Changes: Mars Pathfinder

Latest revision as of 12:48, 16 July 2016

For the unmanned aerial vehicles, see NASA Pathfinder.

Template:Infobox spaceflight

Mars Pathfinder (MESUR Pathfinder^[1]^[2]) is an American robotic spacecraft that landed a base station with a roving probe on Mars in 1997. It consisted of a lander, renamed the Carl Sagan Memorial Station, and a lightweight (10.6 kg/23 lb) wheeled robotic Mars rover named Sojourner,^[3] which became the first rover to operate outside the Earth-Moon system.

Launched on December 4, 1996 by NASA aboard a Delta II booster a month after the Mars Global Surveyor was launched, it landed on July 4, 1997 on Mars's Ares Vallis, in a region called Chryse Planitia in the Oxia Palus quadrangle. The lander then opened, exposing the rover which conducted many experiments on the Martian surface. The mission carried a series of scientific instruments to analyze the Martian atmosphere, climate, geology and the composition of its rocks and soil. It was the second project from NASA's Discovery Program, which promotes the use of low-cost spacecraft and frequent launches under the motto "cheaper, faster and better" promoted by the then administrator, Daniel Goldin. The mission was directed by the Jet Propulsion Laboratory (JPL), a division of the California Institute of Technology, responsible for NASA's Mars Exploration Program. The project manager was JPL's Tony Spear.

This mission was the first of a series of missions to Mars that included rovers, and was the first successful lander since the two Vikings landed on the red planet in 1976. Although the Soviet Union successfully sent rovers to the Moon as part of the Lunokhod program in the 1970s, its attempts to use rovers in its Mars program failed.

In addition to scientific objectives, the Mars Pathfinder mission was also a "proof-of-concept" for various technologies, such as airbag-mediated touchdown and automated obstacle avoidance, both later exploited by the Mars Exploration Rover mission. The Mars Pathfinder was also remarkable for its extremely low cost relative to other unmanned space missions to Mars. Originally, the mission was conceived as the first of the Mars Environmental Survey (MESUR) program.

Mission objectives[]

To prove that the development of "faster, better and cheaper" spacecraft was possible (with three years for development and a cost under $150 million).
To show that it was possible to send a load of scientific instruments to another planet with a simple system and at one fifteenth the cost of a Viking mission. (For comparison, the Viking missions cost $935 million in 1974^[4] or $3.5 billion in 1997 dollars.)
To demonstrate NASA's commitment to low-cost planetary exploration by finishing the mission with a total expenditure of $280 million, including the launch vehicle and mission operations.

Science experiments[]

The Mars Pathfinder conducted different investigations on the Martian soil using three scientific instruments. The lander contained a stereoscopic camera with spatial filters on an expandable pole called Imager for Mars Pathfinder (IMP),^[5]^[6] and the Atmospheric Structure Instrument/Meteorology Package (ASI/MET)^[7] which acts as a Mars meteorological station, collecting data about pressure, temperature, and winds. The MET structure included three windsocks mounted at three heights on a pole, the topmost at about one meter (yard) and generally registered winds from the West.^[8]

The Sojourner rover had an Alpha Proton X-ray Spectrometer (APXS),^[9] which was used to analyze the components of the rocks and soil. The rover also had two black-and-white cameras and a color one. These instruments could investigate the geology of the Martian surface from just a few millimeters to many hundreds of meters, the geochemistry and evolutionary history of the rocks and surface, the magnetic and mechanical properties of the land, as well as the magnetic properties of the dust, atmosphere and the rotational and orbital dynamics of the planet.

Three navigation cameras were on board the rover: Two black and white 0.3-megapixel cameras were located on the front (768 horizontal pixels × 484 vertical pixels configured in 4×4+100 pixel blocks), coupled with five laser stripe projectors, which enabled stereoscopic images to be taken along with measurements for hazard detection on the rover's path. A third camera with the same resolution but taking color images was located on the back, near the APXS, and rotated by 90°. It provided images of the APXS's target area and the rover's tracks on the ground. The pixels of this colour camera were arranged in such a way, that out of the 16 pixel of a 4×4 pixel block, 12 pixel were sensitive to green, 2 pixel to red and 2 pixel were sensitive to infrared as well as blue. As all cameras had lenses made out of zinc selenide, which blocks light below a wavelength of 500 nm, no blue light actually reached these "blue/infrared" pixels, which therefore recorded only infrared.

All three cameras were CCDs manufactured by Eastman Kodak Company, and were controlled by the rover's CPU. They all had auto-exposure and capabilities for handling bad pixels, and the image parameters (exposure time, compression used, etc.) were included in the transmitted images as part of the image header. The rover could compress the front cameras' images using the block truncation coding (BTC) algorithm, but it could only do the same for the back camera's images if the colour information was discarded. The cameras' optical resolution was sufficient to resolve 0.6 cm details across a 0.65 m range.^[10]

Pathfinder lander[]

Imager for Mars Pathfinder (IMP), (includes magnetometer and anemometer)
Atmospheric and meteorological sensors (ASI/MET)

Sojourner rover[]

Main article: Sojourner (rover)

Imaging system (three cameras: front B&W stereo,^[10] 1 rear color)
Laser striper hazard detection system
Alpha Proton X-ray Spectrometer (APXS)
Wheel Abrasion Experiment
Materials Adherence Experiment
Accelerometers

Landing site[]

The landing site was an ancient flood plain in Mars's northern hemisphere called "Ares Vallis" ("the valley of Ares", the ancient Greek equivalent of the ancient Roman deity Mars) and is among the rockiest parts of Mars. Scientists chose it because they found it to be a relatively safe surface to land on and one that contained a wide variety of rocks deposited during a catastrophic flood. After the landing, at Template:Coord,^[11] succeeded, the landing site received the name The Carl Sagan Memorial Station in honor of the astronomer.

Template:Magnify iconMars Pathfinder panorama of landing site taken by IMP

Entry, descent and landing[]

Mars Pathfinder entered the Martian atmosphere and landed using an innovative system involving an entry capsule, a supersonic parachute, followed by solid rockets and large airbags to cushion the impact.

Mars Pathfinder directly entered Mars atmosphere in a retrograde direction from a hyperbolic trajectory at 6.1 km/s using an atmospheric entry aeroshell (capsule) that was derived from the original Viking Mars lander design. The aeroshell consisted of a back shell and a specially designed ablative heatshield to slow to 370 m/s (830 mph) where a supersonic disk-gap-band parachute was inflated to slow its descent through the thin Martian atmosphere to 68 m/s (about 160 mph). The lander's on-board computer used redundant on-board accelerometers to determine the timing of the parachute inflation. Twenty seconds later the heatshield was pyrotechnically released. Another twenty seconds later the lander was separated and lowered from the backshell on a 20 m bridle (tether). When the lander reached 1.6 km above the surface, a radar was used by the on-board computer to determine altitude and descent velocity. This information was used by the computer to determine the precise timing of the landing events that followed.

Once the lander was 355 m above the ground, airbags were inflated in less than a second using three catalytically cooled solid rocket motors that served as gas generators. The airbags were made of 4 inter-connected multi-layer vectran bags that surrounded the tetrahedron lander. They were designed and tested to accommodate grazing angle impacts as high as 28 m/s. However, as the airbags were designed for no more than about 15 m/s vertical impacts, three solid retrorockets were mounted above the lander in the backshell. These were fired at 98 m above the ground. The lander's on-board computer estimated the best time to fire the rockets and cut the bridle so that the lander velocity would be reduced to about 0 m/s between 15 and 25 m above the ground. After 2.3 seconds, while the rockets were still firing, the lander cut the bridle loose about 21.5 m above the ground and fell to the ground. The rockets flew up and away with the backshell and parachute (they have since been sighted by orbital images). The lander impacted at 14 m/s and limited the impact to only 18 G of deceleration. The first bounce was 15.7 m high and continued bouncing for at least 15 additional bounces (accelerometer data recording did not continue through all of the bounces).

The entire entry, descent and landing (EDL) process was completed in 4 minutes.^[12]

Once the lander stopped rolling, the airbags deflated and retracted toward the lander using four winches mounted on the lander "petals". Designed to right itself from any initial orientation, the lander happened to roll right side up onto its base petal. 74 minutes after landing, the petals were deployed with Sojourner rover and the solar panels attached on the inside.

The lander arrived at night at 2:56:55 Mars local solar time (16:56:55 UTC) on July 4, 1997. The lander had to wait until sunrise to send its first digital signals and images to Earth. The landing site was located at 19.30° north latitude and 33.52° west longitude in Ares Vallis, only 19 kilometres southwest of the center of the 200 km wide landing site ellipse. During Sol 1, the first Martian solar day the lander spent on the planet, the lander took pictures and made some meteorologic measurements. Once the data was received, the engineers realized that one of the airbags hadn't fully deflated and could be a problem for the forthcoming traverse of Sojourner's descent ramp. To solve the problem, they sent commands to the lander to raise one of its petals and perform additional retraction to flatten the airbag. The procedure was a success and on Sol 2, Sojourner was released, stood up and backed down one of two ramps.

The Mars Pathfinder entry descent and landing system design was used (with some modification) on the Mars Exploration Rover mission. Likewise, many design aspects of the Sojourner rover (e.g. the rocker-bogie mobility architecture and the navigation algorithms) were also successfully used on the Mars Exploration Rover mission.

Rover operations[]

Sojourner deployment[]

The Sojourner rover exit from the lander occurred on Sol 2, after its landing on July 4, 1997. As the next sols progressed it approached some rocks, which the scientists named "Barnacle Bill", "Yogi", and "Scooby-Doo", after famous cartoon characters. The rover made measurements of the elements found in those rocks and in the martian soil, while the lander took pictures of the Sojourner and the surrounding terrain, in addition to making climate observations.

The Sojourner is a six-wheeled 65 cm long vehicle, 48 cm wide, 30 cm tall and weighing 10.5 kg.^[13] Its maximum speed reached one centimeter per second. Sojourner travelled approximately 100 metres in total, never more than 12 m from the Pathfinder station. During its 83 sols of operation, it sent 550 photographs to Earth and analyzed the chemical properties of 16 locations near the lander. (See also Space exploration rovers)

Sojourner's rock analysis[]

The first analysis on a rock started on Sol 3 with Barnacle Bill. The Alpha Particle X-ray Spectrometer (APXS) was used to determine its composition, the spectrometer taking ten hours to make a full scan of the sample. It found all the elements except hydrogen, which constitutes just 0.1 percent of the rock's or soil's mass.

The APXS works by irradiating rocks and soil samples with alpha particles (helium nuclei, which consist of two protons and two neutrons). The results indicated that "Barnacle Bill" is much like Earth's andesites, confirming past volcanic activity. The discovery of andesites shows that some Martian rocks have been remelted and reprocessed. On Earth, Andesite forms when magma sits in pockets of rock while some of the iron and magnesium settle out. Consequently, the final rock contains less iron and magnesiums and more silica. Volcanic rocks are usually classified by comparing the relative amount of alkalis (Na₂O and K₂O) with the amount of silica (SiO₂). Andesite is different from the rocks found in meteorites that have come from Mars.^[14]^[15]^[16]

Analysis of the Yogi rock again using the APXS showed that it was a basaltic rock, more primitive than Barnacle Bill. Yogi's shape and texture show that it was probably deposited there by a flood.

Another rock, named Moe, was found to have certain marks on its surface, demonstrating erosion caused by the wind. Most rocks analyzed showed a high content of silicon. In another region known as Rock Garden, Sojourner encountered crescent moon-shaped dunes, which are similar to crescentic dunes on Earth.

By the time that final results of the mission were described in a series of articles in the journal Science (December 5, 1997), it was believed that the rock Yogi contained a coating of dust, but was similar to the rock Barnacle Bill. Calculations suggest that the two rocks contain mostly the minerals orthopyroxene (magnesium-iron silicate), feldspars (aluminum silicates of potassium, sodium, and calcium), quartz (silicon dioxide), with smaller amounts of magnetite, ilmenite, iron sulfide, and calcium phosphate.^[14]^[15]^[16]

Template:Magnify iconAnnotated panorama of rocks near the Sojourner Rover (December 5, 1997)

On-board computer[]

See also: Comparison of embedded computer systems on board the Mars rovers

The embedded computer on board the Sojourner rover was based around the 2 MHz^[17] Intel 80C85 CPU with 512 KB of RAM and 176 KB of flash memory solid-state storage, running a cyclic executive.^[18]

The computer of the "Pathfinder" lander was a Radiation Hardened IBM Risc 6000 Single Chip (Rad6000 SC) CPU with 128 MB of RAM and 6 MB of EEPROM^[19]^[20] and its operating system was VxWorks.^[21]

The mission was jeopardised by a concurrent software bug in the lander,^[22] which had been found in preflight testing but was deemed a glitch and therefore given a low priority as it only occurred in certain unanticipated heavy-load conditions, and the focus was on verifying the entry and landing code. The problem, which was reproduced and corrected from Earth using a laboratory duplicate thanks to the logging and debugging functionality enabled in the flight software, was due to computer resets caused by priority inversion. No scientific or engineering data was lost after a computer reset, but all the following operations were interrupted until the next day.^[23]^[24] Four resets occurred (on July 5, 10, 11 and 14) during the mission,^[25] before patching the software on July 21 to enable priority inheritance.^[26]

Results from Pathfinder[]

The lander sent more than 2.3 billion bits of information including 16,500 pictures and made 8.5 million measurements of the atmospheric pressure, temperature and wind speed.^[27]

By taking multiple images of the sky at different distances from the Sun, scientists were able to determine that the size of the particles in the pink haze was about one micrometre in radius. The color of some soils was similar to that of an iron oxyhydroxide phase which would support the theory of a warmer and wetter climate in the past.^[28] Pathfinder carried a series of magnets to examine the magnetic component of the dust. Eventually, all but one of the magnets developed a coating of dust. Since the weakest magnet did not attract any soil, it was concluded that the airborne dust did not contain pure magnetite or just one type of maghemite. The dust probably was an aggregate possibly cemented with ferric oxide (Fe₂O₃).^[29] Using much more sophisticated instruments, Mars Spirit Rover found that magnetite could explain the magnetic nature of the dust and soil on Mars. Magnetite was found in the soil and that the most magnetic part of the soil was dark. Magnetite is very dark.^[30]

Using Doppler tracking and two-way ranging, scientists added earlier measurements from the Viking landers to determine that the non-hydrostatic component of the polar moment of inertia is due to the Tharsis bulge and that the interior is not melted. The central metallic core is between 1300 km and 2000 km in radius.^[14]

End of mission[]

Although the mission was planned to last from a week to a month, the rover operated successfully for almost three months. Communication failed after 7 October,^[31] with a final data transmission received from Pathfinder at 10:23 UTC on September 27, 1997. Mission managers tried to restore full communications during the following five months, but the mission was terminated on March 10, 1998. During the extended operation a high-resolution stereo panorama of the surrounding terrain was being made, and the Sojourner rover was to visit a distant ridge, but the panorama was only about one-third completed and the ridge visit had not begun when communication failed.^[31]

The on-board battery—designed to operate for one month—may have failed after repeated charging and discharging. The battery was used to heat the probe's electronics to slightly above the expected nighttime temperatures on Mars. With the failure of the battery, colder-than-normal temperatures may have caused vital parts to break, leading to loss of communications.^[31]^[32]

After the landing, Pathfinder was renamed as the Sagan Memorial Station in honor of astronomer and planetologist Carl Sagan. The mission had exceeded its goals in the first month.

Mars Reconnaissance Orbiter spotted Pathfinder in January 2007 (left).^[33]^[34]

Naming the rover[]

Pathfinder01 — *Sojourner* takes its Alpha Particle X-ray Spectrometer measurement of the Yogi Rock

The name Sojourner was chosen for the Mars Pathfinder rover after a year-long, worldwide competition in which students up to 18 years old were invited to select a heroine and submit an essay about her historical accomplishments. The students were asked to address in their essays how a planetary rover named for their heroine would translate these accomplishments to the Martian environment.

Initiated in March 1994 by The Planetary Society of Pasadena, California, in cooperation with NASA's Jet Propulsion Laboratory (JPL), the contest got under way with an announcement in the January 1995 issue of the National Science Teachers Association's magazine Science and Children, circulated to 20,000 teachers and schools across the nation.^[35]

The winning essay suggested naming the rover for Sojourner Truth was selected from among 3500 essays in a NASA/JPL sponsored contest on a heroine and her accomplishments. The essay selected was by then 12-year-old Valerie Ambroise of Bridgeport, CT. The second place prize winner was Deepti Rohatgi, 18, of Rockville, MD, who suggested Marie Curie. Other popular suggestions included Sacajewea and Amelia Earhart.^[36]

Honors[]

In 1997, the Sojourner Team was awarded a JPL Award for Technical Excellence
On October 21, 1997, at the Geological Society of America's annual meeting in Salt Lake City, Utah, Sojourner was awarded honorary membership in the Planetary Geology Division of the society^[37]
In 2003, Sojourner was inducted into the Robot Hall of Fame

Image map of Mars[]

The following image map of the planet Mars has embedded links to geographical features in addition to the noted Rover and Lander locations. Click on the features and you will be taken to the corresponding article pages. North is at the top; Elevations: red (higher), yellow (zero), blue (lower). Template:Mars map indicating landers

In popular culture[]

In the novel The Martian by Andy Weir, the protagonist, who is stranded alone on Mars, travels to the long-dead Pathfinder site and returns it to his base in an attempt to communicate with Earth. The character even notes the "Twin Peaks" as a landmark.^[38] This scenario was featured in the 2015 film adaptation of the novel.
In the 2000 film Red Planet, astronauts stranded on Mars make a makeshift radio from parts of the Pathfinder. They use the radio to communicate with their spaceship.

Notes[]

↑ Cite error: Invalid <ref> tag; no text was provided for refs named NASA-Sojourner
↑ Template:Cite news
↑ "Mars Pathfinder". NASA. http://mpfwww.jpl.nasa.gov/missions/past/pathfinder.html. Retrieved June 10, 2015.
↑ Template:Cite book
↑ Template:Cite journal
↑ Template:Cite journal
↑ Template:Cite journal
↑ "Windsocks on Mars". JPL/NASA Mars Pathfinder. 2005. http://mars.jpl.nasa.gov/MPF/science/windsocks.html. Retrieved June 10, 2015.
↑ Template:Cite journal
↑ ^10.0 ^10.1 "Rover Camera Instrument Description". NASA. http://pdsimg.jpl.nasa.gov/data/mpfr-m-rvrcam-2-edr-v1.0/mprv_0001/document/rcinst.htm. Retrieved June 10, 2015.
↑ "Mars Pathfinder Science Results". NASA. http://mpfwww.jpl.nasa.gov/MPF/science/geology.html.
↑ "Entry Descent and Landing". JPL/NASA Mars Pathfinder. 2005. http://marsprogram.jpl.nasa.gov/MPF/mpf/edl/edl1.html. Retrieved June 10, 2015.
↑ "Mars – the search for life" (PDF). NASA. March 4, 2009. http://mepag.jpl.nasa.gov/meeting/mar-09/02_MEPAG_McCuistion_Mar_09.pdf. Retrieved March 28, 2009.
↑ ^14.0 ^14.1 ^14.2 Golombek, M. et al. 1997. Overview of the Mars Pathfinder Mission and Assessment of Landing Site Predictions. Science. Science: 278. pp. 1743–1748
↑ ^15.0 ^15.1 "APXS Composition Results". NASA. http://nssdc.gsfc.nasa.gov/planetary/marspath/apxs.html. Retrieved June 10, 2015.
↑ ^16.0 ^16.1 Template:Cite journal
↑ "Mars Pathfinder FAQs - Sojourner CPU". NASA. http://mars.jpl.nasa.gov/MPF/rover/faqs_sojourner.html#cpu. Retrieved June 10, 2015.
↑ Template:Cite journal
↑ ""QUESTION: What type of computer is the Pathfinder utilizing? ..." (NASA Quest Q&A)". NASA. 1997. http://quest.arc.nasa.gov/mars/ask/about-mars-path/pathfinder_computer.txt. Retrieved July 21, 2015.
↑ ""QUESTION: When it was designed, why was only a single 80C85 CPU used? ..." (NASA Quest Q&A)". NASA. 1997. http://quest.arc.nasa.gov/mars/ask/about-rover/Why_to_use_a_80C85_microprocessor_in_Rover_.txt. Retrieved July 21, 2015.
↑ "Wind River Powers Mars Exploration Rovers—Continues Legacy as Technology Provider for NASA's Space Exploration". Wind River Systems. June 6, 2003. http://www.windriver.com/news/press/pr.html?ID=314. Retrieved August 28, 2009.
↑ Parallel sparking: Many chips make light work, Douglas Heaven, New Scientist magazine, issue 2930, 19 August 2013, p44. Online (by subscription)
↑ Reeves, Glenn E. (December 15, 1997). "What really happened on Mars? - Authoritative Account". Microsoft.com. http://research.microsoft.com/en-us/um/people/mbj/Mars_Pathfinder/Authoritative_Account.html. Retrieved 10 June 2015.
↑ Jones, Michael B. (December 16, 1997). "What really happened on Mars?". Microsoft.com. http://research.microsoft.com/en-us/um/people/mbj/Mars_Pathfinder/. Retrieved June 10, 2015.
↑ "The Mars Pathfinder Mission Status Reports — Second Week". Office of the Flight Operations Manager – Mars Pathfinder Project. http://www.oarval.org/missionsr2.htm.
↑ "The Mars Pathfinder Mission Status Reports — Third Week". Office of the Flight Operations Manager – Mars Pathfinder Project. http://www.oarval.org/missionsr3.htm.
↑ "Mars Pathfinder and Sojourner". NASA. http://www.nasa.gov/mission_pages/mars-pathfinder/. Retrieved June 10, 2015.
↑ Smith, P. et al. 1997. Results from the Mars Pathfinder Camera Science: 278. 1758–1765
↑ Hviid, S. et al. 1997. Magnetic Properties Experiments on the Mars Pathfinder Lander: Preliminary Results. Science:278. 1768–1770.
↑ Bertelsen, P. et al. 2004. Magnetic Properties Experiments on the Mars Exploration rover Spirit at Gusev Crater. Science: 305. 827–829.
↑ ^31.0 ^31.1 ^31.2 "Mars Pathfinder Nearing Its End". sciencemag.org. http://news.sciencemag.org/sciencenow/1997/10/27-04.html. Retrieved June 10, 2015.
↑ NASA facts - Mars Pathfinder
↑ Template:Cite news
↑ "Mars Pathfinder Landing Site and Surroundings". NASA. http://www.nasa.gov/mission_pages/MRO/multimedia/pia09105.html. Retrieved June 10, 2015.
↑ "NASA Names First Rover to Explore the Surface of Mars". NASA. http://mars.jpl.nasa.gov/MPF/rover/name.html. Retrieved November 29, 2010.
↑ "Pathfinder Rover Gets Its Name". NASA. http://mars.jpl.nasa.gov/MPF/rover/name.html. Retrieved June 10, 2015.
↑ Template:Cite journal
↑ Template:Cite book

References[]

Template:SPATRAcite

JPL Mars Pathfinder article
Mars Pathfinder Litograph Set, NASA. (1997)
Poster: Mars Pathfinder –Roving the Red Planet, NASA. (1998)
Deep Space Chronicle: A Chronology of Deep Space and Planetary Probes 1958–2000, Asif A. Siddiqi. Monographs in Aerospace History, #24. June 2002, NASA History Office.
"Return to Mars", article by William R. Newcott. National Geographic, pp. 2–29. Vol. 194, 2nd edition – August 1998.
"La misión Pathfinder –rebautizada Carl Sagan Memorial Station, en memoria del célebre astrónomo-, paso a paso todo Marte", de J. Roberto Mallo. Conozca Más, págs. 90–96. Edición número 106 – agosto de 1997.
"Un espía que anda por Marte", de Julio Guerrieri. Descubrir, págs. 80–83. Edición número 73 – agosto de 1997.
"Mars Pathfinder: el inicio de la conquista de Marte" EL Universo, Enciclopedia de la Astronomía y el Espacio, Editorial Planeta-De Agostini, págs. 58–60. Tomo 5. (1997)
Sojourner: An Insider's View of the Mars Pathfinder Mission, by Andrew Mishkin, Senior Systems Engineer, NASA Jet Propulsion Laboratory. ISBN 0-425-19199-0
Experiences with operations and autonomy of the Mars Pathfinder microrover, A. H. Mishkin, J. C. Morrison, T. T. Nguyen, H. W. Stone, B. K. Cooper and B. H. Wilcox. In Proceedings of the IEEE Aerospace Conference, Snowmass, CO 1998.

External links[]

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Wikimedia Commons has media related to Category:Mars Pathfinder.

Mars Pathfinder NASA/JPL Website
Mars Pathfinder 360 View (released February 26, 2016).
Super-Resolution Stereo Pairs of "Twin Peaks"
Mars Pathfinder Mission Profile by NASA's Solar System Exploration
Ted Stryk's Mars Pathfinder page
"A Crawl On Mars"—Ted Stryk's Sojourner rover page
NASA Office of Space Science
JPL—Mars Exploration Rover Mission
Authoritative Account of MPF Reset Issue—discussion of the software problems on the Pathfinder spacecraft
A Little Rock on Mars—children's story about the Pathfinder landing
Sojourner rover replica Template:Language icon—description and images of a full scale functional replica of the Sojourner rover
Pathfinder landing site as seen from orbit by Mars Reconnaissance Orbiter
Paper model (source)
Magnetic Properties Experiment

Template:Carl Sagan

This page uses Creative Commons Licensed content from Wikipedia (view authors).

[NASA-Sojourner-1] Cite error: Invalid <ref> tag; no text was provided for refs named NASA-Sojourner

[2] Template:Cite news

[3] "Mars Pathfinder". NASA. http://mpfwww.jpl.nasa.gov/missions/past/pathfinder.html. Retrieved June 10, 2015.

[4] Template:Cite book

[5] Template:Cite journal

[6] Template:Cite journal

[7] Template:Cite journal

[8] "Windsocks on Mars". JPL/NASA Mars Pathfinder. 2005. http://mars.jpl.nasa.gov/MPF/science/windsocks.html. Retrieved June 10, 2015.

[9] Template:Cite journal

[sojcam-10] 10.0 ^10.1 "Rover Camera Instrument Description". NASA. http://pdsimg.jpl.nasa.gov/data/mpfr-m-rvrcam-2-edr-v1.0/mprv_0001/document/rcinst.htm. Retrieved June 10, 2015.

[11] "Mars Pathfinder Science Results". NASA. http://mpfwww.jpl.nasa.gov/MPF/science/geology.html.

[12] "Entry Descent and Landing". JPL/NASA Mars Pathfinder. 2005. http://marsprogram.jpl.nasa.gov/MPF/mpf/edl/edl1.html. Retrieved June 10, 2015.

[13] "Mars – the search for life" (PDF). NASA. March 4, 2009. http://mepag.jpl.nasa.gov/meeting/mar-09/02_MEPAG_McCuistion_Mar_09.pdf. Retrieved March 28, 2009.

[Golombek,_M_1997-14] 14.0 ^14.1 ^14.2 Golombek, M. et al. 1997. Overview of the Mars Pathfinder Mission and Assessment of Landing Site Predictions. Science. Science: 278. pp. 1743–1748

[nssdc.gsfc.nasa.gov-15] 15.0 ^15.1 "APXS Composition Results". NASA. http://nssdc.gsfc.nasa.gov/planetary/marspath/apxs.html. Retrieved June 10, 2015.

[Bruckner,_J._2001-16] 16.0 ^16.1 Template:Cite journal

[17] "Mars Pathfinder FAQs - Sojourner CPU". NASA. http://mars.jpl.nasa.gov/MPF/rover/faqs_sojourner.html#cpu. Retrieved June 10, 2015.

[ieeecomputer-18] Template:Cite journal

[19] ""QUESTION: What type of computer is the Pathfinder utilizing? ..." (NASA Quest Q&A)". NASA. 1997. http://quest.arc.nasa.gov/mars/ask/about-mars-path/pathfinder_computer.txt. Retrieved July 21, 2015.

[20] ""QUESTION: When it was designed, why was only a single 80C85 CPU used? ..." (NASA Quest Q&A)". NASA. 1997. http://quest.arc.nasa.gov/mars/ask/about-rover/Why_to_use_a_80C85_microprocessor_in_Rover_.txt. Retrieved July 21, 2015.

[Wind_River-21] "Wind River Powers Mars Exploration Rovers—Continues Legacy as Technology Provider for NASA's Space Exploration". Wind River Systems. June 6, 2003. http://www.windriver.com/news/press/pr.html?ID=314. Retrieved August 28, 2009.

[22] Parallel sparking: Many chips make light work, Douglas Heaven, New Scientist magazine, issue 2930, 19 August 2013, p44. Online (by subscription)

[23] Reeves, Glenn E. (December 15, 1997). "What really happened on Mars? - Authoritative Account". Microsoft.com. http://research.microsoft.com/en-us/um/people/mbj/Mars_Pathfinder/Authoritative_Account.html. Retrieved 10 June 2015.

[24] Jones, Michael B. (December 16, 1997). "What really happened on Mars?". Microsoft.com. http://research.microsoft.com/en-us/um/people/mbj/Mars_Pathfinder/. Retrieved June 10, 2015.

[25] "The Mars Pathfinder Mission Status Reports — Second Week". Office of the Flight Operations Manager – Mars Pathfinder Project. http://www.oarval.org/missionsr2.htm.

[26] "The Mars Pathfinder Mission Status Reports — Third Week". Office of the Flight Operations Manager – Mars Pathfinder Project. http://www.oarval.org/missionsr3.htm.

[jplpathfinder-27] "Mars Pathfinder and Sojourner". NASA. http://www.nasa.gov/mission_pages/mars-pathfinder/. Retrieved June 10, 2015.

[28] Smith, P. et al. 1997. Results from the Mars Pathfinder Camera Science: 278. 1758–1765

[29] Hviid, S. et al. 1997. Magnetic Properties Experiments on the Mars Pathfinder Lander: Preliminary Results. Science:278. 1768–1770.

[30] Bertelsen, P. et al. 2004. Magnetic Properties Experiments on the Mars Exploration rover Spirit at Gusev Crater. Science: 305. 827–829.

[batteryfailure-31] 31.0 ^31.1 ^31.2 "Mars Pathfinder Nearing Its End". sciencemag.org. http://news.sciencemag.org/sciencenow/1997/10/27-04.html. Retrieved June 10, 2015.

[nasafacts-32] NASA facts - Mars Pathfinder

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[34] "Mars Pathfinder Landing Site and Surroundings". NASA. http://www.nasa.gov/mission_pages/MRO/multimedia/pia09105.html. Retrieved June 10, 2015.

[35] "NASA Names First Rover to Explore the Surface of Mars". NASA. http://mars.jpl.nasa.gov/MPF/rover/name.html. Retrieved November 29, 2010.

[36] "Pathfinder Rover Gets Its Name". NASA. http://mars.jpl.nasa.gov/MPF/rover/name.html. Retrieved June 10, 2015.

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@@ Line 5: / Line 5: @@
 | image                 = Mars Pathfinder Lander preparations.jpg
-| image_caption         = ''Pathfinder'' and ''Sojourner'' at the JPL in October 1996, being 'folded' into its launch position.<ref name="NASA-Sojourner">{{cite web |last=Nelson |first=Jon |title=Mars Pathfinder / Sojourner Rover |url=http://www.jpl.nasa.gov/missions/details.php?id=5913 |date= |work=[[NASA]]|accessdate=February 2, 2014 }}</ref>
+| image_caption         = ''Pathfinder'' and ''Sojourner'' at the JPL in October 1996, being 'folded' into its launch position.<ref name="NASA-Sojourner">{{cite web |last=Nelson |first=Jon |title=Mars Pathfinder / Sojourner Rover |url=http://www.jpl.nasa.gov/missions/details.php?id=5913 |date= |work=[[NASA]]|accessdate=February 2, 2014}}</ref>
 | image_alt             = A group of scientists, all wearing white protective clothing, gather around a spacecraft as it's being folded into its launch position; a triangular pyramid shape.
 | image_size            = 300px
@@ Line 20: / Line 20: @@
 | power                 = ''Pathfinder'': 35 W<br>''Sojourner'': 13 W
-| launch_date           = {{start date|1996|12|04}} 06:58:07 [[Coordinated Universal Time|UTC]]<br/><small>({{Age in years, months and days|year=1996|month=12|day=04}} ago)</small>
+| launch_date           = {{start date|1996|12|04}} 06:58:07 UTC<br/><small>({{Age in years, months and days|year=1996|month=12|day=04}} ago)</small>
 | launch_rocket         = [[Delta II]] 7925 (#D240)
 | launch_site           = [[Cape Canaveral Air Force Station|Cape Canaveral]] [[Cape Canaveral Air Force Station Space Launch Complex 17|SLC-17]]
 | launch_contractor     = None<ref>{{cite web|first=Erik|last=Conway|url=http://www.jpl.nasa.gov/jplhistory/the90/pathfinder-t.php|title=The Discovery Program: Mars Pathfinder|work=[[Jet Propulsion Laboratory]]|year=2015|accessdate=June 10, 2015}}</ref>
-| last_contact          = {{start date|1997|09|27}} 10:23 [[Coordinated Universal Time|UTC]]<br/><small>({{Age in years, months and days|year=1997|month=09|day=27}} ago)</small>
+| last_contact          = {{start date|1997|09|27}} 10:23 UTC<br/><small>({{Age in years, months and days|year=1997|month=09|day=27}} ago)</small>
-|interplanetary         =
+|interplanetary         ={{Infobox spaceflight/IP
-  {{Infobox spaceflight/IP
    |type                = lander
    |object              = [[Mars]]
-   |arrival_date        = {{start date|1997|07|04}} 16:56:55 [[Coordinated Universal Time|UTC]]<br/><small>({{Age in years, months and days|year=1997|month=07|day=04}} ago)</small>
+   |arrival_date        = {{start date|1997|07|04}} 16:56:55 UTC<br/><small>({{Age in years, months and days|year=1997|month=07|day=04}} ago)</small>
    |location            = [[Ares Vallis]], [[Chryse Planitia]], [[Mars]]<br>{{Coord|19|7|48|N|33|13|12|W|globe:mars|name=Sojourner rover (Mars Pathfinder)}}
    |distance            =
-  }}
+}}
 | trans_band            = X-Band with high-gain antenna
 | trans_bandwidth       = 6 kb/s to 70m [[Deep Space Network]], 250 b/s to surface command<ref name=fact-sheet>{{cite web|url=http://mars.jpl.nasa.gov/MPF/mpf/fact_sheet.html|title=Mars Pathfinder Fact Sheet|publisher=NASA/JPL|date=19 March 2005|accessdate=February 21, 2014}}</ref>
@@ Line 48: / Line 47: @@
 }}
-'''Mars Pathfinder''' ('''MESUR Pathfinder'''<ref name="NASA-Sojourner" /><ref>{{cite news |last=Sawyer |first=Kathy |newspaper=[[Washington Post]] |title=One Way or Another, Space Agency Will Hitch a Ride to Mars |date=November 13, 1993 |url=http://pqasb.pqarchiver.com/washingtonpost/access/72203158.html?FMT=ABS&FMTS=ABS:FT&date=Nov+13%2C+1993&author=Kathy+Sawyer&desc=One+Way+or+Another%2C+Space+Agency+Will+Hitch+a+Ride+to+Mars |accessdate=November 24, 2010}}</ref>) is an American [[robotic spacecraft]] that landed a base station with a [[rover (space exploration)|roving probe]] on [[Mars]] in 1997. It consisted of a [[Lander (spacecraft)|lander]], renamed the '''Carl Sagan Memorial Station''', and a lightweight (10.6&nbsp;kg/23&nbsp;lb) wheeled [[robot]]ic [[Mars rover]] named ''[[Sojourner (rover)|Sojourner]]'',<ref>{{cite web |url=http://mpfwww.jpl.nasa.gov/missions/past/pathfinder.html |title=Mars Pathfinder |work=NASA |accessdate=June 10, 2015}}</ref> which became the first rover to operate outside
+'''Mars Pathfinder''' ('''MESUR Pathfinder'''<ref name="NASA-Sojourner" /><ref>{{cite news |last=Sawyer |first=Kathy |newspaper=Washington Post |title=One Way or Another, Space Agency Will Hitch a Ride to Mars |date=November 13, 1993 |url=http://pqasb.pqarchiver.com/washingtonpost/access/72203158.html?FMT=ABS&FMTS=ABS:FT&date=Nov+13%2C+1993&author=Kathy+Sawyer&desc=One+Way+or+Another%2C+Space+Agency+Will+Hitch+a+Ride+to+Mars |accessdate=November 24, 2010}}</ref>) is an American [[robotic spacecraft]] that landed a base station with a [[rover (space exploration)|roving probe]] on [[Mars]] in 1997. It consisted of a [[Lander (spacecraft)|lander]], renamed the '''Carl Sagan Memorial Station''', and a lightweight (10.6&nbsp;kg/23&nbsp;lb) wheeled [[robot]]ic [[Mars rover]] named ''[[Sojourner (rover)|Sojourner]]'',<ref>{{cite web |url=http://mpfwww.jpl.nasa.gov/missions/past/pathfinder.html |title=Mars Pathfinder |work=NASA |accessdate=June 10, 2015}}</ref> which became the first rover to operate outside
 the Earth-Moon system.
 Launched on December 4, 1996 by [[NASA]] aboard a [[Delta II]] booster a month after the [[Mars Global Surveyor]] was launched, it landed on July 4, 1997 on [[Mars]]'s [[Ares Vallis]], in a region called [[Chryse Planitia]] in the [[Oxia Palus quadrangle]]. The [[lander (spacecraft)|lander]] then opened, exposing the rover which conducted many experiments on the Martian surface.
-The mission carried a series of scientific instruments to analyze the Martian [[Celestial body atmosphere|atmosphere]], [[climate]], geology and the composition of its [[rock (geology)|rocks]] and soil. It was the second project from NASA's [[Discovery Program]], which promotes the use of low-cost spacecraft and frequent launches under the motto "cheaper, faster and better" promoted by the then administrator, [[Daniel Goldin]]. The mission was directed by the [[Jet Propulsion Laboratory]] (JPL), a division of the [[California Institute of Technology]], responsible for NASA's [[Exploration of Mars|Mars Exploration Program]]. The project manager was JPL's [[Tony Spear]].
+The mission carried a series of scientific instruments to analyze the Martian [[Celestial body atmosphere|atmosphere]], [[climate]], geology and the composition of its [[rock (geology)|rocks]] and soil. It was the second project from NASA's [[Discovery Program]], which promotes the use of low-cost spacecraft and frequent launches under the motto "cheaper, faster and better" promoted by the then administrator, [[Daniel Goldin]]. The mission was directed by the [[Jet Propulsion Laboratory]] (JPL), a division of the California Institute of Technology, responsible for NASA's [[Exploration of Mars|Mars Exploration Program]]. The project manager was JPL's [[Tony Spear]].
-This mission was the first of a series of missions to Mars that included rovers, and was the first successful lander since the two ''[[Viking program|Vikings]]'' landed on the red planet in 1976. Although the [[Soviet Union]] successfully sent rovers to the Moon as part of the [[Lunokhod program]] in the 1970s, its attempts to use rovers in its [[Mars program]] failed.
+This mission was the first of a series of missions to Mars that included rovers, and was the first successful lander since the two ''[[Viking program|Vikings]]'' landed on the red planet in 1976. Although the Soviet Union successfully sent rovers to the Moon as part of the [[Lunokhod program]] in the 1970s, its attempts to use rovers in its [[Mars program]] failed.
 In addition to scientific objectives, the Mars Pathfinder mission was also a "proof-of-concept" for various technologies, such as [[airbag]]-mediated touchdown and automated obstacle avoidance, both later exploited by the [[Mars Exploration Rover]] mission. The Mars Pathfinder was also remarkable for its extremely low cost relative to other unmanned space missions to Mars. Originally, the mission was conceived as the first of the [[Mars Environmental Survey]] (MESUR) program.
@@ Line 65: / Line 64: @@
 ==Science experiments==
 [[File:Sojourner on Mars PIA01122.jpg|thumb|left|200px|''Sojourner'' rover on Mars on sol 22]]
-The Mars Pathfinder conducted different investigations on the Martian soil using three scientific instruments. The lander contained a [[stereo camera|stereoscopic camera]] with spatial filters on an expandable pole called Imager for Mars Pathfinder (IMP),<ref>{{Cite journal|title= The imager for Mars Pathfinder experiment|author1=Smith, P. H. |author2=Tomasko, M. G. |author3=Britt, D. |author4=Crowe, D. G. |author5=Reid, R. |author6=Keller, H. U. |author7=Thomas, N. |author8=Gliem, F. |author9=Rueffer, P. |author10=Sullivan, R. |author11=Greeley, R. |author12=Knudsen, J. M. |author13=Madsen, M. B. |author14=Gunnlaugsson, H. P. |author15=Hviid, S. F. |author16=Goetz, W. |author17=Soderblom, L. A. |author18=Gaddis, L. |author19=Kirk, R. |journal=[[Journal of Geophysical Research]] |volume= 102 |issue=E2 |pages=4003–4026 |date=1997 |doi=10.1029/96JE03568 |bibcode=1997JGR...102.4003S}}</ref><ref>{{Cite journal |title=Results from the Mars Pathfinder camera |author1=Smith P. H. |author2=Bell J. F. |author3=Bridges N. T. |journal=[[Science (journal)|Science]] |volume= 278|issue=5344 |pages=1758–1765|date=1997| doi=10.1126/science.278.5344.1758|pmid=9388170|bibcode = 1997Sci...278.1758S }}</ref> and the Atmospheric Structure Instrument/Meteorology Package (ASI/MET)<ref>{{Cite journal| title= The Mars Pathfinder atmospheric structure investigation meteorology (ASI/MET) experiment|author1=Schofield J. T. |author2=Barnes J. R. |author3=Crisp D. |author4=Haberle R. M. |author5=Larsen S. |author6=Magalhaes J. A. |author7=Murphy J. R. |author8=Seiff A. |author9=Wilson G. |journal= Science|volume= 278|issue=5344|pages= 1752–1758|date= 1997| doi= 10.1126/science.278.5344.1752| pmid= 9388169|bibcode = 1997Sci...278.1752S }}</ref> which acts as a Mars meteorological station, collecting data about pressure, temperature, and winds. The MET structure included three [[windsock]]s mounted at three heights on a pole, the topmost at about one meter (yard) and generally registered winds from the West.<ref>{{cite web |url= http://mars.jpl.nasa.gov/MPF/science/windsocks.html |title=Windsocks on Mars |work=JPL/NASA Mars Pathfinder |year=2005 |accessdate=June 10, 2015}}</ref>
+The Mars Pathfinder conducted different investigations on the Martian soil using three scientific instruments. The lander contained a [[stereo camera|stereoscopic camera]] with spatial filters on an expandable pole called Imager for Mars Pathfinder (IMP),<ref>{{Cite journal|title= The imager for Mars Pathfinder experiment|author1=Smith, P. H. |author2=Tomasko, M. G. |author3=Britt, D. |author4=Crowe, D. G. |author5=Reid, R. |author6=Keller, H. U. |author7=Thomas, N. |author8=Gliem, F. |author9=Rueffer, P. |author10=Sullivan, R. |author11=Greeley, R. |author12=Knudsen, J. M. |author13=Madsen, M. B. |author14=Gunnlaugsson, H. P. |author15=Hviid, S. F. |author16=Goetz, W. |author17=Soderblom, L. A. |author18=Gaddis, L. |author19=Kirk, R. |journal=[[Journal of Geophysical Research]] |volume= 102 |issue=E2 |pages=4003–4026 |date=1997 |doi=10.1029/96JE03568 |bibcode=1997JGR...102.4003S}}</ref><ref>{{Cite journal |title=Results from the Mars Pathfinder camera |author1=Smith P. H. |author2=Bell J. F. |author3=Bridges N. T. |journal=Science |volume= 278|issue=5344 |pages=1758–1765|date=1997| doi=10.1126/science.278.5344.1758|pmid=9388170|bibcode = 1997Sci...278.1758S}}</ref> and the Atmospheric Structure Instrument/Meteorology Package (ASI/MET)<ref>{{Cite journal| title= The Mars Pathfinder atmospheric structure investigation meteorology (ASI/MET) experiment|author1=Schofield J. T. |author2=Barnes J. R. |author3=Crisp D. |author4=Haberle R. M. |author5=Larsen S. |author6=Magalhaes J. A. |author7=Murphy J. R. |author8=Seiff A. |author9=Wilson G. |journal= Science|volume= 278|issue=5344|pages= 1752–1758|date= 1997| doi= 10.1126/science.278.5344.1752| pmid= 9388169|bibcode = 1997Sci...278.1752S}}</ref> which acts as a Mars meteorological station, collecting data about pressure, temperature, and winds. The MET structure included three [[windsock]]s mounted at three heights on a pole, the topmost at about one meter (yard) and generally registered winds from the West.<ref>{{cite web |url= http://mars.jpl.nasa.gov/MPF/science/windsocks.html |title=Windsocks on Mars |work=JPL/NASA Mars Pathfinder |year=2005 |accessdate=June 10, 2015}}</ref>
 The ''[[Sojourner (rover)|Sojourner]]'' rover had an Alpha Proton X-ray Spectrometer ([[APXS]]),<ref>{{Cite journal |title=Determination of the chemical composition of Martian soil and rocks: The alpha proton X ray spectrometer |author1=R. Rieder |author2=H. Wänke |author3=T. Economou |author4=A. Turkevich |journal=  J. Geophysical Research |date= 1997 |volume= 102 |pages=4027–4044 |doi=10.1029/96JE03918 |bibcode=1997JGR...102.4027R}}</ref> which was used to analyze the components of the rocks and soil. The rover also had two black-and-white cameras and a color one. These instruments could investigate the geology of the Martian surface from just a few millimeters to many hundreds of meters, the [[geochemistry]] and evolutionary history of the rocks and surface, the [[magnetic]] and [[mechanics|mechanical]] properties of the land, as well as the magnetic properties of the dust, atmosphere and the [[rotation]]al and [[orbit]]al dynamics of the planet.
 [[File:h rover-comp wheels 02.jpg|thumb|right|200px|Wheel size comparison: ''Sojourner'', [[Mars Exploration Rover]], [[Mars Science Laboratory]]]]
-Three [[navcam|navigation cameras]] were on board the rover: Two black and white 0.3-[[megapixel]] cameras were located on the front (768 horizontal [[pixel]]s × 484 vertical pixels configured in 4×4+100 pixel blocks), coupled with five [[laser]] stripe projectors, which enabled [[stereoscopy|stereoscopic]] images to be taken along with measurements for hazard detection on the rover's path. A third camera with the same resolution but taking color images was located on the back, near the APXS, and rotated by 90°. It provided images of the APXS's target area and the rover's tracks on the ground. The pixels of this colour camera were arranged in such a way, that out of the 16 pixel of a 4×4 pixel block, 12 pixel were sensitive to green, 2 pixel to red and 2 pixel were sensitive to [[infrared]] as well as blue. As all cameras had [[camera lens|lenses]] made out of [[zinc selenide]], which blocks light below a [[wavelength]] of 500&nbsp;nm, no blue light actually reached these "blue/infrared" pixels, which therefore recorded only infrared.
+Three [[navcam|navigation cameras]] were on board the rover: Two black and white 0.3-[[megapixel]] cameras were located on the front (768 horizontal [[pixel]]s × 484 vertical pixels configured in 4×4+100 pixel blocks), coupled with five laser stripe projectors, which enabled [[stereoscopy|stereoscopic]] images to be taken along with measurements for hazard detection on the rover's path. A third camera with the same resolution but taking color images was located on the back, near the APXS, and rotated by 90°. It provided images of the APXS's target area and the rover's tracks on the ground. The pixels of this colour camera were arranged in such a way, that out of the 16 pixel of a 4×4 pixel block, 12 pixel were sensitive to green, 2 pixel to red and 2 pixel were sensitive to infrared as well as blue. As all cameras had [[camera lens|lenses]] made out of [[zinc selenide]], which blocks light below a [[wavelength]] of 500&nbsp;nm, no blue light actually reached these "blue/infrared" pixels, which therefore recorded only infrared.
 All three cameras were [[Charge-coupled device|CCDs]] manufactured by [[Eastman Kodak Company]], and were controlled by the rover's [[Central processing unit|CPU]]. They all had auto-exposure and capabilities for handling bad pixels, and the image parameters (exposure time, compression used, etc.) were included in the transmitted images as part of the [[image header]]. The rover could [[data compression|compress]] the front cameras' images using the [[block truncation coding]] (BTC) algorithm, but it could only do the same for the back camera's images if the colour information was discarded. The cameras' [[optical resolution]] was sufficient to resolve 0.6&nbsp;cm details across a 0.65&nbsp;m range.<ref name="sojcam" />
@@ Line 75: / Line 74: @@
 ===''Pathfinder'' lander===
 # Imager for Mars Pathfinder (IMP), (includes [[magnetometer]] and [[anemometer]])
-# [[Celestial body atmosphere|Atmospheric]] and [[Meteorology|meteorological]] sensors (ASI/MET)
+# [[Celestial body atmosphere|Atmospheric]] and meteorological sensors (ASI/MET)
 ===''Sojourner'' rover===
 {{Main |Sojourner (rover)}}
 # Imaging system (three cameras: front B&W stereo,<ref name="sojcam">{{cite web |url=http://pdsimg.jpl.nasa.gov/data/mpfr-m-rvrcam-2-edr-v1.0/mprv_0001/document/rcinst.htm |title=Rover Camera Instrument Description |work=NASA |accessdate=June 10, 2015}}</ref> 1 rear color)
-# [[Laser]] striper hazard detection system
+# Laser striper hazard detection system
-# Alpha Proton [[X-ray]] [[Spectrometer]] ([[Alpha particle X-Ray spectrometer|APXS]])
+# Alpha Proton X-ray [[Spectrometer]] ([[Alpha particle X-Ray spectrometer|APXS]])
 # Wheel Abrasion Experiment
 # [[Materials Adherence Experiment]]
@@ Line 87: / Line 86: @@
 ==Landing site==
-The landing site was an ancient flood plain in Mars's northern hemisphere called "[[Ares Vallis]]" ("the valley of Ares", the ancient Greek equivalent of the ancient Roman deity Mars) and is among the rockiest parts of Mars. Scientists chose it because they found it to be a relatively safe surface to land on and one that contained a wide variety of rocks deposited during a catastrophic flood. After the landing, at {{Coord|19.13|N|33.22|W|globe:Mars|display=inline,title}},<ref>{{cite web| url=http://mpfwww.jpl.nasa.gov/MPF/science/geology.html |title=Mars Pathfinder Science Results |work=NASA}}</ref> succeeded, the landing site received the name ''The [[Carl Sagan]] Memorial Station'' in honor of the [[astronomer]].
+The landing site was an ancient flood plain in Mars's northern hemisphere called "[[Ares Vallis]]" ("the valley of Ares", the ancient Greek equivalent of the ancient Roman deity Mars) and is among the rockiest parts of Mars. Scientists chose it because they found it to be a relatively safe surface to land on and one that contained a wide variety of rocks deposited during a catastrophic flood. After the landing, at {{Coord|19.13|N|33.22|W|globe:Mars|display=inline,title}},<ref>{{cite web| url=http://mpfwww.jpl.nasa.gov/MPF/science/geology.html |title=Mars Pathfinder Science Results |work=NASA}}</ref> succeeded, the landing site received the name ''The [[Carl Sagan]] Memorial Station'' in honor of the astronomer.
 {{Wide image|Mars pathfinder panorama large.jpg|1200px|Mars Pathfinder panorama of landing site taken by IMP}}
@@ Line 112: / Line 111: @@
 ===Sojourner deployment===
-The ''Sojourner'' rover exit from the lander occurred on Sol 2, after its landing on July 4, 1997. As the next sols progressed it approached some rocks, which the scientists named "[[Barnacle Bill (Mars)|Barnacle Bill]]", "[[Yogi Rock|Yogi]]", and "[[Scooby-Doo]]", after famous [[cartoon]] characters. The rover made measurements of the elements found in those rocks and in the martian soil, while the lander took pictures of the ''Sojourner'' and the surrounding terrain, in addition to making climate observations.
+The ''Sojourner'' rover exit from the lander occurred on Sol 2, after its landing on July 4, 1997. As the next sols progressed it approached some rocks, which the scientists named "[[Barnacle Bill (Mars)|Barnacle Bill]]", "[[Yogi Rock|Yogi]]", and "[[Scooby-Doo]]", after famous cartoon characters. The rover made measurements of the elements found in those rocks and in the martian soil, while the lander took pictures of the ''Sojourner'' and the surrounding terrain, in addition to making climate observations.
 The ''Sojourner'' is a six-wheeled 65&nbsp;cm long vehicle, 48&nbsp;cm wide, 30&nbsp;cm tall and weighing 10.5&nbsp;kg.<ref>{{Cite web |url=http://mepag.jpl.nasa.gov/meeting/mar-09/02_MEPAG_McCuistion_Mar_09.pdf |format=PDF |title=Mars – the search for life |date=March 4, 2009 |accessdate=March 28, 2009 |publisher=NASA}}</ref> Its maximum speed reached one centimeter per second. Sojourner travelled approximately 100 metres in total, never more than 12&nbsp;m from the Pathfinder station. During its 83 [[Timekeeping on Mars#Sols|sols]] of operation, it sent 550 photographs to Earth and analyzed the [[chemistry|chemical]] properties of 16 locations near the lander. (See also [[Rover (space exploration)|Space exploration rovers]])
@@ Line 118: / Line 117: @@
 ===Sojourner's rock analysis===
 [[File:Sojourner and Barnacle Bill.jpg|thumb|''Sojourner'' next to the rock [[Barnacle Bill (Mars)|Barnacle Bill]]]]
-The first analysis on a rock started on Sol 3 with Barnacle Bill. The ''[[APXS|Alpha Particle X-ray Spectrometer]]'' (APXS) was used to determine its composition, the spectrometer taking ten hours to make a full scan of the sample. It found all the elements except [[hydrogen]], which constitutes just 0.1 percent of the rock's or soil's mass.
+The first analysis on a rock started on Sol 3 with Barnacle Bill. The ''[[APXS|Alpha Particle X-ray Spectrometer]]'' (APXS) was used to determine its composition, the spectrometer taking ten hours to make a full scan of the sample. It found all the elements except hydrogen, which constitutes just 0.1 percent of the rock's or soil's mass.
-The APXS works by irradiating rocks and soil samples with [[alpha particle]]s ([[helium]] [[atomic nucleus|nuclei]], which consist of two [[proton]]s and two [[neutron]]s). The results indicated that "Barnacle Bill" is much like Earth's [[andesite]]s, confirming past [[volcano|volcanic]] activity.  The discovery of andesites shows that some Martian rocks have been remelted and reprocessed.  On Earth, Andesite forms when magma sits in pockets of rock while some of the iron and magnesium settle out.  Consequently, the final rock contains less iron and magnesiums and more silica.  Volcanic rocks are usually classified by comparing the relative amount of alkalis (Na<sub>2</sub>O and K<sub>2</sub>O) with the amount of silica (SiO<sub>2</sub>).  Andesite is different from the rocks found in meteorites that have come from Mars.<ref name="Golombek, M 1997"/><ref name="nssdc.gsfc.nasa.gov">{{cite web |url=http://nssdc.gsfc.nasa.gov/planetary/marspath/apxs.html |title=APXS Composition Results |work=NASA |accessdate=June 10, 2015}}</ref><ref name="Bruckner, J. 2001">{{cite journal |last1=Bruckner |first1=J. |first2=G. |last2=Dreibus |first3=R. |last3=Rieder |first4=H. |last4=Wanke |year=2001 |title=Revised Data of the Mars Pathfinder Alpha Proton X-ray spectrometer: Geochemical Behavior of Major and Minor Elements |journal=Lunar and Planetary Science XXXII}}</ref>
+The APXS works by irradiating rocks and soil samples with [[alpha particle]]s (helium [[atomic nucleus|nuclei]], which consist of two [[proton]]s and two [[neutron]]s). The results indicated that "Barnacle Bill" is much like Earth's [[andesite]]s, confirming past [[volcano|volcanic]] activity.  The discovery of andesites shows that some Martian rocks have been remelted and reprocessed.  On Earth, Andesite forms when magma sits in pockets of rock while some of the iron and magnesium settle out.  Consequently, the final rock contains less iron and magnesiums and more silica.  Volcanic rocks are usually classified by comparing the relative amount of alkalis (Na<sub>2</sub>O and K<sub>2</sub>O) with the amount of silica (SiO<sub>2</sub>).  Andesite is different from the rocks found in meteorites that have come from Mars.<ref name="Golombek, M 1997"/><ref name="nssdc.gsfc.nasa.gov">{{cite web |url=http://nssdc.gsfc.nasa.gov/planetary/marspath/apxs.html |title=APXS Composition Results |work=NASA |accessdate=June 10, 2015}}</ref><ref name="Bruckner, J. 2001">{{cite journal |last1=Bruckner |first1=J. |first2=G. |last2=Dreibus |first3=R. |last3=Rieder |first4=H. |last4=Wanke |year=2001 |title=Revised Data of the Mars Pathfinder Alpha Proton X-ray spectrometer: Geochemical Behavior of Major and Minor Elements |journal=Lunar and Planetary Science XXXII}}</ref>
-Analysis of the Yogi rock again using the APXS showed that it was a [[basalt]]ic rock, more primitive than Barnacle Bill. Yogi's shape and texture show that it was probably deposited there by a [[flood]].
+Analysis of the Yogi rock again using the APXS showed that it was a [[basalt]]ic rock, more primitive than Barnacle Bill. Yogi's shape and texture show that it was probably deposited there by a flood.
 Another rock, named Moe, was found to have certain marks on its surface, demonstrating erosion caused by the wind. Most rocks analyzed showed a high content of [[silicon]]. In another region known as Rock Garden, ''Sojourner'' encountered crescent moon-shaped dunes, which are similar to [[dunes|crescentic dunes]] on Earth.
@@ Line 132: / Line 131: @@
 {{See also|Comparison of embedded computer systems on board the Mars rovers}}
-The [[embedded system|embedded]] computer on board the ''Sojourner'' rover was based around the 2&nbsp;MHz<ref>{{cite web|url=http://mars.jpl.nasa.gov/MPF/rover/faqs_sojourner.html#cpu |title=Mars Pathfinder FAQs - Sojourner CPU |work=NASA |accessdate=June 10, 2015}}</ref> [[Intel 80C85]] [[Central processing unit|CPU]] with 512&nbsp;[[Kilobyte|KB]] of [[Random access memory|RAM]] and 176&nbsp;KB of [[flash memory]] [[solid state disk|solid-state]] [[Data storage device|storage]], running a [[cyclic executive]].<ref name="ieeecomputer">{{cite journal |first1=Max |last1=Bajracharya |first2=Mark W. |last2=Maimone |first3=Daniel |last3=Helmick |title=Autonomy for Mars rovers: past, present, and future |journal=[[Computer (journal)|Computer]] |publisher=[[IEEE Computer Society]] |date=December 2008 |volume=41 |number=12 |pages=44–50 |issn=0018-9162 |url=http://users.etown.edu/w/wunderjt/ITALY_2009/PUBLICATION_MARS_SPIRIT_ALL_PATH_PLANNING_JPL.pdf}}</ref>
+The [[embedded system|embedded]] computer on board the ''Sojourner'' rover was based around the 2&nbsp;MHz<ref>{{cite web|url=http://mars.jpl.nasa.gov/MPF/rover/faqs_sojourner.html#cpu |title=Mars Pathfinder FAQs - Sojourner CPU |work=NASA |accessdate=June 10, 2015}}</ref> [[Intel 80C85]] [[Central processing unit|CPU]] with 512&nbsp;KB of [[Random access memory|RAM]] and 176&nbsp;KB of [[flash memory]] [[solid state disk|solid-state]] [[Data storage device|storage]], running a [[cyclic executive]].<ref name="ieeecomputer">{{cite journal |first1=Max |last1=Bajracharya |first2=Mark W. |last2=Maimone |first3=Daniel |last3=Helmick |title=Autonomy for Mars rovers: past, present, and future |journal=[[Computer (journal)|Computer]] |publisher=[[IEEE Computer Society]] |date=December 2008 |volume=41 |number=12 |pages=44–50 |issn=0018-9162 |url=http://users.etown.edu/w/wunderjt/ITALY_2009/PUBLICATION_MARS_SPIRIT_ALL_PATH_PLANNING_JPL.pdf}}</ref>
-The computer of the "Pathfinder" lander was a [[IBM RAD6000|Radiation Hardened IBM Risc 6000]] Single Chip (Rad6000 SC) [[Central processing unit|CPU]] with 128&nbsp;MB of RAM and 6&nbsp;MB of [[EEPROM]]<ref>{{cite web | url=http://quest.arc.nasa.gov/mars/ask/about-mars-path/pathfinder_computer.txt | title="QUESTION: What type of computer is the Pathfinder utilizing? ..." (NASA Quest Q&A) | date=1997 | accessdate=July 21, 2015 | publisher=[[NASA]] }}</ref><ref>{{cite web | url=http://quest.arc.nasa.gov/mars/ask/about-rover/Why_to_use_a_80C85_microprocessor_in_Rover_.txt | title="QUESTION: When it was designed, why was only a single 80C85 CPU used? ..." (NASA Quest Q&A) | date=1997 | accessdate=July 21, 2015 | publisher=[[NASA]] }}</ref> and its [[operating system]] was [[VxWorks]].<ref name=Wind_River>{{cite web | url=http://www.windriver.com/news/press/pr.html?ID=314 | title=Wind River Powers Mars Exploration Rovers—Continues Legacy as Technology Provider for NASA's Space Exploration | date=June 6, 2003 | accessdate=August 28, 2009 | publisher=[[Wind River Systems]] }}</ref>
+The computer of the "Pathfinder" lander was a [[IBM RAD6000|Radiation Hardened IBM Risc 6000]] Single Chip (Rad6000 SC) [[Central processing unit|CPU]] with 128&nbsp;MB of RAM and 6&nbsp;MB of [[EEPROM]]<ref>{{cite web | url=http://quest.arc.nasa.gov/mars/ask/about-mars-path/pathfinder_computer.txt | title="QUESTION: What type of computer is the Pathfinder utilizing? ..." (NASA Quest Q&A) | date=1997 | accessdate=July 21, 2015 | publisher=[[NASA]]}}</ref><ref>{{cite web | url=http://quest.arc.nasa.gov/mars/ask/about-rover/Why_to_use_a_80C85_microprocessor_in_Rover_.txt | title="QUESTION: When it was designed, why was only a single 80C85 CPU used? ..." (NASA Quest Q&A) | date=1997 | accessdate=July 21, 2015 | publisher=[[NASA]]}}</ref> and its operating system was [[VxWorks]].<ref name=Wind_River>{{cite web | url=http://www.windriver.com/news/press/pr.html?ID=314 | title=Wind River Powers Mars Exploration Rovers—Continues Legacy as Technology Provider for NASA's Space Exploration | date=June 6, 2003 | accessdate=August 28, 2009 | publisher=[[Wind River Systems]]}}</ref>
 The mission was jeopardised by a [[Concurrent computing|concurrent]] software bug in the lander,<ref>Parallel sparking: Many chips make light work, Douglas Heaven, New Scientist magazine, issue 2930, 19 August 2013, p44. [http://www.newscientist.com/article/mg21929301.000-parallel-sparking-many-chips-make-light-work.html?page=2 Online (by subscription)]</ref> which had been found in preflight testing but was deemed a glitch and therefore given a low priority as it only occurred in certain unanticipated heavy-load conditions, and the focus was on verifying the entry and landing code. The problem, which was reproduced and corrected from Earth using a laboratory duplicate thanks to the logging and debugging functionality enabled in the flight software, was due to [[Reset (computing)|computer resets]] caused by [[priority inversion]]. No scientific or engineering data was lost after a computer reset, but all the following operations were interrupted until the next day.<ref>{{cite web |url= http://research.microsoft.com/en-us/um/people/mbj/Mars_Pathfinder/Authoritative_Account.html |title=What really happened on Mars? - Authoritative Account |first=Glenn E. |last=Reeves |work=Microsoft.com |date=December 15, 1997 |accessdate=10 June 2015}}</ref><ref>{{cite web |url= http://research.microsoft.com/en-us/um/people/mbj/Mars_Pathfinder/ |title=What really happened on Mars? |first=Michael B. |last=Jones |work=Microsoft.com |date=December 16, 1997 |accessdate=June 10, 2015}}</ref> Four resets occurred (on July 5, 10, 11 and 14) during the mission,<ref>{{cite web |url= http://www.oarval.org/missionsr2.htm| title= The Mars Pathfinder Mission Status Reports &mdash; Second Week|publisher = Office of the Flight Operations Manager &ndash; Mars Pathfinder Project}}</ref> before patching the software on July 21 to enable [[priority inheritance]].<ref>{{cite web |url= http://www.oarval.org/missionsr3.htm| title= The Mars Pathfinder Mission Status Reports &mdash; Third Week|publisher = Office of the Flight Operations Manager &ndash; Mars Pathfinder Project}}</ref>
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 The lander sent more than 2.3 billion bits of information including 16,500 pictures and made 8.5 million measurements of the [[atmospheric pressure]], temperature and wind speed.<ref name=jplpathfinder>{{cite web|url=http://www.nasa.gov/mission_pages/mars-pathfinder/|title=Mars Pathfinder and Sojourner|work=NASA |accessdate=June 10, 2015}}</ref>
-By taking multiple images of the sky at different distances from the Sun, scientists were able to determine that the size of the particles in the pink haze was about one [[micrometre]] in radius.  The color of some soils was similar to that of an iron oxyhydroxide phase which would support the theory of a warmer and wetter climate in the past.<ref>Smith, P. et al.  1997.  Results from the Mars Pathfinder Camera Science: 278.  1758–1765</ref> Pathfinder carried a series of magnets to examine the magnetic component of the dust. Eventually, all but one of the magnets developed a coating of dust.  Since the weakest magnet did not attract any soil, it was concluded that the airborne dust did not contain pure [[magnetite]] or just one type of [[maghemite]]. The dust probably was an aggregate possibly cemented with [[ferric oxide]] (Fe<sub>2</sub>O<sub>3</sub>).<ref>Hviid, S.  et al.  1997.  Magnetic Properties Experiments on the Mars Pathfinder Lander:  Preliminary Results.  Science:278.  1768–1770.</ref> Using much more sophisticated instruments, [[Spirit Rover|Mars Spirit Rover]] found that magnetite could explain the magnetic nature of the dust and soil on Mars.  Magnetite was found in the soil and that the most magnetic part of the soil was dark.  Magnetite is very dark.<ref>Bertelsen, P. et al.  2004.  Magnetic Properties Experiments on the Mars Exploration rover Spirit at Gusev Crater.  Science: 305. 827–829.</ref>
+By taking multiple images of the sky at different distances from the Sun, scientists were able to determine that the size of the particles in the pink haze was about one micrometre in radius.  The color of some soils was similar to that of an iron oxyhydroxide phase which would support the theory of a warmer and wetter climate in the past.<ref>Smith, P. et al.  1997.  Results from the Mars Pathfinder Camera Science: 278.  1758–1765</ref> Pathfinder carried a series of magnets to examine the magnetic component of the dust. Eventually, all but one of the magnets developed a coating of dust.  Since the weakest magnet did not attract any soil, it was concluded that the airborne dust did not contain pure [[magnetite]] or just one type of [[maghemite]]. The dust probably was an aggregate possibly cemented with [[ferric oxide]] (Fe<sub>2</sub>O<sub>3</sub>).<ref>Hviid, S.  et al.  1997.  Magnetic Properties Experiments on the Mars Pathfinder Lander:  Preliminary Results.  Science:278.  1768–1770.</ref> Using much more sophisticated instruments, [[Spirit Rover|Mars Spirit Rover]] found that magnetite could explain the magnetic nature of the dust and soil on Mars.  Magnetite was found in the soil and that the most magnetic part of the soil was dark.  Magnetite is very dark.<ref>Bertelsen, P. et al.  2004.  Magnetic Properties Experiments on the Mars Exploration rover Spirit at Gusev Crater.  Science: 305. 827–829.</ref>
 Using [[Doppler tracking]] and [[two-way ranging]], scientists added earlier measurements from the ''Viking'' landers to determine that the non-hydrostatic component of the polar [[moment of inertia]] is due to the [[Tharsis bulge]] and that the interior is not melted. The central metallic core is between 1300&nbsp;km and 2000&nbsp;km in radius.<ref name="Golombek, M 1997">Golombek, M. et al. 1997.  Overview of the Mars Pathfinder Mission and Assessment of Landing Site Predictions.  Science. Science: 278.  pp. 1743–1748</ref>
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 The on-board battery—designed to operate for one month—may have failed after repeated charging and discharging. The battery was used to heat the probe's electronics to slightly above the expected nighttime temperatures on Mars. With the failure of the battery, colder-than-normal temperatures may have caused vital parts to break, leading to loss of communications.<ref name=batteryfailure>{{cite web |url=http://news.sciencemag.org/sciencenow/1997/10/27-04.html |title=Mars Pathfinder Nearing Its End |work=sciencemag.org |accessdate=June 10, 2015}}</ref><ref name=nasafacts>[http://www.jpl.nasa.gov/news/fact_sheets/mpf.pdf NASA facts - Mars Pathfinder]</ref>
-After the landing, Pathfinder was renamed as the ''Sagan Memorial Station'' in honor of [[astronomy|astronomer]] and [[Planetology|planetologist]] [[Carl Sagan]]. The mission had exceeded its goals in the first month.
+After the landing, Pathfinder was renamed as the ''Sagan Memorial Station'' in honor of astronomer and [[Planetology|planetologist]] [[Carl Sagan]]. The mission had exceeded its goals in the first month.
 [[Mars Reconnaissance Orbiter]] spotted Pathfinder in January 2007 ''(left)''.<ref>{{cite news |url=http://www.newscientist.com/article/dn10945 |title=Mars probe may have spotted lost rover |date=January 12, 2007 |first=Maggie |last=McKee |work=[[New Scientist]]}}</ref><ref>{{cite web |url=http://www.nasa.gov/mission_pages/MRO/multimedia/pia09105.html |title=Mars Pathfinder Landing Site and Surroundings |work=NASA |accessdate=June 10, 2015}}</ref>
@@ Line 166: / Line 165: @@
 ==Honors==
 * In 1997, the Sojourner Team was awarded a JPL Award for Technical Excellence
-* On October 21, 1997, at the [[Geological Society of America]]'s annual meeting in [[Salt Lake City, Utah]], ''Sojourner'' was awarded honorary membership in the Planetary Geology Division of the society<ref>{{Cite journal|title=Division Activity at Recent Meetings |journal=Planetary Geology Division Newsletter |volume=16 |issue=1 |pages=1 |date=1997 |url=http://www.unb.ca/passc/GSA/Newsletters.img/formatted%20newsletter%201998.pdf |format=– <sup>[http://scholar.google.co.uk/scholar?hl=en&lr=&q=intitle%3ADivision+Activity+at+Recent+Meetings&as_publication=Planetary+Geology+Division+Newsletter&as_ylo=1997&as_yhi=1997&btnG=Search Scholar search]</sup> |deadurl=yes |archiveurl=http://web.archive.org/web/20110608004417/http://www.unb.ca/passc/GSA/Newsletters.img/formatted%20newsletter%201998.pdf |archivedate=June 8, 2011 }}</ref>
+* On October 21, 1997, at the [[Geological Society of America]]'s annual meeting in Salt Lake City, Utah, ''Sojourner'' was awarded honorary membership in the Planetary Geology Division of the society<ref>{{Cite journal|title=Division Activity at Recent Meetings |journal=Planetary Geology Division Newsletter |volume=16 |issue=1 |pages=1 |date=1997 |url=http://www.unb.ca/passc/GSA/Newsletters.img/formatted%20newsletter%201998.pdf |format=– <sup>[http://scholar.google.co.uk/scholar?hl=en&lr=&q=intitle%3ADivision+Activity+at+Recent+Meetings&as_publication=Planetary+Geology+Division+Newsletter&as_ylo=1997&as_yhi=1997&btnG=Search Scholar search]</sup> |deadurl=yes |archiveurl=http://web.archive.org/web/20110608004417/http://www.unb.ca/passc/GSA/Newsletters.img/formatted%20newsletter%201998.pdf |archivedate=June 8, 2011}}</ref>
 * In 2003, ''Sojourner'' was inducted into the [[Robot Hall of Fame]]
 ==Image map of Mars==
-The following [[image map]] of the [[Mars|planet Mars]] has [[embedded link]]s to [[geography|geographical features]] in addition to the noted [[Mars rover|Rover]] and [[Mars lander|Lander]] locations. Click on the features and you will be taken to the corresponding article pages. [[North]] is at the top; [[Elevations]]: red (higher), yellow (zero), blue (lower).
+The following [[image map]] of the [[Mars|planet Mars]] has [[embedded link]]s to geographical features in addition to the noted [[Mars rover|Rover]] and [[Mars lander|Lander]] locations. Click on the features and you will be taken to the corresponding article pages. North is at the top; [[Elevations]]: red (higher), yellow (zero), blue (lower).
 {{Mars map indicating landers}}
 {{clear}}
-== In popular culture ==
+==In popular culture==
-*In the novel ''[[The Martian (Andy Weir)|The Martian]]'' by [[Andy Weir]], the protagonist, who is stranded alone on Mars, travels to the long-dead ''Pathfinder'' site and returns it to his base in an attempt to communicate with Earth.  The character even notes the "Twin Peaks" as a landmark.<ref>{{cite book|last=Weir|first=Andy|title=[[The Martian (Andy Weir)|The Martian]]|year=2014|location=[[New York City|New York]]|publisher=[[Crown Publishers]]|isbn=978-0-8041-3902-1}}</ref> This scenario was featured in the [[The Martian (film)|2015 film adaptation]] of the novel.
+*In the novel ''[[The Martian (Andy Weir)|The Martian]]'' by [[Andy Weir]], the protagonist, who is stranded alone on Mars, travels to the long-dead ''Pathfinder'' site and returns it to his base in an attempt to communicate with Earth.  The character even notes the "Twin Peaks" as a landmark.<ref>{{cite book|last=Weir|first=Andy|title=[[The Martian (Andy Weir)|The Martian]]|year=2014|location=New York|publisher=[[Crown Publishers]]|isbn=978-0-8041-3902-1}}</ref> This scenario was featured in the [[The Martian (film)|2015 film adaptation]] of the novel.
 *In the 2000 film ''[[Red Planet (film)|Red Planet]]'', astronauts stranded on Mars make a makeshift radio from parts of the ''Pathfinder''. They use the radio to communicate with their spaceship.
 ==See also==
-{{Portal|Mars|Spaceflight}}
 {{Columns-list|2|
 * [[Atmospheric reentry]]
@@ Line 226: / Line 224: @@
 ==External links==
-{{Commons category}}
+{{Commons|Category:Mars Pathfinder}}
 * [http://mpfwww.jpl.nasa.gov/MPF/default.html Mars Pathfinder NASA/JPL Website]
 * [http://www.jpl.nasa.gov/news/news.php?feature=5583 Mars Pathfinder 360 View] (released February 26, 2016).
@@ Line 244: / Line 242: @@
 {{Discovery and New Frontiers program}}
 {{Mars spacecraft}}
-{{Mars}}
-{{Orbital launches in 1996}}
 {{Carl Sagan}}
+{{Wikipedia|Mars Pathfinder}}
-{{Authority control}}
-[[Category:Mars Pathfinder| ]]
+[[Category:Mars Pathfinder|Mars Pathfinder]]
 [[Category:1997 in science]]
 [[Category:1997 robots]]