Transcript Mars Pathfinder Mission

Mars Pathfinder Mission
Breakthrough on the Surface of Mars
A Few Facts On The Mission…
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Launch: 4 December 1996 UT 06:58
Arrival: 4 July 1997 UT 16:57
Final Transmission: 27 September 1997 PDT 03:23
Launch Vehicle: Delta 2
Mass: 264 kg (Lander), 10.5 kg (Rover)
Dimensions (Rover): 0.28 m high X 0.63 m length X 0.48 m wide,
0.13 m ground clearance
• Power System: Solar panels
• Total Cost: $265 million (including launch and operations)
A Few More Facts On The Mission…
• Lander was operational for 30 days (3 times its expected life); Rover
was operational for 83 days (12 times its expected life).
• Over course of mission, relayed 2.3 GB of data, including 16 500
images from the Lander’s camera, 550 images from the Rover camera,
16 chemical analyses of rocks and soils, and 8.5 million measurements
of atmospheric pressure, temperature, and wind.
Mission Objectives
• Mars Pathfinder was the second launch in the Discovery Program, a
NASA initiative for planetary missions with a maximum 3 year
development cycle and a cost cap of $150 million for development
(1/15th the cost of the Viking missions).
• To demonstrate NASA’s commitment to low-cost planetary exploration
on the surface.
• To demonstrate the mobility and usefulness of a microrover on the
surface.
Landing the Pathfinder
• Landing zone chosen according to images taken during the Viking
mission in the mid-1970s.
• Pathfinder landed downstream from the mouth of Ares Vallis, a giant
catastrophic outflow channel.
• This landing zone was chosen, as it was believed the examination of
the different surface materials would allow a first-hand scientific
investigation of early differentiation and evolution of the crust, the
development of weathering products, and a sense for early
environment and conditions that once existed on Mars.
Landing the Pathfinder
Scientific Objectives
• To land a single vehicle with a microrover (Sojourner) and several
instruments on Mars in 1997.
• The mobility of the Sojourner was to allow “ground truthing” on an
area of over 100 m2 on Mars.
• To investigate the surface with 3 additional instruments:
• IMP – Imager for Mars Pathfinder
• APXS – Alpha-Proton X-ray Spectrometer
• ASI/MET – Atmospheric Structure Instrument/Meteorology Package
Instruments Aboard Sojourner
Instruments Aboard Sojourner
IMP – Imager for Mars Pathfinder
• Reveals Martian geological processes and surface-atmosphere
interactions similar to what was observed at the Viking landing sites in
the mid-1970s.
• Makes observations of general landscape, surface slopes and
distribution of rocks obtained by panoramic stereo images at various
times during the day.
• Makes regular sky and solar spectral observations, and monitors
windborne particle size, particle shape, distribution with altitude, and
abundance of water in vapour.
Instruments Aboard Sojourner
APXS – Alpha-Proton X-ray Spectrometer
• Determines the dominant elements that make up rocks and other
surface materials at the landing site.
• Gives an understanding of the materials that may lead to the
determination of the composition of Martian crust, as well as
secondary weathering processes (such as different types of soils).
• Investigations provide calibration points for orbital remote sensing
observations such as the Mars Global Surveyor.
• Along with the magnetic targets distributed at various points around
the craft, it is possible that the mineral composition of the rocks can be
inferred.
APXS
Instruments Aboard Sojourner
ASI/MET – Atmospheric Structure
Instrument/Meteorology
• Determines the temperature and density of the
atmosphere during Entry, Descent and Landing
(EDL).
• 3-axis accelerometers are used to measure
atmospheric pressure during EDL.
• Once on the surface, meteorological
measurements (pressure, temperature, wind
speeds, atmospheric opacity) are measured on a
daily basis.
• Wind directions and speeds are measured by a
wind sensor mounted atop a stable mast.
Discoveries of the Pathfinder Mission
Major Discoveries
• The immediate vicinity of the landing appears to have been dry and
unchanged for the past 2 billion years.
• Chemical analysis of rocks by the APXS suggest that all rocks studied
by the Rover resemble andesite, a volcanic rock with high silica
content, covered in a fine layer of dust.
• Martian dust includes magnetic, composite particles, with a mean size
of one micron.
• Dust is confirmed as the dominant absorber of solar radiation in Mars'
atmosphere, which has important consequences for the transport of
energy in the atmosphere and its circulation.
Discoveries of the Pathfinder Mission
• Evidence of wind abrasion of rocks and dune-shaped deposits was
found, indicating the presence of sand.
• Rock size distribution was consistent with a flood-related deposit.
• It was determined that clouds, not fog, obscured the view of Martian
mornings from space.
• The possible identification of rounded pebbles and cobbles on the
ground, and sockets and pebbles in some rocks, suggests
conglomerates that formed in running water, during a warmer past in
which liquid water was stable.
Discoveries of the Pathfinder Mission
Discoveries of the Pathfinder Mission
Conclusion
“Done quickly and within a very limited budget, Pathfinder
set a standard of 21st century space exploration.”
Dr. David Baltimore, president of the California
Institute of Technology, which manages JPL for NASA
References
http://mars.jpl.nasa.gov/MPF/index0.html
 Mars Pathfinder Mission Home Page
http://nssdc.gsfc.nasa.gov/planetary/mesur.html
 Mars Pathfinder Project Information
http://mars.jpl.nasa.gov/MPF/science/mineralogy.html
 Mars Pathfinder – Science Results – Mineralogy and Geochemistry
http://mars.sgi.com/ops/apx-res2.html
 Mars Pathfinder – APXS Preliminary Results