Mars Exploration Rovers and Two Year Highlights

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Mars Exploration Rovers and Two Year Highlights
http//mars.jpl.nasa.gov/mer/gallery/artwork/rover
2browse.html
Assembly, Test and Launch
Rover
Two Earth Year Highlights of the Rovers Spirit

Opportunity
Reference Information
http//marsrovers.jpl.nasa.gov/gallery/press/oppor
tunity/20040506a/01-SS-01-Endurance-B101R1_br2.jpg
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MER and Mars Pathfinder Rovers at JPL
Spirit and Opportunity during assembly and test
at the Jet Propulsion Laboratory shown with the
Mars Pathfinder engineering model rover (first to
operate on Mars in July 1997).
Mars Pathfinder Sojourner Engineering Rover Model
Opportunity
Spirit
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MER-A Spacecraft/Spirit Rover Stack-up
MER-A spacecraft atop the Delta II launch vehicle
at Space Launch Complex 17-A, Cape Canaveral, FL.
Payload Fairing Half
MER-A Spacecraft with Spirit Rover in Aeroshell
Stage III
Stage II
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MER-A/Spirit Rover Launch
MER-A spacecraft launched by the Delta II 7925 at
Pad 17-A, Cape Canaveral, FL on June 10, 2003.
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MER-B/Opportunity Rover Launch
MER-B spacecraft launched by the Delta II 7925H
at Pad 17-B, Cape Canaveral, FL on July 7, 2003.
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Mars Exploration Rover
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First Look from Spirit on Mars
January 3, 2004 - Spirit lands on Mars
January 4, 2004 - This mosaic image taken by the
navigation camera on Spirit shows a panoramic
view of the rover on the surface of Mars in Gusev
Crater. The crater is about 93 miles in diameter.
A surface depression nicknamed Sleepy Hollow
can be seen to the left of center. It is an
impact crater 30 feet across and located about 40
feet north of Spirit. The airbags, shown on the
far right and left, failed to fully deflate
postponing Spirits egress off the landing craft.
The rover turns on the lander and drives down one
of the other lander ramps onto the Martian
surface on January 15.
http//marsrovers.jpl.nasa.gov/gallery/press/spiri
t/20040104a/PIA04980.jpg
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Spirit Observes Bonneville Crater and Columbia
Hills
March 12 and 13, 2004 - This mosaic is an
approximate true color image from Spirits
panoramic camera showing Bonneville Crater and
the rover's next destination named the Columbia
Hills, seen in the upper right. The crater is
about 650 feet in diameter and about 90 feet
deep. After two months of travel to Bonneville,
the impact crater was a big disappointment. There
are no layered rocks, it is shallow, filled with
sand and dust, the walls are lined with the same
shattered basalt seen previously in Gusev Crater
and no evidence of sediment below the basalt.
http//marsrovers.jpl.nasa.gov/gallery/press/spiri
t/20040318a/07-JG-01-pan-A074R1_br2.jpg
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Spirit Observes Earth
NASA/JPL-Caltech/Cornell/TexasAM
March 13, 2004 - This is the first image ever
taken of Earth from the surface of a planet
beyond the Moon. Spirit took the image one hour
before sunrise on the 63rd Martian day of its
mission. The image is a mosaic of images taken by
the rover's navigation camera showing a broad
view of the sky, and an image taken by the
rover's panoramic camera of Earth.
http//www.space.com/bestimg/index.php?guid41dd96
ca88256catrover
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Spirit Finds First Evidence of Water at Gusev
http//www-b.jpl.nasa.gov/images/mer/2004-06-15/04
-LS-01-Pot-med.jpg
June 13, 2004 - This false-color image taken by
the Spirit panoramic camera shows the rock dubbed
Pot of Gold (upper center), located near the
base of the Columbia Hills in Gusev Crater. The
rock is about the size of a softball. The
insides of the rocks appear to have been eroded,
while their outer rinds remain in tact. These
outer rinds are reminiscent of those found on
rocks at Meridiani Planum's Eagle Crater by
Opportunity.
June 25, 2004 - This 1.2 inches by 1.2 inches
close-up image taken by Spirit highlights the
nodular nuggets that cover the rock Pot of
Gold. These features appear to stand on the end
of stalk-like projections. Data from the rover's
scientific instruments has shown the Pot of
Gold contains the mineral hematite. Hematite,
found on Earth, can be formed in three different
ways in standing water in small amounts of hot
fluids (hydrothermal processes) and in volcanic
rock.
http//marsrovers.jpl.nasa.gov/gallery/press/spiri
t/20040625a/03-SS-03-MI3-A170R1_br.jpg
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Spirit Perched Above Gusev Crater
Gusev Crater Rim
August 5, 2004 - This approximate true-color
image taken by Spirit shows a rock outcrop dubbed
Longhorn, and behind it, the sweeping plains of
Gusev Crater. On the horizon, the rim of Gusev
Crater is clearly visible. The view is to the
south of the rover. The Longhorn outcrop measures
about 18 feet wide and 5 feet high.
http//marsrovers.jpl.nasa.gov/gallery/press/spiri
t/20040818a/01-SSS-01-Mosaic-A223R1.jpg
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Spirit Finds Evidence Water Flowed Through Rock
August 13, 2004 - This approximate true-color
image taken by the Spirit panoramic camera shows
the rock outcrop dubbed Clovis about 30 feet
above the plains of Gusev Crater. The rock was
softer than other rocks studied so far at Gusev.
The rover easily ground a hole into Clovis with
its rock abrasion tool. Analysis of the
interior of the hole with the rover's scientific
instruments found higher concentrations of
sulfur, bromine and chlorine compared to basaltic
(volcanic) rocks at Gusev. This might indicate
that Clovis was chemically altered, and that
fluids once flowed through the rock depositing
these elements. This suggests that water may once
have been active at Gusev.
http//marsrovers.jpl.nasa.gov/gallery/press/spiri
t/20040818a/03-DM-02-Clovis2-A223R1.jpg
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Spirit Views Husband Hill Summit Destination
February 27 to March 2, 2005 Spirits panoramic
camera acquired this view from a position known
as Larry's Lookout along the drive up Husband
Hill. The summit of Husband Hill is the far peak
near the center, and it is about 656 feet from
the rover and about 148 feet higher in elevation.
The bright rocky outcrop near the center of the
panorama is part of the Cumberland Ridge.
Beyond to the left is the Tennessee Valley.
Spirit's tracks leading back from the West
Spur region can be seen on the right side of the
panorama. The region just beyond the area where
the tracks made their zig-zag is the area known
as Paso Robles, where Spirit discovered rock
and soil deposits with very high sulfur
abundances. After obtaining this mosaic, Spirit
drove around the Cumberland Ridge rocks and drove
up the flank of Husband Hill heading toward its
summit.
http//marsrovers.jpl.nasa.gov/gallery/press/spiri
t/20050429a/Spirit_Lookout_L256t-A413R1_br2.jpg
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Spirit Reaches the Summit of Husband Hill
August 23, 2005 - This image was taken by Spirit
just as the rover completed its climb up Husband
Hill inside Gusev Crater. The summit is about
the height of the Statue of Liberty (305 feet).
It appears to be a windswept plateau of scattered
rocks, little sand dunes and small exposures of
outcrop. The view is looking toward the north,
down into the drifts and outcrops of the
Tennessee Valley, a region that Spirit was not
able to reach during its climb to the top of the
hill. The approximate true-color view consists of
images obtained by the rover's panoramic camera.
http//marsrovers.jpl.nasa.gov/gallery/press/spiri
t/20050901a/Sol582A_P2299_L456-A590R1_br2.jpg
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Spirit Investigates Husband Hill Summit
August 24 to 27, 2005 - The image is an
approximate true-color rendering. The panoramic
camera on Spirit took the hundreds of images that
combined into this view from the Husband Hill
Summit. The panorama provided the first view
of the Inner Basin region (center of the
image), including the feature Home Plate, its
next destination. After investigating the summit
area, Spirit drove downhill to get to the Inner
Basin region. Spirit arrived at the summit from
the west, along the direction of the rover tracks
seen in the middle right. The peaks of McCool
Hill and Ramon Hill can be seen on the horizon
near the center of the panorama. Spirit spent
more than a month exploring the summit region,
measuring the chemistry and mineralogy of soils
and rocky outcrops at the peak of Husband Hill
for comparison with similar measurements obtained
during the ascent.
http//marsrovers.jpl.nasa.gov/gallery/press/spiri
t/20051205a/Summit_360_L2456atc-A586R1_br2.jpg
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Spirit Views Rippled Sand Deposits
December 30, 2005 and January 1, 2006 - Spirit
welcomed the beginning of 2006 by taking this
panorama of intricately rippled sand deposits in
Gusev Crater. This is an approximate true-color
rendering of the El Dorado ripple field. The
view consists of images acquired by the Spirit
panoramic camera. The seams between individual
frames in the sky portion of the mosaic have been
eliminated to better simulate the vista a person
standing on Mars would see. Spirit spent several
days acquiring images, spectral data, and
compositional and mineralogical information about
these large sand deposits before continuing
downhill toward Home Plate.
http//marsrovers.jpl.nasa.gov/gallery/press/spiri
t/20060104a/Sol708A_El_Dorado_L257atc-A712R1_br2.j
pg
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Opportunity Captures Eagle Crater Panorama
January 24, 2004 - Opportunity lands halfway
around Mars from Spirit
April 14, 2004 - Opportunity surveys the dusty
plain of Meridiani. This image is an approximate
true-color panorama mosaic showing Eagle Crater
and some of the surrounding plains of Meridiani
Planum. This panorama depicts a story of
exploration including the rover's landing craft,
a thorough examination of the outcrop, a study of
the soils at the near-side of the lander, and a
successful exit from Eagle Crater. The impact
crater is about 72 feet in diameter and about 6
feet deep.
http//marsrovers.jpl.nasa.gov/gallery/press/oppor
tunity/20040414a/03-JS-01-LionKingPan-B079R1.jpg
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Opportunity Finds Evidence of Martian Water
http//marsrovers.jpl.nasa.gov/gallery/press/oppor
tunity/20040325a/_xpe_pubeng_approved_032304_color
_berry_bowl-B060R1.jpg
March 8, 2004 - The first outcrop rock
Opportunity examined with the microscopic imager
was finely-layered, buff-colored and in the
process of being eroded by windblown sand.
Embedded and on top of the rock, like
blueberries in a muffin, were small spherical
grains about 0.06 inches in size. The image shows
the gray spheres that have weathered out of the
rock and are resting in the darker soil. Through
intense investigations with the spectrometers,
scientists determined the blueberries are rich in
the mineral hematite. On Earth, hematite often
forms in the presence of liquid water. These
blueberries helped scientists determine that the
rocks at Eagle Crater had been soaked in water.
March 26, 2004 - This image from Opportunity's
panoramic camera is an approximate true-color
rendering of the rock called the Berry Bowl in
the Eagle Crater outcrop. The study of this
blueberry-strewn area and the identification of
hematite as the major iron-bearing element within
these sphere-like grains helped scientists
confirm their hypothesis that the hematite in
these Martian spherules was deposited in water.
http//marsrovers.jpl.nasa.gov/gallery/all/1/m/014
/1M129426904EFF0300P2932M1M1.JPG
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Opportunity Finds More Evidence of Martian Water
March, 2004 - This image taken by the Opportunity
panoramic camera shows the rock called El
Capitan, just right of center, in the upper
portion of the outcrop in Eagle Crater. El
Capitan was a significant find because it
provided clues to lead scientists to believe the
entire outcrop in Eagle Crater was once covered
in water. This image shows fine, parallel
lamination in the upper area of the rock, that
also contains scattered sphere-shaped objects
ranging from 0.04 to 0.24 inches in size. There
are also more abundant, scattered vugs, or small
cavities, that are shaped like discs. These are
about 0.4 inches long. The rover's Miniature
Thermal Emission Spectrometer uses infrared
detectors to determine the mineral composition of
rocks and soil. The spectrometer showed that El
Capitan contains a considerable amount of
sulfate. The Mössbauer Spectrometer identified
the mineral jarosite, which contains water in the
form of hydroxyl.
http//nssdc.gsfc.nasa.gov/planetary/image/merb_pa
n_elcapitan.jpg
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Opportunity Finds Evidence of a Martian Sea
March 23, 2004 - A magnified view of the rock
Upper Dells provides evidence that Opportunity
sits on the shoreline of what was once a salty
sea on Mars. Rippled patterns in the rocks at
Meridiani Planum suggest the land was once a salt
flat, sometimes covered by shallow water and
sometimes dry. Telltale patterns called
crossbedding and festooning, in which some layers
within a rock lie at angles to the main layers,
led scientists to the conclusion that the rippled
shapes formed under a current of water and not
wind.
http//www.nasa.gov/images/content/57144main_MM_im
age_feature_149_jwfull.jpg
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Opportunitys First Look at Endurance Crater
May 6, 2004 - This approximate true-color mosaic
taken by the Opportunity panoramic camera shows
the impact crater Endurance. The crater is
about 430 feet in diameter and more than 66 feet
deep. Scientists were eager to explore Endurance
for clues to Mar's geological history. The
crater's exposed walls provided a window to what
lies beneath the surface and what geologic
processes occurred in the past. The challenge was
getting to the scientific targets most of the
crater's rocks are embedded in vertical cliffs.
The rover spent six months studying Endurance
including descending into the crater and
successfully climbing out.
http//marsrovers.jpl.nasa.gov/gallery/press/oppor
tunity/20040506a/01-SS-01-Endurance-B101R1_br2.jpg
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Opportunity Views RAT Hole Trail
July 19, 2004 - This view from the rovers
panoramic camera is a false-color composite
rendering of the first seven holes that the Rock
Abrasion Tool (RAT) drilled on the inner slope of
Endurance Crater. The rover was about 39 feet
down into the crater when it acquired the images
combined into this mosaic. The view is looking
back toward the rim of the crater, with the
rover's tracks visible. The tailings around the
1.8 inch diameter holes drilled by the RAT show
evidence of fine-grained red hematite similar to
what was observed months earlier in Eagle
Crater outcrop holes. Viewers find it far
easier to see the seven holes in this exaggerated
color image than in true color the same is true
for scientists who are studying the holes on
Earth. Starting from the uppermost pictured
(closest to the crater rim) to the lowest, the
rock abrasion tool hole targets are called
Tennessee, Cobblehill, Virginia, London,
Grindstone, Kettlestone, and
Drammensfjorden.
http//photojournal.jpl.nasa.gov/jpeg/PIA06727.jpg
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Opportunity Views Burns Cliff in Endurance Crater
November 13 to 20, 2004 - Opportunity views
Burns Cliff after driving to the base of this
southeastern portion of the inner wall of
Endurance Crater. The wide-angle view makes the
cliff walls appear to bulge out toward the
camera. In reality the walls form a gently
curving, continuous surface. Scientists
analyzed data from stacked sedimentary rock
layers 23 feet thick that were exposed inside
Endurance Crater, identifying three divisions
within the stack. The lowest, oldest portion had
the signature of dry sand dunes. The middle
portion had an environment of windblown sheets of
sand with all the particles produced in part by
previous evaporation of liquid water. The upper
portion corresponded to layers Opportunity had
found inside a smaller crater near its landing
site. Scientists found that the materials in all
three divisions were wet both before and after
the layers were deposited by either wind or
water.
http//marsrovers.jpl.nasa.gov/gallery/press/oppor
tunity/20041213a/Burns_Cliff_L257T-B313R1_br2.jpg
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Opportunity Investigates its Heatshield Impact
Site
December 28, 2004 - This mosaic was acquired
shortly after Opportunity arrived at the site
where its heatshield hit the ground south of
Endurance Crater on January 24, 2004. The
heatshield was part of the aeroshell supplied by
Lockheed Martin in Denver, CO. The mosaic of
images taken by the panoramic camera are
approximate true-color. On the left, the main
heatshield piece is inverted and reveals its
metallic insulation layer, glinting in the
sunlight. The main piece stands about 3.3 feet
high and lies about 43 feet from the rover. The
other large, flat piece of debris near the center
of the image is about 46 feet away. The circular
feature on the right side of the image is the
crater made by the heatshield's impact. It is
about 9.2 feet in diameter but only 2 to 4 inches
deep. The crater is about 20 feet from
Opportunity in this view. Smaller fragments and
debris can be seen all around the impact site.
http//marsrovers.jpl.nasa.gov/gallery/press/oppor
tunity/20050203a/Sol330B_HeatShield_L257-B367R1_br
2.jpg
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Opportunity Stuck at Meridiani in Sand Dune
May 6 to May 14, 2005 - This panoramic image was
acquired by Opportunity on the plains of
Meridiani about 1.2 miles south of Endurance
Crater. The rover was stuck in the dune's deep
fine sand for more than a month at a place known
informally as Purgatory Dune. Opportunity's
tracks leading back to the north (center of the
panorama) are a reminder of the rover's long trek
from Endurance Crater. The deep ruts dug by
Opportunitys wheels as it became stuck in the
sand appear in the foreground. The crest and
trough of the last ripple the rover crossed
before getting stuck is visible in the center.
These wind-formed sand features are about 4 to 6
inches tall. The crest of the actual ripple where
the rover got stuck can be seen just to the right
of center. The tracks and a few other places on
and near ripple crests are dustier than the
undisturbed or normal plains soils in
Meridiani. Since the time these ruts were made,
some of the dust has been blown away by the wind,
reaffirming the dynamic nature of the Martian
environment, even in this barren, ocean-like
desert of sand.
http//marsrovers.jpl.nasa.gov/gallery/press/oppor
tunity/20050728a/Opp_Rub_al_Khali_L256atc-B464R1_b
r2.jpg
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Opportunity on the Rim of Erebus
Nov. 23 to Dec. 5, 2005 - This is the Erebus
Rim panorama, acquired by the Opportunity
panoramic camera while exploring sand dunes and
outcrop rocks in Meridiani Planum. Since the time
this panorama was acquired, engineers diagnosed
and tested Opportunity's robotic arm, and the
panorama has been expanded to include more images
of this terrain. The panorama is an approximate
true-color rendering, and the largest acquired by
either rover during the mission. This image
provides the highest resolution view yet of the
finely-layered outcrop rocks, wind ripples, and
small cobbles and grains along the rim of the 984
feet wide but shallow Erebus crater. Once the
arm diagnostics and testing were completed,
Opportunity started to explore other layered
outcrop rocks at Erebus and eventually continued
southward toward the large crater known as
Victoria.
http//marsrovers.jpl.nasa.gov/gallery/press/oppor
tunity/20060104a/Erebus_360_L257atc-B652R1_br2.jpg
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Reference Information
End
Images Courtesy of NASA/JPL-Caltech, Cornell
University and noted Text Roving Mars, Steven
W. Squyres, Hyperion, New York, NY,
2005 http//mars.jpl.nasa.gov/ http//marsrovers.j
pl.nasa.gov/home/index.html http//en.wikipedia.or
g/wiki/Mars_Exploration_Rover_Mission http//www.s
pace.com/bestimg/ http//www-b.jpl.nasa.gov/ http
//nssdc.gsfc.nasa.gov/planetary/ http//www.nasa.g
ov/ http//photojournal.jpl.nasa.gov/ http//www.s
paceflightnow.com/delta/d307/040728slc17.html

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MER-A Stack-up

• Boeing Delta II was selected for the MER
  missions because it had the right liftoff
  capability for the weight requirements and it is
  extremely reliable.
• MER-A with the Spirit rover used a standard
  Delta II 7925.
• MER-B with the Opportunity rover used a Delta II
  7925H (H for Heavy) because it needed more
  energy since Earth was further from Mars when it
  was launched.
• Delta II family of launch vehicles had been in
  service for over 10 years and had successfully
  launched 90 projects including the last five NASA
  missions to Mars
• Mars Global Surveyor in 1996
• Mars Pathfinder in 1996
• Mars Climate Orbiter in 1998
• Mars Polar Lander in 1999
• Mars Odyssey in 2001
• Launch Vehicle elements
• Stage I - fuel and oxygen tanks that feed an
  engine for ascent.
• Solid Rocket Motors - six strap-on, solid-fuel
  boosters are ignited at liftoff to increase
  thrust and three boosters are used after a minute
  into the flight. MER-B was launched using a Delta
  II 7925H with larger solid rocket motors than the
  MER-A.
• Payload Fairing - thin metal shroud or nose cone
  to protect the spacecraft during the ascent
  through Earth's atmosphere.
• Stage II - fuel and oxidizer and the vehicle's
  brains fire twice, once to insert the
  vehicle-spacecraft stack into low Earth orbit and
  then again to orient the third stage prior to it
  firing.
• Stage III - solid rocket motor provides the
  majority of the velocity change needed to leave
  Earth orbit and inject the spacecraft on a
  trajectory to Mars connected to the spacecraft
  until done firing, then separates.

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MER-A Stack-up (Continued)

• Launch Vehicle Complex 17 (SLC-17)
• MER spacecrafts launched from SLC-17 (pronounced
  slick) pads A and B at Cape Canaveral Air Force
  Station, FL.
• Initial construction of SLC-17 began in April
  1956 and supported its first launch in January
  1957.
• SLC-17 was modified to support the first Delta
  II launch on February 14, 1989.
• MER spacecraft is separate from the launch
  vehicle. It is the protective spaceship that
  enables the precise cargo (the rover) to travel
  between Earth and Mars once the launch vehicle
  has projected it outside of Earths atmosphere
  and gravity pull.
• Spacecraft includes the mechanical units that
  safely carry and maneuver the rover as it enters
  the Martian atmosphere and lands on Mars.
• Once on the surface, it lowers a ramp to let the
  rover drive off.
• The MER spacecraft consists of
• Cruise Stage - configuration for travel between
  Earth Mars.
• Entry, Descent, Landing System - configuration
  for entry into the Martian atmosphere. Includes
  the aeroshell (the heatshield and backshell), the
  parachute, the airbags, and a lander structure.
• Rover - six wheeled vehicle, the size of a golf
  cart, with science instruments for discoveries on
  the Martian surface.

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MER Rover

• MER spacecraft surface operations
• After the MER spacecraft entered and descended
  through the Martian atmosphere, the
  airbag-protected lander settled onto the surface
  and opened.
• The rover drove off the landing craft.
• Images were taken to give scientists information
  to select promising geological targets.
• Primary rover science instruments
• Panoramic Camera (Pancam) - determines the
  mineralogy, texture, and structure of the local
  terrain.
• Miniature Thermal Emission Spectrometer
  (Mini-TES) - identifies promising rocks and soils
  for closer examination and for determining the
  processes that formed Martian rocks. The
  instrument will also look skyward to provide
  temperature profiles of the Martian atmosphere.
• Alpha Particle X-Ray Spectrometer (APXS) - used
  for close-up analysis of the abundances of
  elements that make up rocks and soils.
• Mössbauer Spectrometer (MB) - used for close-up
  investigations of the mineralogy of iron-bearing
  rocks and soils.
• Microscopic Imager (MI) - obtains close-up,
  high-resolution images of rocks and soils.
• Rock Abrasion Tool (RAT) - removes dusty and
  weathered rock surfaces and exposes fresh
  material for examination by instruments onboard.
• Magnets - collects magnetic dust particles. The
  MB and the AXPS analyze the particles collected
  and help determine the ratio of magnetic
  particles to non-magnetic particles. They also
  analyze the composition of magnetic minerals in
  airborne dust and rocks that have been ground by
  the RAT.
• Instrument Deployment Device (IDD) - robotic arm
  with the APXS, MB, MI and RAT located on the end.

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Spirit Two Earth Year Timeline

• June 10, 2003 - MER-A with Spirit launched from
  Cape Canaveral, FL.
• January 3, 2004 - Spirit lands in Gusev Crater.
• The landing site is located at a possible former
  lake in a giant impact crater.
• In the week following Spirit's landing, NASA's
  website recorded 1.7 billion hits and 34.6
  terabytes of data transferred eclipsing records
  set by previous NASA missions.
• January 21, 2004 - Deep Space Network loses
  contact with Spirit.
• Spirit was unable to perform science operations
  for 10 days while engineers updated its software
  and ran tests. The problem was corrected by
  reformatting Spirit's flash memory and upgrading
  the software to avoid memory overload. Spirit
  returned to full scientific operations by
  February 5.
• March 5, 2004 - NASA announced Spirit had found
  hints of water history on Mars in a rock dubbed
  Humphrey.
• March 11, 2004 - Spirit reaches Bonneville
  crater after a 400 yard journey.
• September 22, 2004 - NASA announced Spirit would
  attempt to climb to the top of the Columbia
  Hills.
• Columbia Hills are older than the plains and may
  provide better insight into the past environment
  of Gustev Crater.
• December 13, 2004 - Scientists identified a
  water-signature mineral called goethite in
  bedrock that Spirit examined in the Columbia
  Hills.
• One of the mission's surest indicators yet for a
  wet history on Spirit's side of Mars.
• December 20, 2004 Spirit logs 2.5 miles on
  Mars.

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Spirit Two Earth Year Timeline (Continued)

• January 3, 2005 - Spirit celebrates 1 Earth year
  on Mars.
• March 15, 2005 - High winds remove dust from
  Spirits solar panels.
• Solar panels improved performance causes the
  rovers power supply to double.
• April 6, 2005 - NASA announces Spirit will climb
  a rocky slope toward the top of Husband Hill in
  the Columbia Hills.
• June 11, 2005 - Spirit arrives at the base of
  Columbia Hills after 2 month drive.
• August 21, 2005 - Spirit reaches the summit of
  Husband Hill after a drive of 3 miles from
  landing site.
• October 16, 2005 - Spirit starts descent from
  Husband Hill Summit to Home Plate.
• November 20, 2005 - Spirit marks one Martian
  year (687 Earth days) on Mars.
• Spirit has returned over 70,000 images and
  traveled over three miles.
• Scientists have studied the composition and
  texture of six different rock types encountered
  by Spirit. The rocks indicate Spirit is in an
  area that was once a hot, violent place with
  volcanic explosions and impacts.
• January 3, 2006 - Spirit celebrates 2 Earth
  years on Mars.

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Opportunity Two Earth Year Timeline

• July 7, 2003 - MER-B with Opportunity launched
  from Cape Canaveral, FL.
• January 25, 2004 - Opportunity landed in Eagle
  Crater at Meridiani Planum.
• Meridiani Planum, located on the opposite side
  of Mars from Spirit, is where mineral deposits
  (hematite) suggest Mars had a wet past.
• March 23, 2004 - NASA news conference announced
  major discoveries in the search for hints of
  past liquid water on the Martian surface.
• A delegation of the MER science team showed
  pictures and data revealing a stratification
  pattern and cross bedding within the rocks in the
  outcrop inside Eagle Crater suggesting a history
  of flowing water in the region. The irregular
  distribution of chlorine and bromine also
  suggests the rover sat in a place that once had
  been the shoreline of a salty sea, now
  evaporated.
• April 30, 2004 - Opportunity arrived at
  Endurance Crater.
• June 4, 2004 NASA announced Opportunity will
  descend into Endurance Crater.
• Potential science value gained by sending the
  rover into the crater outweighed the risk of not
  being able to get the rover back.
• June 8, 2004 - Opportunity drives into Endurance
  Crater.
• Opportunity moves forward enough to just get all
  six wheels into the crater.
• Rover enters crater in search of clues to an
  earlier history of water than those found at
  Eagle Crater where rover landed.
• During the final rock investigation inside the
  crater, scientists conclude that Endurance was
  most likely a salt flat, alternately wet and dry,
  rather than a deep-water environment.

36
Opportunity Two Earth Year Timeline (Continued)

• September 22, 2004 - NASA announced Opportunity
  would leave Endurance Crater, visit its discarded
  heat shield, and proceed to Victoria Crater.
• Opportunity examines bedrock along the route
  between Endurance and Victoria craters. The
  texture of the bedrock on the way to Victoria is
  similar to the bottom layer of Endurance Crater
  suggesting a cyclical change in the environment.
• November 11, 2004 - Opportunity starts to leave
  Endurance Crater by retracing its entry path.
• January 19, 2005 - Opportunity finds meteorite
  near its heat shield.
• First meteorite identified on another solar
  system body - none were found on the Moon.
• Composed of iron and nickel, the pitted,
  basketball-sized rock landed on Mars.
• Meteorite that blasted Meteor Crater near
  Winslow, Arizona is similar in composition.
• January 25, 2005 - Opportunity celebrates 1
  Earth year on Mars.
• April 6, 2005 - NASA announced Opportunity would
  visit the Etched Terrain.
• June 4, 2005 - Opportunity escapes from a sand
  dune where it had been stuck since April 26.
• December 12, 2005 - Opportunity marks one
  Martian year (687 Earth days) on Mars.
• Opportunity has returned over 58,000 images and
  traveled over four miles.
• Both rovers have lasted over seven times their
  original life expectancy. Spirit and Opportunity
  were not expected to survive much longer than
  ninety days.
• January 25, 2006 - Opportunity celebrates 2
  Earth years on Mars.