NASA’s Space Infrared Telescope Facility Launched Successfully

NASA’s Space Infrared
Telescope Facility (SIRTF), built, integrated and tested at Lockheed Martin
facilities in Sunnyvale, California, roared into space this
morning at 1:35 am EDT from the NASA Kennedy Space Center in Florida. SIRTF’s
Cryogenic Telescope Assembly, which includes the scientific instruments, was
built by Ball Aerospace in Boulder, Colo., and was delivered to Lockheed
Martin Space Systems in Sunnyvale in February 2002 and integrated with the
Lockheed Martin-built spacecraft. Lockheed Martin Space Systems is also
providing mission support for SIRTF spaceflight operations in conjunction with
the Jet Propulsion Laboratory (JPL) and the California Institute of
Technology.

“We are extremely proud of our decades of work on behalf of NASA, and such
a key role in NASA’s newest space observatory,” said John Straetker, Lockheed
Martin SIRTF program manager. “It is particularly satisfying for our team to
see SIRTF off on its way into deep space to begin its historic mission.”

SIRTF is a cryogenically cooled space observatory that will conduct
infrared (IR) astronomy during a two and one-half-to-five year mission. SIRTF
completes NASA’s family of Great Observatories, which also includes the Hubble
Space Telescope, the Chandra X-Ray Observatory and the Compton Gamma Ray
Observatory. The SIRTF program, a cornerstone of NASA’s Origins Program, is
managed by JPL for NASA’s Office of Space Science in Washington DC.

The spaceborne SIRTF observatory comprises a 0.85-meter diameter telescope
and three scientific instruments capable of performing imaging and
spectroscopy in the 3-180 micron wavelength regime. Incorporating the latest
in large-format infrared detector array technology, SIRTF will provide more
than a 100-fold increased in scientific capability over previous IR missions.
Cornell University, University of Arizona, and the Harvard-Smithsonian Center
for Astrophysics have provided the instruments for SIRTF.

An important feature of the SIRTF mission is the adoption of a solar
orbit. To reach this orbit, the spacecraft was launched on a Delta 7920
launch vehicle with slightly greater than terrestrial escape velocity. The
resulting orbit will have SIRTF trailing the Earth in its orbit around the
Sun. This orbit makes better use of launch capability than would many
possible alternate orbits that would have kept SIRTF in orbit around the
Earth. It permits excellent, uninterrupted viewing of a large portion of the
sky without the need for Earth-avoidance maneuvers. In addition, the absence
of heat input from the Earth provides a stable thermal environment and allows
the exterior of the telescope to reach a low temperature via radiative
cooling.

A one meter-diameter transmitting antenna fixed to the bottom of the
spacecraft will be used twice each day to transmit 12 hours of stored science
data to stations of NASA’s Deep Space Network. In this manner, an adequate
average data rate of 85 kbps — corresponding to one image from SIRTF’s
largest array every 10 seconds — can be maintained over the lifetime of the
mission.

SIRTF’s scientific potential is rooted in four basic physical principles
that define the importance of infrared investigations for studying
astrophysical problems:

— Infrared observations reveal cool states of matter: Solid bodies in
space — ranging in size from sub-micron-sized interstellar dust grains
to giant planets — have temperatures spanning the range from 3K to
1500K (above which nearly all solids evaporate). Most of the energy
radiated by objects in this temperature range lies in the infrared part
of the spectrum. Infrared observations are therefore of particular
importance in studying low-temperature environments such as dusty
interstellar clouds where stars are forming and the icy surfaces of
planetary satellites and asteroids.

— Infrared observations explore the hidden universe: Cosmic dust
particles effectively obscure parts of the visible universe and block
the view of many critical astronomical environments. This dust becomes
transparent in the infrared, where observers can probe optically
invisible regions such as the center of the Milky Way (and other
galaxies) and dense clouds where stars and planets may be forming. For
many objects — including dust-embedded stars, active galactic nuclei,
and even entire galaxies — the visible radiation absorbed by the dust
and re-radiated in the infrared accounts for virtually the entire
luminosity.

— Infrared observations access unique spectral features: Emission and
absorption bands of virtually all molecules and solids lie in the
infrared, where they can be used to probe conditions in cool celestial
environments. Many atoms and ions have spectral features in the
infrared that can be used for diagnostic studies of stellar atmospheres
and interstellar gas, exploring regions that are too cool or too
dust-enshrouded to be reached with optical observations.

— Infrared observations reach back to the early life of the cosmos: The
cosmic redshift which results from the general expansion of the
universe inexorably shifts energy to longer wavelengths in an amount
proportional to an object’s distance. Because of the finite speed of
light, objects at high redshift are observed as they were when the
universe and those objects were much younger. As a result of the
expansion of the universe, much of the optical and ultraviolet
radiation emitted from stars, galaxies, and quasars since the beginning
of time now lies in the infrared. How and when the first objects in
the universe formed will be learned in large part from infrared
observations.

Apart from a few windows at short wavelengths, all of the infrared
radiation emitted by the above objects is absorbed by Earth’s atmosphere.
Worse, the infrared emission of the atmosphere itself blinds astronomers
peering through those windows. Hence the need for a cooled space-based
infrared observatory with high sensitivity — SIRTF.

NASA’s Origins Program follows the chain of events that began with the
birth of the universe at the Big Bang. It seeks to understand the entire
process of cosmic evolution from the formation of chemical elements, galaxies,
stars and planets, through the mixing of chemicals and energy that cradles
life on Earth, to the earliest self-replicating organisms and the profusion of
life. In short, Origins hopes to answer the fundamental questions: Where did
we come from? Are we alone?

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.

For additional information, visit our website:
http://www.lockheedmartin.com.

CONTACT: Media, Buddy Nelson, +1-510-797-0349, or buddynelson@mac.com,
for Lockheed Martin Space Systems Company.