Conference 7.286::space

928.0. "JPL/Wide-Field Infrared Explorer" by 56821::BATTERSBY () Thu Oct 20 1994 14:12

Article: 6544
From: [email protected]
Newsgroups: sci.space.news
Subject: JPL/Wide-Field Infrared Explorer underway
Date: 12 Oct 1994 11:51:46 -0700
Organization: Jet Propulsion Laboratory - Pasadena CA
Sender: [email protected]
 
PUBLIC INFORMATION OFFICE
JET PROPULSION LABORATORY
CALIFORNIA INSTITUTE OF TECHNOLOGY
NATIONAL AERONAUTICS AND SPACE ADMINISTRATION
PASADENA, CALIF. 91109. TELEPHONE (818) 354-5011
 
Contact: Diane Ainsworth
 
FOR IMMEDIATE RELEASE                     October 12, 1994
 
      Starburst galaxies -- vast clouds of molecular gas
cradling the sites of newborn stars -- will be the target of
a new Jet Propulsion Laboratory satellite selected for
flight in 1998 as part of NASA's Small Explorer program.
 
      The new satellite, called the Wide Field Infrared
Explorer, will be a cryogenically cooled, small infrared
telescope designed to study the evolution of starburst
galaxies billions of light-years away, and luminous
protogalaxies -- or infant galaxies -- at much greater
distances.
 
      "Starburst galaxies are galaxies that appear to be
undergoing a burst of star formation," said Dr. Perry
Hacking, principal investigator at JPL and co-inventor of
the telescope along with Dr. Paul Graf of Ball Aerospace in
Boulder, Colo.
 
      "These galaxies represent about 10 percent of the
local galaxy population and account for about 30 percent of
the local energy budget," he said.  "If starburst galaxies
have continued to evolve since they first formed, they may
represent the main source of stars in the universe today."
 
      Most of the luminosity from young, hot stars is
blocked at optical wavelengths by dust and molecular
material enveloping their nurseries. But their luminosity
escapes and can be detected at infrared wavelengths.
 
      For instance, M82 is a typical starburst galaxy in the
constellation Ursa Major, which lies at a distance of about
10 million light-years away. WIRE will be able to detect
galaxies like M82 at 5 billion to 10 billion light-years
away, revealing their evolutionary past. The infrared
explorer will also search for protogalaxies even farther
back in time that are undergoing extremely luminous
starbursts.
 
      JPL has teamed with Space Dynamics Laboratory of Utah
State University in Logan, Utah, to build the infrared
telescope. As envisioned, WIRE will be a simple, 30-
centimeter-diameter (12-inch) telescope with no moving parts
and a field of view about the size of Earth's full moon.
The instrument will require only 35 watts of power and a low
data rate of 9,000 bits per second.
 
       Recent major advances in infrared detector technology
will allow the satellite to detect distant galaxies in the
12- to 25-micrometer wavelength range (12 to 25 millionths
of a meter). The infrared detectors will be supplied by the
Rockwell International Science Center in Anaheim, Calif.,
and the solid hydrogen cryogenic container will be provided
by Lockheed Palo Alto Research Laboratories, Calif.
 
      "The telescope is contained in a lightweight cryostat
-- that's essentially a super high-performance thermos
bottle -- and the optics are surrounded by a jacket of solid
hydrogen," said Dr. Helene Schember, WIRE project manager at
JPL.  "As it melts, the cryostat cools the optics, ensuring
that the telescope feels the heat from distant galaxies."
 
      Using this state-of-the-art technology, WIRE will
survey about 100 square degrees of sky during its four-month
lifetime and amass a catalog exceeding the size of the
existing Infrared Astronomical Satellite (IRAS) Point Source
Catalog.  The satellite will be able to observe starburst
galaxies 500 times fainter at these wavelengths than those
observed by the 1983 IRAS mission.
 
      The telescope will be carried on a three-axis
spacecraft bus designed and built by the Small Explorer
project team at NASA's Goddard Space Flight Center in
Greenbelt, Md. and launched in October 1998 by a Pegasus XL
launch vehicle.
 
      WIRE will be placed in a nearly polar orbit 400
kilometers (248 miles) above the Earth's surface, following
a sun-synchronous path in which the sun will be at the same
point in the sky at the same time each day.  That orbit will
simplify other spacecraft requirements, such as being able
to use a relatively small, fixed solar array and a small
battery to operate the telescope.
 
      The WIRE science team will be composed of astronomers
from Cornell University in Ithaca, N.Y., the California
Institute of Technology and JPL in Pasadena, Calif., the
Goddard Space Flight Center in Greenbelt, Md. and Ball
Aerospace in Boulder, Colorado.  Data processing and
analysis will be performed at the Infrared Processing and
Analysis Laboratory at Caltech.
 
      NASA's Small Explorer Program provides frequent flight
opportunities for highly focused and relatively inexpensive
science missions.  WIRE was one of two missions selected by
NASA in September for development as a Small Explorer
mission.
 
      Design, development and operations of WIRE through the
first 30 days of orbit will cost no more than $50 million.
 
      The mission will be managed jointly by the Jet
Propulsion Laboratory in collaboration with the Goddard
Space Flight Center in Greenbelt, Md., for NASA's Office of
Space Science, Washington, D.C.
 
                            #####
 
 
Note:  An artist's rendering of the WIRE spacecraft is
available as filename WIREREND.GIF at the JPL public access
site, by World Wide Web at http://www.jpl.nasa.gov/, or by
anonymous ftp to jplinfo.jpl.nasa.gov, or by dialup modem to
+1 (818) 354-1333.
 
10/10/94 DEA
#9461