NASA Mars Picture of the Day: The MGS MOC Search for Beagle 2

Mars Global Surveyor Mars Orbiter Camera

MGS MOC Release No. MOC2-835, 31 August 2004

Beagle 2 was anticipated to land in Isidis Planitia on 25 December 2003.
Less than half an hour after scheduled touchdown, the Mars Global
Surveyor (MGS) Mars Orbiter Camera (MOC) acquired a wide angle view
of the landing site. It was hoped by the MOC team that some
evidence of the lander’s passage through the atmosphere would
be seen. That image was released on the MGS MOC web site on
31 December 2003.
Like subsequent wide angle images obtained during the landings of the
two Mars Exploration Rovers
(e.g., Spirit),
there was no visible atmospheric descent contrail or plume.

As the next several days passed without a signal from Beagle 2, the
MGS MOC team, in consultation with the Beagle 2 team, began a search
for the lander. The Beagle 2 team projected the highest probability
landing ellipse in Isidis Planitia, and that information was made
available to the MOC operations team. In other words, Beagle 2 was
expected to have landed within a very specific zone. That area
is shown below in Figure MOC2-835a.

Prior to landing, there were no MOC images of the final landing
ellipse. The final ellipse was a bit further north than originally
planned, thus all of the MOC coverage obtained before the landing
was concentrated in an area outside the final ellipse.
Thus, it would not be possible to compare a “before and
after” view of the site where Beagle 2 had landed. The first opportunity
to acquire an image of a portion of the ellipse occurred on
5 January 2004, as shown in Figure MOC2-835a and released
on 30 January 2004. The ellipse in Figure MOC2-835a is drawn over a base map
constructed from Mars Odyssey THEMIS Visible and Infrared images
that were available at the time of landing.

Subsequent MOC imaging of the Beagle 2 landing site
focused on the eastern half of the ellipse. The Beagle 2
team’s decision to request that MOC concentrate its limited
imaging opportunities on the eastern half of the ellipse
was based on knowledge of the conditions of the martian
atmosphere that came up during the period in which all
three landers–Beagle 2, Spirit, and Opportunity–reached
the planet. In December 2003, large dust storms had
altered the temperature and pressure conditions of the
atmosphere, and this ultimately resulted in the two
Mars Exploration Rovers landing downrange (east) of
the centers of their landing ellipses. Beagle 2, also,
might have landed east of the ellipse center.

Figure MOC2-835b shows the MOC narrow angle camera coverage,
acquired at full resolution of 1.5 m/pixel, obtained during
the lander search campaign in January through April 2004.
The 2 km scale bar is about 1.2 miles long.
Slightly more than 36% of the total ellipse, and 72% of the
east half of the ellipse, has been covered by MOC. Raw,
cosmetically-cleaned, and map-projected versions of each
MOC image were provided to the Beagle 2 team
for evaluation. MOC scientists at Malin Space Science Systems
also examined the images for evidence of Beagle 2, it parachute,
or other hardware.

Based on their experience with searches
for previous landed vehicles (Viking 1, Mars Pathfinder, Mars
Polar Lander, MER-A (Spirit), and MER-B (Opportunity)), and
their knowledge of the characteristics of the MOC imaging
system, only one reasonably-likely candidate for Beagle 2 was
identified. That candidate is indicated
in Figure MOC2-835b by an arrow. The candidate is a small, dark
spot located immediately west of the largest meteor impact
crater in the Beagle 2 ellipse, at 11.7°N, 269.4°W.
The dark spot suggested that perhaps Beagle 2 had crashed
at this location. However, the dark spot is about 20 meters
(~65 ft.) across, a bit larger than might be created by a crashed
lander of Beagle 2’s size.

MOC2-835b: East half of Beagle 2 landing ellipse, showing main MOC search area. Arrow indicates candidate “crash” site found by MOC. View at 12 m/pixel (5.2 MB) — View at 6 m/pixel (10.4 MB) — View at 3 m/pixel (31.4 MB) NASA/JPL/Malin Space Science Systems

The next step in the search for Beagle 2 was to acquire
an image of the dark spot with
the very highest resolution that can be obtained using
the MGS MOC system. MOC was designed to obtain images
of resolutions as high as 1.4 to 1.5 meters per pixel
(5 feet per pixel). However,
during 2003 and 2004, the MOC and MGS operations
teams have been developing and testing a technique whereby
images of 50 centimeters per pixel in the downtrack
direction (still 1.5 m/pixel crosstrack) can be acquired.
This technique, known as cPROTO (compensated Pitch and
Roll Targeted Observation), was used with terrific success
to find the
Viking 1 and Mars Pathfinder landers, and the Mars Exploration Rovers,
Spirit and
Opportunity.

Because the cPROTO technique is still new, it took two
tries before MOC hit the candidate Beagle 2 site. Figure MOC2-835c
shows a comparison of the results obtained from the normal, 1.5 m/pixel
view in which the candidate site was found (left), and the cPROTO obtained
with 50 cm/pixel resolution in April 2004 (right). With the higher
spatial resolution obtained by the cPROTO, it became clear that the
candidate Beagle 2 “crash” site was really just a small, eroded meteor
impact crater with a dark patch of sand on its northern floor.

MOC2-835c: Candidate “crash” site viewed at 1.5 m/pixel (the original MOC image of the spot) and at 0.5 m/pixel in later MOC cPROTO image. View at 50% original size (3.4 MB) — View at full size (5.2 MB) NASA/JPL/Malin Space Science Systems

The full cPROTO image of the Beagle 2 candidate site is shown in
Figure MOC2-835d. This image has been map-projected at 50 cm/pixel
scale and is 3 km (1.9 mi) wide (north is up and the dark bars
result from data loss
upon transmission). The white arrow indicates the location of the
dark candidate Beagle 2 site, which turned out to be a small, degraded
impact crater and windblown sand.

MOC2-835d: The full MOC cPROTO image acquired in April 2004 to examine the candidate “crash” site. View at 3 m/pixel (3.4 MB) — View at full size, 50 cm/pixel (36.6MB) NASA/JPL/Malin Space Science Systems

Based on the MGS MOC imaging campaign and subsequent analyses,
no incontrovertible evidence of the Beagle 2 lander was found within
the areas imaged by MOC. While the period of intense searching by
MOC has ended, the landing ellipse will remain a MOC target,
indefinitely, until either the ellipse is covered or the MGS MOC
mission ends, whichever comes first. At present, MOC is expected
to continue observing Mars into late 2006, and the MOC team
hopes, because of the science benefits anticipated, that
another mission extension will be possible beyond 2006.

All MOC narrow angle images shown here are illuminated from the
left/lower left and oriented such that north is up and east
is to the right. MOC images and text describing the search for
Beagle 2 by MGS MOC were included in the final report of the
Beagle 2 team, released on 24 August 2004. For more information
about Beagle 2 and the team’s reports, visit
http://www.beagle2.com/.

Malin Space Science Systems and the California Institute of Technology
built the MOC using spare hardware from the Mars Observer mission.
MSSS operates the camera from its facilities in San Diego, California.
The Jet Propulsion Laboratory’s Mars Surveyor Operations Project
operates the Mars Global Surveyor spacecraft with its industrial
partner, Lockheed Martin Astronautics, from facilities in Pasadena,
California and Denver, Colorado.