Mars Pathfinder
|
(mirror site at USA) (mirror site at Europe) |
|
|
Peter Smith - November 4:
These images are sub-sections of the "geometrically improved, color enhanced" version of the 360-degree panorama heretofore known as the "Gallery Pan", the first contiguous, uniform panorama taken by the Imager for Mars Pathfinder (IMP) over the course of Sols 8, 9, and 10. Different regions were imaged at different times over the three Martian days to acquire consistent lighting and shadow conditions for all areas of the panorama.
The IMP is a stereo imaging system that, in its fully deployed configuration,
stands 1.8 meters above the Martian surface, and has a resolution of two
millimeters at a range of two meters. In this geometrically improved version
of the panorama, distortion due to a 2.5 degree tilt in the IMP camera
mast has been removed, effectively flattening the horizon. The IMP has
color capability provided by 24 selectable filters -- twelve filters per
"eye". Its red, green, and blue filters were used to take this image. The
color was digitally balanced according to the color transmittance capability
of a high-resolution TV at the Jet Propulsion Laboratory (JPL), and is
dependent on that device. In this color enhanced version of the panorama,
detail in surface features are brought out via changes to saturation and
intensity, holding the original hue constant. A threshold was applied to
avoid changes to the sky.
geometrically improved
geometrically improved, color enhanced
 |
At left is a Lander petal and a metallic mast which is a portion of the low-gain antenna. Misregistration in the antenna and other Lander features is due to parallax in the extreme foreground. Another Lander petal is at the right, showing the fully deployed forward ramp. |
 On
the horizon the double "Twin Peaks" are visible, about 1-2 kilometers away.
The rock "Couch" is the dark, curved rock at right of Twin Peaks. A Lander
petal is visible on the left, showing the fully deployed rear ramp, which
rover Sojourner used to descend to the surface of Mars on July 5. Immediately
to the left of the rear ramp is the rock "Barnacle Bill", which scientists
found to be andesitic, possibly indicating that it is a volcanic rock (a
true andesite) or a physical mixture of particles. Just beyond Barnacle
Bill, rover tracks lead to Sojourner, shown using its Alpha Proton X-Ray
Spectrometer (APXS) instrument to study the large rock "Yogi". Yogi, low
in quartz content, appears to be more primitive than Barnacle Bill, and
appears more like the common basalts found on Earth.
The tracks and circular pattern in the soil leading up to Yogi were part of Sojourner's soil mechanics experiments, in which varying amounts of pressure were applied to the wheels in order to determine physical properties of the soil. During its traverse to Yogi the rover stirred the soil and exposed material from several centimeters in depth. During one of the turns to deploy Sojourner's Alpha Proton X-Ray Spectrometer, the wheels dug particularly deeply and exposed white material. Spectra of this white material show it is virtually identical to the rock "Scooby Doo", and such white material may underlie much of the site. Deflated airbags are visible at the perimeter of the Lander petals. |
 |
At the bottom of the image, two of the Lander petals are visible. At the extreme right of the image, the Atmospheric Structure Instrument and Meteorology package (ASI/MET) mast, with it's three windsocks, is visible. |
 |
The Mars Pathfinder meteorology mast casts a shadow on the lander solar array, as seen in this superpan mosaic. Looking to the southeast during the morning, the windsocks are slightly tilted, indicating the presence of a light wind from the southwest. The MET mast measured the temperature, pressure, and wind speed at the Pathfinder landing site. During the mission, the instrument returned 8.5 million individual measurements from the surface of Mars. |
 |
Mars' innermost natural satellite, Phobos, is seen from the planet's surface in this Pathfinder image taken at night on Sol 56. This picture was acquired by the Imager for Mars Pathfinder (IMP) camera. Using IMP images of Phobos and its companion moon Deimos, the spectral characteristics of the satellites and properties of the Martian atmosphere are determined. |
 |
Mars' outermost natural satellite, Deimos, is seen from the planet's surface in this Pathfinder image taken at night on Sol 4. This picture was acquired by the Imager for Mars Pathfinder (IMP) camera. Using IMP images of Deimos and its companion moon Phobos, the spectral characteristics of the satellites and properties of the Martian atmosphere are determined. |
| The Twin Peaks are modest-size hills to
the southwest of the Mars Pathfinder landing site. They were discovered
on the first panoramas taken by the IMP camera on the 4th of July, 1997,
and subsequently identified in Viking Orbiter images taken over 20 years
ago. The peaks are approximately 30-35 meters (~100 feet) tall. North Twin
is approximately 860 meters (2800 feet) from the lander, and South Twin
is about a kilometer away (3300 feet). The scene includes rocky ridges
and swales (or "hummocks") of flood debris that range from a few tens of
meters away from the lander to the distance of South Twin Peak. The large
rock at the right edge of the scene is nicknamed "Hippo." This rock is
about a meter (3 feet) across and 25 meters (80 feet) distant.
|
| The "Big Crater" is actually a relatively
small Martian crater to the southeast of the Mars Pathfinder landing site.
It is 1500 meters (4900 feet) in diameter, or about the same size as Meteor
Crater in Arizona. Superimposed on the rim of Big Crater (the central part
of the rim as seen here) is a smaller crater nicknamed "Rimshot Crater."
The distance to this smaller crater, and the nearest portion of the rim
of Big Crater, is 2200 meters (7200 feet). To the right of Big Crater,
south from the spacecraft, almost lost in the atmospheric dust "haze,"
is the large streamlined mountain nicknamed "Far Knob." This mountain is
over 450 meters (1480 feet) tall, and is over 30 kilometers (19 miles)
from the spacecraft. Another, smaller and closer knob, nicknamed "Southeast
Knob" can be seen as a triangular peak to the left of the flanks of the
Big Crater rim. This knob is 21 kilometers (13 miles) southeast from the
spacecraft.
The larger features visible in this scene - Big Crater, Far Knob, and Southeast Knob - were discovered on the first panoramas taken by the IMP camera on the 4th of July, 1997, and subsequently identified in Viking Orbiter images taken over 20 years ago. The scene includes rocky ridges and swales or "hummocks" of flood debris that range from a few tens of meters away from the lander to the distance of South Twin Peak. The largest rock in the nearfield, just left of center in the foreground, nicknamed "Otter", is about 1.5 meters (4.9 feet) long and 10 meters (33 feet) from the spacecraft.
|
| This panorama of the region to the northeast of
the lander was constructed to support the Sojourner Rover Team's plans
to conduct an "autonomous traverse" to explore the terrain away from the
lander after science objectives in the lander vicinity had been met. The
large, relatively bright surface in the foreground, about 10 meters (33
feet) from the spacecraft, in this scene is "Baker's Bench." The
large, elongated rock left of center in the middle distance is "Zaphod."
|
|
Mars Pathfinder was successfully launched
on December 4, 1996, at 1:58 am EST (10:58 pm PST) and is on its way to
the Red Planet! All systems are healthy.
Mars Pathfinder launch was delayed on December 3, because of a synch error with a console in the blockhouse. This occasioned a mandatory recycle of the countdown and a hold at T-1 minute. The Mars Pathfinder spacecraft arrived at Mars on July 4, 1997. Launched before, on November 7, 1996, Mars Global Surveyor will arrive later: on September, 1997, because of its longer trajectory. Mars Pathfinder used a parachute and airbags to avoid crashing on the Mars surface. It landed a microrover weighting 11.5 kg and provided with a camera and several instruments to analize the martian soil. |
 |
Hitting the thin upper atmospere of
Mars at more than 17,000 miles per hour (27,000 km/h), the entry vehicle's
heat shield slowed the craft to 900 miles per hour (1,450 km/s) in about
two minutes. An onboard computer (32 bits, 4Mb RAM, 64 Mb mass storage)
deployed then a large parachute to slow the lander down to about 155 miles
per hour (250 km/h) in the rarified atmosphere of Mars, wich is only 1/100th
as dense as Earth's.
The airbags were inflated at about 330 feet (100 m) above the surface. The rocket motors were then fired, stopping the lander some 40 feet (12 meters) above the Martian ground. The parachute was released, and the lander fell to the ground, bouncing and rolling until it stopped. Within about an hour, the air bags were deflated and partially retracted. The three solar panels (petals) were opened and the lander was finally stand up. After taking some photographs of the landing site, engineers instructed the microrover to drive off and begin exploring the immediate surroundings. |
 |
The landing site is on the Ares
Vallis region of Mars, a large outwash plain near Chryse Planitia.
The site is at 19.5ºN and 32.8ºW, 527 miles (850 km) southeast
of the location of Viking Lander 1, wich in 1976 became the first spacecraft
to land on Mars. Mars Pathfinder will be the first to land on Mars since
the twin Vikings landers arrived almost 20 years ago.
More than 60 scientists from the United States and Europe participated in a workshop where the Ares Valley was choosed between several potential landing sites. Even though the exact origins of the samples would not be known, the chance of sampling a variety of rocks in a small area coul reveal a lot about Mars. |
