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, (818) 354-0850
FOR IMMEDIATE RELEASEOctober 16, 1996
THREE MARS MISSIONS TO LAUNCH IN LATE 1996
The United States and Russia return to Mars this fall with
the launch of three missions destined to explore Earth's
planetary neighbor in greater detail than has ever before been
NASA's Mars Global Surveyor and Mars Pathfinder and Russia's
Mars '96 mission are scheduled for three separate launches in
November and December 1996. Mars Global Surveyor, an orbiter
carrying six scientific instruments to study the atmosphere,
surface and interior of Mars, will be launched Nov. 6. It will
be followed by Russia's Mars '96, an orbiter carrying 12
instruments plus two small landers and two penetrators, which
will lift off Nov. 16. Mars Pathfinder will carry a lander and
small rover robot when it is lofted into space Dec. 2.
Launch of the NASA spacecraft marks the beginning of a new
era in Mars exploration and an ambitious new initiative by the
United States to send pairs of spacecraft to the red planet every
26 months through the year 2005.
NASA's new decade-long program of robotic exploration —
known as the Mars Surveyor program — takes the next step in
expanding scientists' knowledge of Mars. The program is focused
on three major areas of investigation: the search for evidence
of past life on Mars; understanding the Martian climate and its
lessons for the past and future of Earth's climate; and
understanding the geology and resources that could be used to
support future human missions to Mars.
The unifying theme of the Mars exploration program is the
search for water, which is a key requirement for life, a driver
of climate and a vital resource. Early missions will thus focus
partially on finding and understanding the past and present state
of water on Mars. Mars Global Surveyor and Mars Pathfinder will
be the forerunners in this quest, becoming the precursors to a
series of missions that may culminate in the first few years of
the next century with robotic return of a Martian soil sample to
Earth, followed by eventual human exploration.
Continuing Exploration Program
NASA's 1996 missions to Mars further the global explorations
of the planet begun in 1965 with the Mariner 4 mission to Mars
and continued in the mid-'70s by the Viking lander missions.
From earlier investigations, scientists have compiled a
portrait of Mars full of stark contrasts. Mars' surface features
range from ancient, cratered terrain like Earth's Moon to immense
volcanoes that would dwarf Mt. Everest and a canyon that would
stretch across the United States.
Mars' atmosphere is less than 1 percent as thick as Earth's,
but there are permanent polar caps with reservoirs of water ice.
Closeup shots of Mars' terrain resemble that of an Earthly
desert, with surface features that look like river channels
carved long ago by flowing water.
The next step in Mars exploration, according to scientists,
is to obtain an overview of the entire planet and to verify
remote observations with measurements taken from the ground. Mars
Global Surveyor is designed to study the atmosphere, surface and
interior systematically over a full Martian year. The Russian
Mars '96 orbiter has similar objectives, but will also
characterize the uppermost atmosphere and its interactions with
the solar wind.
To obtain "ground truth" -- observations on the surface
verifying those made from space -- the Russian Mars '96
spacecraft will deploy two landers that will touch down in the
northern hemisphere in a region called Amazonis Planitia and two
penetrators that will impact and lodge themselves anywhere from 1
to 6 meters (3 to 20 feet) underground. These probes will furnish
details of the atmosphere and surface at the specific locations
in which they land. NASA is contributing two experiments to Mars
'96: the Mars Oxidation Experiment, which will measure the
oxidation rate of the Martian environment, and the Tissue-
Equivalent Proportional Counter, which will study the radiation
environment in interplanetary space and near Mars.
Mars Pathfinder will deploy a mobile rover that will
characterize rocks and soil in a landing area over hundreds of
square meters (yards) on Mars. Pathfinder's instruments and
mobile rover are designed to provide an in-depth portrait of
Martian rocks and surface materials over a relatively large
landing area, thereby giving scientists an immediate look at the
crustal materials that make up the red planet.
Pathfinder Arrival in July 1997
Although the last to leave Earth, Mars Pathfinder takes a
shorter flight path and will be the first of the three spacecraft
to arrive at Mars, touching down in Ares Vallis on July 4, 1997.
Pathfinder is designed to demonstrate an innovative approach
to landing a spacecraft and rover on the surface of Mars.
Pathfinder will dive through the upper atmosphere of Mars on a
parachute, then inflate a huge cocoon of airbags to cushion its
impact. The spacecraft will collect engineering and atmospheric
science data along its descent to the ground.
The primary objective of the mission is to test this low-
cost method of delivering a spacecraft, science payload and free-
ranging rover to the surface of the red planet. Landers and
rovers of the future will share the heritage of spacecraft
designs and technologies that evolve from this pathfinding
Once on the surface, the lander's first task will be to
transmit engineering and science data collected during descent
through the thin atmosphere of Mars. Then its camera will take a
panoramic image of its surroundings and begin transmitting the
data directly to Earth at a few thousand bits per second. Much
of Pathfinder's mission after this will be focused on collecting
atmospheric and surface composition data, and supporting the
rover by storing and transmitting images captured by its cameras.
Pathfinder's nominal mission lifetime is approximately 30 "sols,"
or Martian days (about the same number of Earth days).
Pathfinder's rover, Sojourner, will be carried to Mars in a
stowed configuration with its chassis and wheels folded up like
an accordion. Once its solar cells are exposed to the Sun, the
rover will power up and stand to its full height before leaving
the lander. Driving off onto the floor of an ancient flood plain
believed to contain a wide variety of rocks, Sojourner will
explore the surface independently, relying on the lander
primarily for communications with Earth.
Mars Global Surveyor and Mars '96
Two months later, NASA's Mars Global Surveyor and Russia's
Mars '96 orbiter will arrive at Mars on September 11 and 12,
At first, Mars Global Surveyor will be in a highly
elliptical orbit and spend four months dipping lower and lower
into Mars' upper atmosphere using a technique called aerobraking
to bring it into a low-altitude, nearly circular mapping orbit
over the poles. By March 1998, Surveyor will be ready to begin
data collection, compiling a systematic database as it surveys
the Martian landscape and photographs unique features, such as
the polar caps and Mars' network of sinuous, intertwining river
Mars '96 carries a dozen instruments and a dozen smaller
devices designed to study the evolution of the Martian
atmosphere, surface and interior. In addition to meteorological
and seismic instruments, the spacecraft carries instruments to
image the Martian surface, explore the chemistry and water
content of rocks and attempt to detect and measure the Martian
The Jet Propulsion Laboratory manages the Mars Pathfinder
and Mars Global Surveyor missions for NASA's Office of Space
Science, Washington, DC. Lockheed Martin Astronautics Inc.,
Denver, CO, is NASA's industrial partner for development and
operation of the Mars Global Surveyor spacecraft. Russia's Mars
'96 is managed by the Russian Space Agency. The Russian Academy
of Sciences, Moscow, Russia, is responsible for the Mars '96