PUBLIC INFORMATION OFFICE
JET PROPULSION LABORATORY
CALIFORNIA INSTITUTE OF TECHNOLOGY
NATIONAL AERONAUTICS AND SPACE ADMINISTRATION
PASADENA, CALIF. 91109. TELEPHONE (818) 354-5011
http://www.jpl.nasa.gov
Contact: Diane Ainsworth
FOR IMMEDIATE RELEASEJune 5, 1996
MARS GLOBAL SURVEYOR DONS ITS SCIENCE PAYLOAD
All six science instruments comprising the scientific
payload of NASA's new Mars Global Surveyor orbiter have been
integrated on the nearly complete spacecraft, which is in
development at Lockheed Martin Astronautics Corp.'s Denver
facility.
The last of the instruments -- the thermal emission
spectrometer -- arrived at Lockheed Martin on May 28, completing
Surveyor's suite of equipment to study the surface, atmosphere
and interior of Mars over a full Martian year, the equivalent of
about 687 Earth days.
"The instruments have been installed on the payload platform
and have undergone initial power-on testing to make sure all of
the electrical connections are working," said Glenn Cunningham,
Mars Global Surveyor project manager at NASA's Jet Propulsion
Laboratory. "The spacecraft has been moved from the assembly area
to Lockheed Martin's Space Simulation Laboratory, where
environmental qualification testing will be completed."
During this phase of testing, Surveyor is being subjected to
simulations of the harsh conditions of launch, Cunningham said.
After completing those tests, the spacecraft will undergo two
weeks of testing in simulations that will replicate the
environment of space -- extremely cold temperatures and
illumination on one side of the spacecraft by the Sun -- to
assure that Surveyor's temperature control design is adequate for
its 10-month journey to Mars and two years in orbit around the
planet.
Mars Global Surveyor carries six of the eight instruments
that were flown on the Mars Observer spacecraft, which was lost
in August 1993. The instruments include: a thermal emission
spectrometer, designed to analyze infrared radiation from the
surface of Mars; a Mars orbiter laser altimeter, which will
measure the height of Martian surface features; and a
magnetometer and electron reflectometer, which will search for
evidence of current and ancient magnetic fields.
Also onboard the spacecraft are a Mars orbiter camera, which
will take high resolution photographs of the planet and provide
daily global weather maps, and an ultra stable oscillator that
will be used along with Surveyor's telecommunications system to
map variations in the gravity field of Mars and study its
atmosphere.
Mars Global Surveyor also will carry a Mars relay radio
system that will be used to support the Russian Mars '96 mission,
planned for launch in late 1996. The relay system will
periodically receive and relay data from instrument packages
deployed to the Martian surface by the Russian Space Agency.
Of the six science instruments onboard the spacecraft, four
-- the camera, laser altimeter, electron reflectometer and
thermal emission spectrometer -- will be carried on the
spacecraft's nadir panel, along with the relay system. Mars
Global Surveyor will orbit the planet in a low altitude, nearly
circular orbit over the poles of the planet, keeping its nadir
panel continuously pointed at the surface. The spacecraft will
complete one orbit around Mars about every two hours. As the
weeks pass, Surveyor will create a global portrait of Mars,
capturing the planet's ancient cratered plains, huge canyon
system, massive volcanoes, gigantic channels and frozen polar
caps.
Surveyor's science instruments have been provided by the
following institutions: Hughes Santa Barbara Remote Sensing Inc.,
Goleta, CA, and Arizona State University, Tempe, provided the
thermal emission spectrometer; NASA's Goddard Space Flight
Center, Greenbelt, MD, provided the laser altimeter and
magnetometer; the University of California, Berkeley, and the
Centre National d'Etudes Spatiales, the French space agency,
provided the electron reflectometer; Malin Space Science Systems
Inc., San Diego, CA, furnished the Mars orbiter camera; Johns
Hopkins University's Applied Physics Lab, Laurel, MD, provided
the ultra stable oscillator; and the Centre National d'Etudes
Spatiales furnished the Mars relay radio system.
Mars Global Surveyor will be shipped from Denver to Cape
Canaveral, FL, in mid-August, where it will be fueled, integrated
with the third stage booster of a Delta II expendable launch
vehicle and readied for launch on Nov. 6.
Surveyor will arrive at Mars in September 1997 and spend
approximately five months aerobraking through the Martian
atmosphere to lower itself into the final mapping orbit. Global
mapping operations will begin in March 1998, allowing scientists
to obtain the first extensive record of Mars' surface, atmosphere
and interior.
Mars Global Surveyor is the first of a decade-long program
of robotic missions to Mars, managed by the Jet Propulsion
Laboratory for NASA's Office of Space Science, Washington, D.C.