Qualche problemino per MRO

Feb. 7, 2007

Dwayne Brown
Headquarters, Washington

Guy Webster
Jet Propulsion Laboratory, Pasadena, Calif.

RELEASE: 07-24


WASHINGTON - NASA’s Mars Reconnaissance Orbiter spacecraft this month
is set to surpass the record for the most science data returned by
any Mars spacecraft. While continuing to produce data at record
levels, engineers are examining why two instruments are
intermittently not performing entirely as planned. All other
spacecraft instruments are operating well and continue to return
science data.

Since beginning its primary science phase in November 2006, the
orbiter has returned enough data to fill nearly 1,000 CD-ROMs. This
ties the record for Mars data sent back between 1997 and 2006 by
NASA’s Mars Global Surveyor mission.

In late November 2006 the spacecraft team operating the High
Resolution Imaging Science Experiment camera on Mars Reconnaissance
Orbiter noticed a significant increase in noise, such as bad pixels,
in one of its 14 camera detector pairs. Another detector, that
developed the same problem soon after launch, has worsened. Images
from the spacecraft camera last month revealed the first signs of
this problem in five other detectors.

While the current impact on image quality is small, there is concern
as to whether the problem will continue to worsen.

In-flight data show that more warming of the camera’s electronics
before taking an image reduces or eliminates the problem. The imaging
team aims to understand the root cause of the worsening over time and
to determine the best operational procedures to maximize the
long-term science benefits. The camera continues to make observations
and is returning excellent images of the Martian surface.

The second instrument concern aboard the Mars Reconnaissance Orbiter
is related to an instrument designed to routinely scan from the
surface across the atmosphere above Mars’ horizon. The Mars Climate
Sounder maps the temperature, ice clouds and dust distributions in
the atmosphere on each of nearly 13 orbits every day. In late
December, the sounder appeared to skip steps occasionally, so that
its field of view was slightly out of position. Following uplink of
new scan tables to the instrument, the position errors stopped and
the instrument operated nominally.

In mid-January, the position errors reappeared. Although still
intermittent, the errors became more frequent, so the instrument has
been temporarily stowed while the science team investigates the

The rate of data return is expected to increase over the coming months
as the relative motions of Earth and Mars in their orbits around the
sun shrink the distance between the planets. By the conclusion of its
first science phase in 2008, the mission is expected to have returned
more than 30 terabits of science data, enough to fill more than 5,000
CD-ROMs. Observations will be used to evaluate potential landing
sites for future missions and to increase our understanding of Mars
and how planets change over time.

The mission is managed by NASA’s Jet Propulsion Laboratory, Pasadena,
Calif., for NASA’s Science Mission Directorate, Washington. Lockheed
Martin Space Systems, Denver, Colo., is the prime contractor and
built the spacecraft.

Additional information about the Mars Reconnaissance Orbiter is
available on the Web at: