Projects: Mars Climate Sounder Team Website
Mars Climate Sounder Captures Views of Other Instruments
Data acquired March 24-25, 2006
Credit: NASA / JPL-Caltech
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Just two weeks after arriving at Mars, Mars Reconnaissance Orbiter captured
what may be the first-ever self-portrait from a planetary orbiter. The
snapshot was not taken by any of the orbiter's cameras; it came from Mars
Climate Sounder.
Before aerobraking began, a few of the instruments, including Mars Climate
Sounder and HiRISE (the high-resolution camera), were powered on to perform
some preliminary observations. The data captured by Mars Climate Sounder
included views of the orbiter's instrument deck, encompassing many of the instruments
and one of the solar panels. Although the black-and-white image above
looks like a photo, it wasn't taken in wavelengths of light visible to human
eyes. The instrument deck was in shadow when the data was captured, so
the view looks black in visible wavelengths. The brightness and darkness
of the pixels in this image represents thermal radiation -- heat -- coming off
the objects in view of Mars Climate Sounder. The images below are colorized
to help illustrate the temperature differences.
Mars Reconnaissance Orbiter instrument deck (channel B1)
Credit: NASA / JPL-Caltech
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This view was captured in a mid-infrared wavelength of 32.5 microns. At
the bottom of the view is the spacecraft instrument deck, which is below
the MCS instrument. Mars would be above the view but is not visible
here. There is a sharp and obvious boundary between the slightly
warm instrument deck and the blackness of space. The instrument deck
has a square shape, which is distorted in this angular-space view into
a cusp shape.
What are all the lumps and bumps? On the extreme left, half of the
CRISM spectrometer is visible. CRISM has an aperture that is cylindrical
in shape and projects approximately vertically from the instrument deck. Close
to the deck is a fan-shaped cooler that makes a blue bulge. The bright
green blob below that is the CRISM electronics box.
The darker blue pyramid-shaped object to the right of CRISM is one corner
of the spacecraft. An attitude thruster is mounted on the corner
and is covered by a thermal blanket.
In the center of the image is the skinny projection of the MARCI context
imaging camera.
The large shape to the right of center is composed of two separate objects. In
the foreground is the mostly blue Electra radio antenna. It is largely
blocking a view of one of the two solar panels.
At the far right is the large cylindrical body of the HiRISE camera. At
the moment that this image was taken, HiRISE was powered on. Three
small struts support HiRISE's secondary mirror. When HiRISE is in
use, these struts are heated to a specific temperature in order to make
sure that they maintain a constant and known length. Those heated
struts form the hottest pixels in this thermal image.
Mars Reconnaissance Orbiter instrument deck (channel A2)
Credit: NASA / JPL-Caltech
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This view, captured in a wavelength of 15.8 microns, appears very similar
to the 32.5-micron view, but there are a few interesting differences. First
of all, it was captured through the other "eye" of the MCS instrument. MCS
contains two telescopes mounted side-by-side, called Telescopes A and B. They
are coaligned so that when the instrument looks at distant Mars, both telescopes
capture the same fields of view. However, in this unusual image,
MCS is looking at objects so close to it that there is parallax between
views from the two eyes. The most obvious effect of parallax is that
in the 15.8-micron image from Telescope A, much more of the solar panel
is peeking out from behind the Electra antenna than is visible in the Telescope
B image.
Mars Reconnaissance Orbiter instrument deck - blink comparison
Credit: NASA / JPL-Caltech
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Another
difference is that the entire bottom of this image, corresponding to angles
immediately above the MCS instrument, is a solid color. That's because
there is a solar calibration target for the broadband visible channel of
the MCS instrument located above telescope A. Because the broadband
visible channel is located in only telescope A and not telescope B, the
calibration target was built only to cover the aperture of telescope A. The
other telescope has no such calibration target (its channels are calibrated
by pointing at the blackbody targets alone).
Parts of Mars Climate Sounder
Credit: NASA / JPL-Caltech
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