Lockheed Martin Satellite Revolutionizes Study of Space Weather
PALO ALTO, CA, July 10th, 2002 -- NASA's Imager for Magnetopause-to-Aurora Global Exploration (IMAGE) satellite, built at the Lockheed Martin Space Systems facility in Sunnyvale, Calif., has made space storms visible to scientists for the first time. IMAGE, launched on March 25, 2000 from Vandenberg Air Force Base, is the first satellite to produce continuous three-dimensional images of the densities, energies and masses of particles in the trillion-cubic-mile volume surrounding the Earth called the magnetosphere. IMAGE's contribution to space weather has been so significant that NASA has extended the lifetime of the mission from two to five years. IMAGE's international team designed seven unique imaging instruments, elements of which were designed and built at Lockheed Martin's Advanced Technology Center (ATC) in Palo Alto, Calif.
The satellite, built for NASA's Explorer program, has shown that the Earth's atmosphere plays a continually changing and active role in diverting and absorbing charged particles streaming from the Sun, known as the solar wind. When strong enough, solar wind interactions present a serious space weather hazard that can disrupt Earth-satellite communications like the Global Positioning System (GPS), which provides crucial navigation information to soldiers in the battlefield, marine traffic, hikers, and automobiles. Effects of strong solar winds also strike closer to home than the upper atmosphere, disrupting radio transmissions and power grids on the Earth's surface.
IMAGE has passed its two-year mark in orbit and brings with it the startling discovery that the Earth's outer atmosphere and solar wind act as a dynamic entity, shielding Earth's inhabitants from the effects of the solar wind. "IMAGE gives the global view for the first time. IMAGE allows us to 'see' geospace for the first time. It's the same as when meteorologists progressed from weather balloons to weather satellites," said Dr. Jim Burch, Southwest Research Institute principal investigator for the IMAGE mission.
IMAGE found that the upper atmosphere (ionosphere) ejects about 100 tons of hydrogen and oxygen into space during each solar storm -- equivalent to six times the volume inside the San Jose Arena -- in order to dissipate the vast amounts of energy flung at the Earth by the Sun. Strong bursts of solar wind are known as solar storms; low-intensity solar storms occur three or four times each week. The ionosphere is the area between 300 and 1,000 kilometers above the Earth's surface.
"That sounds like a lot by human standards, but in fact the Earth's atmosphere is much, much larger than that," said Dr. Stephen Fuselier, co-investigator on IMAGE and manager of the Lockheed Martin Space Physics Department in Palo Alto, Calif., and author of a report on IMAGE findings to be published in the Journal of Geophysical Research. The crucial aspect of the system lies in its timing. The direct input of solar wind energy yields an immediate Earth output - the ejection of part of the atmosphere.
"We knew Earth interacted with space storms, but we had no idea it was so fast, so dramatic," said Fuselier. Although most of the ejected atmosphere is thrown into space, some of it remains trapped in the Earth's magnetic field. Coupled with the high energy of the solar wind, the Earth's atmosphere trapped in the magnetic field creates an enormous, 7000 Â°C, multimillion-ampere electrically-charged gas cloud surrounding the Earth, called the plasmasphere.
"Plasmaspheric tails were predicted and even sampled at single points, but never seen before IMAGE," said. Burch. "Now we know the tails exist, and we have also found, by working with ground-based investigators, that these tails map down to the ionosphere where they can disrupt Global Positioning System signals. This disruption can cause loss of position information if signals from two or more satellites are affected."
"It was a lot of hard work, but it was enjoyable because we were trying to do something very significant, and because I was working with a large team of very intelligent and dedicated scientists, engineers, and technicians," said Burch. "IMAGE has provided us with the first global maps of helium ions surrounding the Earth, the first images of the ring current, the first global images of the protons that bombard the atmosphere, and the first radar maps of ion and electron densities throughout the magnetosphere."
The ATC was a significant contributor to IMAGE's instrumentation. The Palo Alto facility designed and built the star tracker, which helps the satellite orient itself in space, automating a process that was previously done by a controller on the ground. Elements of the Far Ultraviolet (FUV) imager and Low Energy Neutral Atom (LENA) imager were also built and designed in ATC labs. Currently, ATC scientists analyze IMAGE data to better understand the complex dynamics of space weather. IMAGE data are posted in real time on the web and can be retrieved at http://image.gsfc.nasa.gov/.
"I would say the IMAGE experience is a resounding success!" said Dale Vaccarello, Lockheed Martin program manager for IMAGE. "First, it is providing outstanding science at minimum cost to the tax payer. Second, it has provided a successful experience to both scientists and engineers working closely together. Normally a space program can take from 5-10 years to go from contract award to launch. IMAGE took just 3.5 years. This gave everyone on the team a chance to participate in the complete life cycle of a program."
NASA chose IMAGE to be the first satellite in the Medium-Class Explorer (MIDEX) program. The Southwest Research Institute and Lockheed Martin worked jointly to create IMAGE. NASA's Goddard Space Flight Center manages the IMAGE program.
Lockheed Martin Space Systems Company is one of the major operating units of Lockheed Martin Corporation. Space Systems designs, develops, tests, manufactures, and operates a variety of advanced technology systems for military, civil and commercial customers. Chief products include a full-range of space launch systems, including heavy-lift capability, ground systems, remote sensing and communications satellites for commercial and government customers, advanced space observatories and interplanetary spacecraft, fleet ballistic missiles and missile defense systems.
Monica Bobra (650) 424-3108Monica.Bobra@lmco.com