NASA announced today that The Johns Hopkins University Applied Physics
Laboratory (APL) in Laurel, Md., will provide a key science instrument on
the Mars Reconnaissance Orbiter, the spacecraft NASA plans to send to the
Red Planet in 2005.

Over the next two years an APL team will design and build the $17.6 million
Compact Reconnaissance Imaging Spectrometer for Mars, or CRISM, which will
search for mineral residues of past or recent water on the Martian surface.
As the orbiter flies over a given area, CRISM’s scanning mechanism allows
the instrument’s visible and infrared spectrometers to track a targeted
region on the surface and map it from different angles as the orbiter passes
overhead. CRISM uses the spectrum of reflected sunlight to determine the
mineralogy of surface materials at scales as small as 82 feet (25 meters).

“By looking at the different spectra of reflected sunlight, the instrument
will pick up the ‘fingerprints’ of different minerals,” says CRISM Principal
Investigator Dr. Scott Murchie of the Applied Physics Laboratory. “Finding
certain minerals on the surface tells you that water has been there. The
exact combination of minerals tells you about the climatic conditions at the
surface when the water flowed as liquid.” Between its targeted,
high-resolution observations, CRISM will search the planet at a reduced set
of wavelengths to find new sites of interest not previously suspected. “Many
of the oldest rocks will be battered by craters so that ancient lakes and
springs wouldn’t be obvious just from pictures. This survey capability will
help us find places for future landings that wouldn’t otherwise be

Set to launch in August 2005, the Mars Reconnaissance Orbiter is the latest
mission in NASA’s long-term Mars exploration program. The craft will analyze
the surface at new scales to follow hints of water detected in images from
the Mars Global Surveyor spacecraft, and to bridge the gap between surface
observations and measurements from orbit. The MRO high-resolution imager,
also selected by NASA at the same time as CRISM, will return the sharpest
images of the Martian surface ever taken by Mars-circling orbiters – at
resolutions high enough to spot rocks the size of beach balls. The mission
will identify ideal locations for future landers to touch down on Mars.

Though CRISM is the first APL-developed science tool on a Mars mission, the
Laboratory has built 59 spacecraft and provided 136 instruments for a
variety of Earth-orbiting and deep space satellites over the past 40 years.
APL managed NASA’s Near Earth Asteroid Rendezvous (NEAR) mission, which
included the first spacecraft to orbit and land on an asteroid. Other
APL-managed NASA missions include the Comet Nucleus Tour (CONTOUR), which
launches in July 2002 for a comprehensive study of at least two comets, and
MErcury Surface, Space ENvironment, GEochemistry and Ranging (MESSENGER), a
Mercury orbiter set to launch in 2004.

In fact, CRISM derives much of its design from the high-resolution camera
and spectral mapper on the CONTOUR spacecraft, currently under construction
at APL. “The requirements for making these kinds of observations on Mars are
similar to those for mapping the nucleus of a comet,” says Dennis Fort,
CRISM systems engineer. “The approach used on CONTOUR for tracking a comet
and acquiring high resolution spectra adapts nicely to prospecting for small
mineral deposits on the surface of Mars from orbit.” Other components of
CRISM are adapted from the similarly scannable imaging system on the
MESSENGER Mercury orbiter, also currently under development at APL.

APL provided the ultra-stable oscillator – a super-precise timekeeping
device – for Mars Global Surveyor, which has been essential to mapping
atmospheric structure and circulation patterns on Mars for the past four

For more information about APL’s space programs, visit For more information about NASA’s Mars Exploration
Program, visit