IMAGE Project Office at Goddard will manage the mission for NASA's Office of Space Science in Washington, DC, while the principal investigator at SwRI has overall responsibility for the science, instrumentation, spacecraft and data analyses.

Lockheed Martin Missiles and Space of Sunnyvale, Calif. built the IMAGE spacecraft -- which measures 7.38 feet in diameter and 4.99 feet high -- under contract with SwRI. On orbit, the RPI antennas aboard IMAGE will extend 33 feet parallel to the spin axis and 820 feet in four directions perpendicular to the spin axis, making IMAGE the longest spacecraft currently on orbit.