M.R.O. - Il radar SHARAD pronto ad entrare in azione

PASADENA, CALIF. 91109 TELEPHONE (818) 354-5011

Guy Webster 818-354-6278
Jet Propulsion Laboratory, Pasadena, Calif.

Dwayne Brown/Erica Hupp 202-358-1726/1237
NASA Headquarters, Washington

News Release: 2006-109 September 19, 2006

Ground-Piercing Radar on NASA Mars Orbiter Ready for Work

NASA’s Mars Reconnaissance Orbiter has extended the long-
armed antenna of its radar, preparing the instrument to
begin probing for underground layers of Mars.

The orbiter’s Shallow Subsurface Radar, provided by the
Italian Space Agency, will search to depths of about one
kilometer (six-tenths of a mile) to find and map layers
of ice, rock and, if present, liquid water.

The radar’s antenna had remained safely folded and tucked
away throughout the flight to Mars from Aug. 12, 2005, to
March 10, 2006, and while the orbiter used the friction
of dipping into the top of Mars’ atmosphere 426 times in
the past six months to shrink the size of its orbit.
Latches on the restraints were popped open on Sept. 16,
and the spring-loaded twin arms of the antenna unfolded
themselves. Subsequent information from the spacecraft
indicates that each arm properly extended to its 5 meter
(16.4 feet) length.

“The deployment of the antenna has succeeded. It went
exactly as planned,” said Dr. Enrico Flamini, the Italian
Space Agency’s program manager for the Shallow Subsurface
Radar. “Now the excitement builds about what the radar
will find hiding beneath the surface of Mars.”

A radar-team engineer at NASA’s Jet Propulsion Laboratory,
Pasadena, Calif., Ali Safaeinili, said, “Motion sensors
on Mars Reconnaisance Orbiter gave us good evidence that
the antenna had deployed successfully. The amount of
antenna vibrations as the arms unfolded was within the
range anticipated.”

The radar received its first radio echo from the Martian
surface during a test on Sept.18, providing a preliminary
indication that the entire instrument is working properly.
Researchers will use the instrument for more test
observations at the end of this month. Communication
with all spacecraft at Mars will be intermittent during
most of October while that planet is behind the sun from
Earth’s perspective. The two-year-long main science phase
of the Mars Reconnaissance Orbiter mission will begin in

“We will use the Shallow Radar to map buried channels, to
study the internal structure of ice caps and to see
boundaries between layers of different materials,” said
Dr. Roberto Seu of the University of Rome La Sapienza,
leader of the instrument’s science team. “The data will
provide our first detailed look just under the Martian
surface, where ices might reside that would be accessible
for future explorers.”

The radar instrument on the Mars Reconnaissance Orbiter
will complement a similar instrument that went into use
last year on the European Space Agency’s Mars Express
orbiter, the Mars Advanced Radar for Subsurface and
Ionospheric Sounding. The two instruments use different
radar frequencies. The one on Mars Reconnaissance Orbiter
can discriminate between thinner layers, but cannot
penetrate as deep underground, compared with the one on
Mars Express. Both result from Italian and American
partnership in using radar for planetary probes.

Alcatel Alenia Spazio-Italia, in Rome, is the Italian
Space Agency’s prime contractor for the instrument. Astro
Aerospace, of Carpineria, Calif., a business unit of Los
Angeles-based Northrop Grumman Corp., developed the
antenna as a subcontractor to Alcatel Alenia.

Further information about the Shallow Subsurface Radar
is online at www.sharad.org . For more detailed
information about the Mars Reconnaissance Orbiter, see
www.nasa.gov/mission_pages/MRO/main . The mission is
managed by JPL, a division of the California Institute
of Technology, Pasadena, for the NASA Science Mission
Directorate, Washington. Lockheed Martin Space Systems,
Denver, is the prime contractor and built the orbiter.