Date: Tue, 23 Feb 1999 11:50:11 -0500 (EST)
From: NASANews@hq.nasa.gov
Subject: WIDE-FIELD INFRARED EXPLORER TO SURVEY STARBURST GALAXIES
Don Savage
Headquarters, Washington, DC February 23, 1999
Lynn Jenner
Goddard Space Flight Center, Greenbelt, MD
Jane Platt
Jet Propulsion Laboratory, Pasadena, CA
RELEASE: 99-25
WIDE-FIELD INFRARED EXPLORER TO SURVEY STARBURST GALAXIES
One of NASA's smallest spacecraft, scheduled for launch
March 1, will tackle a very big cosmic question: What is the
history of star-formation in the Universe?
NASA's first new spacecraft in the Origins Program, the
Wide-Field Infrared Explorer (WIRE), is scheduled for launch at 10
p.m. EST on March 1 from Vandenberg Air Force Base (AFB), CA.
The four-month mission will help understand how and when
galaxies formed, and the subsequent history of star-formation in
the Universe. Answers to these questions will shed a strong light
on the very nature of the Universe.
"In many ways this inaugural mission of NASA's Origins
Program, which will study the birth of star-forming galaxies, will
move us towards our ultimate goals," said Dr. Harley Thronson,
acting director of the Astronomical Search for Origins science
theme at NASA Headquarters, Washington, DC. "One of the Origins
Program's long-term goals is to understand the formation of not
only the Universe, but the galaxies and stars we see everywhere in
the cosmos. WIRE will provide us with a wealth of information,
which will get us closer to understanding how the Universe could
reach the point of forming Sun-like stars and Earth-like planets.
And, WIRE will do that at a very modest cost."
"Our science team will measure how densely filled the
Universe has been with star-forming galaxies during its history,
and how quickly those galaxies have been forming stars," said WIRE
Principal Investigator Perry Hacking of Vanguard Research, Inc.,
Fairfax, VA; NASA's Jet Propulsion Laboratory (JPL), Pasadena, CA;
and a professor at El Camino College, Torrance, CA. "WIRE also
will conduct a search for powerful, dusty quasars in the very
early Universe, shortly after the Big Bang. If found in
significant numbers, these quasars will carry strong implications
about the age and structure of our Universe."
Additional WIRE science investigations will include
detailed inventories of some star-forming regions in our own Milky
Way galaxy; searches for small, substellar objects called 'methane
dwarfs,' which are essentially more massive versions of the planet
Jupiter; searches of nearby stars for leftover debris from planet
formation; a more complete inventory of the asteroid belt, and
much more.
The 561-pound (254-kg) spacecraft will be launched from
Vandenberg AFB on a Pegasus-XL launch vehicle built by Orbital
Sciences Corporation. The launch vehicle is a three-stage, solid-
propellant booster system carried aloft by a Lockheed L-1011 jet
aircraft. The system will be released when the aircraft reaches
an altitude of about 40,000 feet (12,200 meters).
The WIRE instrument consists of a 12.5-inch (30-centimeter)
aperture Cassegrain telescope with no moving parts and a field of
view about the size of the full moon. The telescope is enclosed
within a two-stage, state-of-the-art, solid-hydrogen cryostat,
which will keep the instrument's mirrors cooled to below -436 F.
The cryostat is designed like a thermos bottle, using a vacuum
space between layers of insulation, and uses the sublimation (the
direct transition from a solid to a gas) of frozen hydrogen to
cool the telescope. The telescope must be cold so that its own
heat emission doesn't overwhelm the light that it is trying to
detect from space.
The WIRE observatory will be inserted into an orbit with an
altitude of 340 miles (540 km) above the Earth, and will orbit the
Earth every 90 minutes. The observed data will be stored in the
spacecraft memory and sent to ground stations at Poker Flat, AL,
and NASA's Wallops Flight Facility, VA. From there the data will
be sent to the spacecraft control center at NASA's Goddard Space
Flight Center, Greenbelt, MD, and then on to the science
operations center at the Infrared Processing and Analysis Center
(IPAC), California Institute of Technology, Pasadena, for data
calibration and analysis. The WIRE teaming partner is Space
Dynamics Laboratory at Utah State University, Logan, UT.
WIRE is the last of an initial series of Small Explorers
(SMEX) that have been designed and built at Goddard. The Small
Explorer office has provided the mission, spacecraft, and ground
system engineering and the principal investigator has provided the
scientific instrumentation for these missions.
The WIRE observatory was integrated into a three-axis-
stabilized spacecraft designed, built, and tested by the SMEX
Project Team at Goddard. The telescope assembly is provided to
Goddard by JPL. After an initial checkout period of thirty days
on orbit, scientific operations will be coordinated by JPL through
the science operations center at IPAC.
The SMEX program provides frequent flight opportunities for
highly focused, relatively inexpensive and small space science
missions. Each mission is cost-capped for design, development,
and operations through the first 30 days in orbit. Using modern
technology and management techniques, the program is dedicated to
the forty-year Explorer Program tradition of service to the space
science community.
"The Small Explorer program has produced remarkable
results," said Jim Watzin, Project Manager for SMEX. The SMEX
program already has four spacecraft (SAMPEX, FAST, SWAS and TRACE)
successfully operating on-orbit. "All were completed on schedule
and within or below the program cost constraints," he said. "All
missions differed dramatically from each other in form, function,
and scope. WIRE will be the fifth and final mission developed in
this manner." Future SMEX missions are to be built at the
institution chosen by the principal investigator.
The WIRE Project website is located at:
http://sunland.gsfc.nasa.gov/smex/wire/
The WIRE science website is located at:
http://www.ipac.caltech.edu/wire/
- end -
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