Douglas Isbell
Headquarters, Washington, DC               September 24, 1996
(Phone: 202/358-1753)

Diane Ainsworth
Jet Propulsion Laboratory, Pasadena, CA
(Phone: 818/354-5011)

RELEASE: 96-192

SECOND NEW MILLENNIUM FLIGHT WILL SEND
MICROPROBES TO THE SURFACE OF MARS

        Two small science probes will be sent to Mars in 1999
to demonstrate innovative new technologies brought to the
forefront by NASA's New Millennium program.

        Under terms of a new agreement between the New
Millennium and Mars Exploration programs, the microprobes
will hitchhike to Mars aboard NASA's 1998 Mars Surveyor Lander.

        "A successful demonstration of the microprobe
technologies will enable a wide range of scientific
activities that would not be affordable with conventional
technologies," said Dr. John McNamee, manager of the 1998
Mars Surveyor Lander and Orbiter project at NASA's Jet
Propulsion Laboratory (JPL), Pasadena, CA.

        "In particular, scientific investigations which
require a relatively large number of surface stations
distributed over the surface of Mars, such as seismic or
meteorology networks, will be made possible by the microprobe
concept," McNamee said. "In addition, microprobe penetrators
may be the most efficient and effective way of obtaining soil
samples and measurements from below the sterilized Martian surface."

         In the process of enabling future characterization
of the Martian climate by a meteorological network, the Mars
microprobes will complement the climate-related scientific
focus of the 1998 Mars Surveyor Lander by demonstrating an
advanced, rugged microlaser system for detecting subsurface
water.  Such data on polar subsurface water, in the form of
ice, should help put limits on scientific projections for the
global abundance of water on Mars.

        Future missions to the planet could use similar
penetrators to search for subsurface ice and minerals that
could contribute to the search for evidence of life on Mars.

        The 1998 Mars Surveyor Lander will be launched in
January 1999 and spend 11 months en route to the Red Planet.
Just prior to its entry into the Martian atmosphere, the
microprobes, mounted on the spacecraft's cruise ring, will
separate and plummet to the surface using a single-stage
entry aeroshell system. Chosen for its simplicity, this
aeroshell does not separate from the microprobes, as have
traditional aeroshells on previous spacecraft, such as the
Mars Pathfinder and the Viking landers of the mid-1970s.

        The probes will plunge into the surface of Mars at an
extremely high velocity of about 446 miles per hour (200
meters per second) to ensure maximum penetration of the
Martian terrain.  They should impact the surface within 120
miles (200 kilometers) of the main Mars '98 lander, which is
targeted for the planet's icy south polar region.

        Upon impact, the aeroshells will shatter and the
microprobes will split into a forebody and aftbody system.
The forebody, which will be lodged between one to six feet
underground, will contain the primary electronics and
instruments. The aftbody, connected to the forebody by an
electrical cable, will stay close to the surface to collect
meteorological data and deploy an antenna for relaying data
back to Earth.

        The microprobes will weigh less than 4.5 pounds (2
kilograms) each and be designed to withstand both very low
temperatures and high deceleration.  Each highly integrated
package will include a command and data system, a
telecommunications system, a power system, and primary and
secondary instruments.  Nearly all electrical and mechanical
designs will be new to space flight.

        "In addition to a team of industrial partners that
will help develop advanced technologies to be demonstrated
during the mission, we have just selected Lockheed Martin
Electro-Optical Systems as a primary industry partner to
participate in the integration and test program for the
microprobes," said Sarah Gavit, Mars microprobe flight leader
at JPL.

        Technologies proposed for demonstration on this
second New Millennium flight include a light weight, single-
stage entry aeroshell, a miniature, programmable
telecommunication subsystem, power microelectronics with
mixed digital/analog integrated circuits, an ultra low-
temperature lithium battery, a microcontroller and flexible
interconnects for system cabling.

        In-situ instrument technologies for making direct
measurements of the Martian surface will include a water and
soil sample experiment, a meteorological pressure sensor and
temperature sensors for measuring the thermal properties of
the Martian soil.

       "The Mars microprobe mission will help chart the
course for NASA's vision of space science in the 21st
century, a vision that incorporates the concept of 'network
science' through the use of multiple planetary landers," said
Kane Casani, manager of the New Millennium program. The
probes will become the first technology to be validated in
this new network approach to planetary science.

"Networks of spacecraft will address dynamic, complex
systems," Casani said. "For example, a single lander can
report on the weather at one spot on a planet, but a network
of landers is needed to characterize the planet's dynamic
climate. Similarly, a single seismometer will indicate if a
quake has occurred on a planet, but a network of seismometers
can measure the size of a planetary core.  We need multiple
spacecraft to go beyond our initial reconnaissance to
completely characterize dynamic planetary systems the way we
are able to do on Earth."

        The New Millennium program is managed by JPL for
NASA's Office of Space Science and Office of Mission to
Planet Earth, Washington, DC.  The Mars `98 lander, managed
by JPL for the Office of Space Science, is in development at
Lockheed Martin Astronautics Corp., Denver, CO, under
contract to JPL.

                           -end-