Lockheed Martin Trace Solar Telescope Ready for Launch.

VANDENBERG AFB, Calif.--(BUSINESS WIRE)--April 1, 1998--

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Note to editors: Below is the Lockheed Martin Missiles & Space press release on tonight's TRACE solar telescope launch on a Pegasus rocket released from an L-1011 aircraft. The launch will be broadcast live by NASA TV with coverage starting at 5:30 p.m. and the launch scheduled for 6:40 p.m.

A pre-launch press conference will be broadcast by NASA TV also at 11 a.m. featuring TRACE Principal Investigator Dr. Alan Title. For information on tonight's launch or local interviews, contact Dave Waller, 408/742-1606, or Pat Cooper, 408/742-7531. For questions on the program or news release below, call Buddy Nelson, pager 888/916-1797. -0-

The Transition Region and Coronal Explorer (TRACE), a solar telescope designed and built by the Lockheed Martin Missiles & Space Advanced Technology Center in Palo Alto, Calif., is ready for launch. Lift-off is scheduled for April 1 aboard an Orbital Sciences Corporation Pegasus XL rocket from Vandenberg Air Force Base.

NASA selected the TRACE mission for its Small Explorer Program in the fall of 1994. Lockheed Martin's design was among 51 proposals considered. The goal is to provide frequent flight opportunities for focused, inexpensive science missions.

"The Small Explorer program actively embraces the idea of `faster, better, cheaper,'" said Dr. Alan Title, Lockheed Martin scientist and TRACE principal investigator. "The TRACE observatory was funded in early 1995, delivered under budget to our NASA customer just two years later, and today is ready to fly. We built TRACE to very severe cost limitations, and we're very pleased with the outcome. We wholeheartedly support NASA's goal of having lower cost missions, because that's the best way to create frequent flight opportunities."

The objective of the TRACE science investigation is to explore the connections between magnetic fields and plasma structures on the sun. The visible surface of the sun, called the photosphere, averages 6,000 degrees C. Just above the photosphere lies the outer atmosphere of the sun called the corona. The corona is exceedingly hot, ranging from 1 million to 3 million degrees C during calm times, and as high as 100 million degrees during solar flares.

Of considerable interest to solar physicists is the transition region, the interface between the photosphere and the corona. Scientists would like to better understand the mechanism that heats a tenuous corona to millions of degrees while sitting atop a much cooler 6,000-degree photosphere.

"TRACE will follow the energy propagation and heating in the atmosphere," said Title. "Somehow, waves and magnetic fields interact, sending energy into the higher atmosphere of the sun. So what TRACE does is search for these heating channels by looking at the various temperatures in the sun's atmosphere using different kinds of camera filters."

Collaborative observations with experiments in space will add to the wealth of data that TRACE will deliver. Once in orbit, TRACE will join other orbiting solar observatories currently in space: the European Space Agency/NASA Solar and Heliospheric Observatory (SoHO) and the Japanese Yohkoh satellite.

"SoHO has two focuses, one of which is the outer layers of the sun, but also the interior of the sun," explained Title. "We'll be able follow the emergence of magnetic fields from inside the sun, and using the techniques of seismology and tomography, actually be able to see inside the sun.

"Then we will follow the magnetic field emerging through the outer layers of the sun and striking the surface. We'll measure the magnetic field there with SoHO, then follow it through the critical transition region with TRACE. With Yohkoh we'll see it expanding into the corona, and follow it out to 30 or 40 solar radii with the coronographs on SoHO."

In keeping with the short development schedule, the TRACE spacecraft was built using proven components. Three critical mechanisms used on TRACE were developed by Title's team at the Lockheed Martin Advanced Technology Center for use on the Michelson Doppler Imager (MDI) instrument that is flying on the SoHO spacecraft.

"The most sophisticated technologically is the high-speed steering mirror," Title said. "This mirror stabilizes images in the focal plane and greatly reduces the requirements of pointing on the spacecraft. So this component allows us to operate with an attitude control system that has a pointing capability of a few seconds of arc, whereas the images will be stabilized to better than one tenth of an arc second. This component reduces the cost of this experiment and could reduce the cost of any experiment that uses imaging technology.

"In the imaging systems we use filter wheels. For MDI we developed some very thin hollow core motors," said Title. "The motor sits around the periphery of the filter so there isn't a central axle. It has no gears and uses very little power, so it's suitable for any application that has rotary parts. Finally, we have a very nice CCD camera that is applicable to a broad range of applications."

The TRACE telescope mirrors are coated with state-of-the-art normal incidence extreme ultraviolet reflectors. The optics and coating system were developed by Dr. Leon Golub of the Smithsonian Astrophysical Observatory in Cambridge, Mass., and the coatings were applied at the Lawrence Berkeley Laboratory.

TRACE is the first U.S. solar research satellite launched since the Solar Maximum Mission began in 1980. The TRACE instrument, on a NASA Goddard Space Flight Center Small Explorer spacecraft, will be inserted into a sun-synchronous orbit around the Earth.

The orbit has a unique feature vital to the TRACE mission. It moves the spacecraft to the west at the exact same rate that the sun appears to move across the surface of the Earth. Thus, for the first time, a U.S. solar research satellite will observe the sun continuously without occultation by the Earth for part of every orbit.

As an object of study the sun has fascinated scientists for centuries. "The sun is a pretty fundamental thing in our lives," said Title. "Just as a human being, I'm interested in the sun as the source of all life on Earth. It does some pretty remarkable things.

"It has a magnetic cycle and sunspots, and no one knows exactly how they work. It rotates differentially, but we don't understand how. These are quite fundamental properties of stars, and how they operate and why they operate is interesting.

"On another level," added Title, "the sun is just intrinsically beautiful. Anybody, who studies the sun, even casually, is taken by the aesthetics of it. For a scientist, being able to understand why this very beautiful thing behaves the way it does is very satisfying."

The Lockheed Martin Missiles & Space Advanced Technology Center (ATC) is a world-class provider of advanced scientific and space technologies, prototypes, and research for physical, electronic, information/computing, materials, engineering, and electro-optical applications.

CONTACT: Lockheed Martin Missles & Space

Buddy Nelson, 888/916-1797 (pager)