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Lander Scientific Instruments
Mars Descent Imager (MARDI)
- Images taken starting just before heatshield jettison, and continue
until landing
- Megapixel, electronically shuttered CCD will take panchromatic images
of the landing site at 1.25 mrad/pixel
- 10 1000x1000 pixel images will be taken, covering areas from 9 km
to 9 m across at resolutions of 7.5 m to 9 mm per pixel pair
MARDI includes a single camera head consisting of optics, focal plane
assembly and support electronics, and housing. Using a megapixel, electronically
shuttered CCD, MARDI provides panchromatic images of the landing site
with a resolution of 1.25 mrad/pixel. Images are taken starting just before
heatshield jettison, and continue until landing. Under nominal circumstances
approximately ten 1000 x 1000 pixel images will be acquired. Taken at
altitudes less than 8 km above the surface, these images cover areas from
9 km to 9 m across and at resolutions of 7.5 m to 9 mm per pixel pair.
MARDI is built by Malin Space Science Systems (MSSS), with Dr. Michael
Malin (MSSS) as Principal Investigator.
Light Detection and Ranging (LIDAR)
- Upward viewing lidar mounted on the Lander deck
- Provided by Space Research Institute (IKI) (Russian Academy of Science)
under sponsorship of the Russian Space Agency (RSA).
- LIDAR transmitter uses a pulsed GaAlAs laser diode
- 2 sounding modes:
- Active sounding: light pulses emitted and their return
timed to locate and characterize ice and dust hazes below 2-3
km
- Acoustic device (microphone)
The LIDAR [Light Detection and Ranging] is an upward viewing lidar mounted
on the Lander deck. It consists of a sensor assembly, an electronics assembly,
and the interconnecting cable assembly. The LIDAR is provided by the Space
Research Institute (IKI) of the Russian Academy of Science, under the
sponsorship of the Russian Space Agency (RSA). The Principal Investigator
is S. Linkin.
The LIDAR transmitter uses a pulsed GaAlAs laser diode which emits
400 nJ energy in 100 nsec pulses at a rate of 2.5 kHz and at 0.88 µm
wavelength. The LIDAR has two sounding modes. During active sounding,
light pulses are emitted and their return timed in order to locate and
characterize ice and dust hazes in the lowest few kilometers (< 2-3
km). An acoustic device [microphone] will also be included as part of
the LIDAR assembly.
Mars Microphone
Ever wonder what it sounds like on Mars? When the next lander
in NASA's program to explore the Red Planet touches down in 1999, we will
all have the chance to find out. Onboard the Mars Polar Lander will be
a small recording device, the Mars Microphone, whose job is to sample
sound while the rest of the probe studies the soil, weather, and atmospheric
dust.
The Mars Microphone is a small device, roughly 5 centimeters on a
side and one centimeter thick (2 x 2 x 0.5 inches), weighing less than
50 grams (1.8 ounces) and using a small amount of power, less than 0.1
watt during its most active times. In addition to the microphone, the
instrument contains digital electronics to acquire and store sound samples.
Because the rate at which we can acquire data will be limited, it will
take several days, maybe even a week, to retrieve one 10-second sound
clip. The device has internal memory, similar to the RAM in your home
computer, which will store sounds for transmission to Earth along with
other lander data.
The Mars Microphone is composed of commercial, off-the-shelf technology,
meaning that very few of the components were developed specifically
for this mission. Most are readily available commercially. Our sound
processor chip, for example, is also used in talking toys and educational
computers that listen and respond to spoken words. The microphone itself
is typically used in hearing aids. The entire program, including design,
construction, and testing, cost roughly $50,000, a bargain for an instrument
on a planetary probe.
Mars Volatiles and Climate Surveyor (MVACS)
MVACS is an integrated payload with four major science elements:
a Stereo Surface Imager, a Robotic Arm with Camera, a Meteorological package
of pressure, temperature, wind, and water vapor sensors, and a Thermal
and Evolved Gas Analyzer. Dr. David Paige (UCLA) is tee Principal Investigator
for the MVACS.
Stereo Surface Imager (SSI)
- Mast-mounted stereo color imager, clone of Mars Pathfinder IMP
- Multispectral capability (0.4 - 1.1 microns)
- Dual optics focusing on single CCD
- Provides panoramas of site and imaging support for other payload
elements, especially the Robotic Arm and TEGA
- Images magnetic targets on deck
- Magnetic characterization of surface material
- Narrow-band imaging of Sun
- Line of sight optical depths of aerosols
- Slant column water vapor abundances
The mast-mounted SSI provides panoramas of the Lander site, characterizes
the general environment at the landing site, and provides imaging support
for other payload elements, especially operations of the RA and TEGA,
and for the spacecraft, as needed. The SSI is essentially a clone of the
Mars Pathfinder IMP; it is a multi-spectral imager accessing several wavelengths
between 0.4 and 1.1 microns. This multi-spectral capability, together
with onboard calibration targets, provides true color images. SSI also
images magnetic targets on the Lander deck to characterize the magnetic
properties of surface material. Narrow-band imaging of the sun provides
line-of-sight optical depths of atmospheric aerosols and (slant column)
water vapor abundances. Stereo imaging is provided by the dual optical
lens systems focusing onto a single CCD.
Robotic Arm (RA) and Robotic Arm Camera (RAC)
- 2-meter arm with articulated end member, camera, and temperature
probe
- Digs trenches, to acquire samples of surface and subsurface materials,
and support operations of the RAC
- RAC images surface and subsurface to reveal fine-scale layering
if present and characterize fine-scale texture of the samples and
trench sides
A two-meter RA with an articulated end member is used to dig trenches
at the site, to acquire samples of surface and subsurface materials, and
to support operations of an attached RA Camera. The RAC will image the
surface and subsurface at close range to reveal fine-scale layering if
present and to characterize the fine-scale texture of the samples and
trench sides. The light-weight RA also supports a probe for measuring
surface and subsurface temperatures.
Meteorological Package (MET)
- Mounted on 1.2-m mast: wind (speed and direction) sensor, temperature
sensors, and Tunable Diode Lasers (TDL) which measure water vapor
amounts and specific isotopes of water and carbon dioxide
- Secondary mast (0.9 m) is attached to the main MET mast: wind speed
& 2 temperature sensors near the surface saltation layer
- Pressure sensors are mounted within the spacecraft
- On the surface, MET sensors are read at periodic intervals, as power
permits
A two-meter RA with an articulated end member is used to dig trenches
at the site, to acquire samples of surface and subsurface materials, and
to support operations of an attached RA Camera. The RAC will image the
surface and subsurface at close range to reveal fine-scale layering if
present and to characterize the fine-scale texture of the samples and
trench sides. The light-weight RA also supports a probe for measuring
surface and subsurface temperatures.
Thermal and Evolved Gas Analyzer (TEGA)
- Uses differential scanning calorimetry (DSC) combined with gas-specific
sensors to determine the concentrations of ices, adsorbed volatiles
and volatile-bearing minerals in surface and subsurface samples acquired
and imaged by the Arm.
- RA deposits the sample in a receptacle, which is then mated with
a cover to form the oven; Evolved gases are wafted to sensors which
quantify the rate of discharge of oxygen, carbon dioxide and water
vapor. Once used, the ovens cannot be used again. Eight surface [soil]
samples can be analyzed.
TEGA uses differential scanning calorimetry (DSC) combined with gas-specific
sensors to determine the concentrations of ices, adsorbed volatiles and
volatile-bearing minerals in surface and subsurface samples acquired and
imaged by the Robotic Arm (RA). The RA deposits the sample on a grated
screen over a chute which fills the sample receptacle. This receptacle
is then mated with a cover to form the oven in which the sample is heated;
a paired (empty) oven provides a calibration for the heating run. Evolved
gases are wafted to sensors which quantify the rate of discharge of oxygen,
carbon dioxide and water vapor. Once used, the ovens cannot be used again.
TEGA is designed to receive eight surface (soil) samples during the Lander
mission.
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