Mars Pathfinder rover

The Mars Pathfinder rover (flight spare) pictured with one of the Mars Exploration Rovers (MER) during assembly. 

The Mars Pathfinder rover carried an Alpha Proton X-ray Spectrometer (APXS), and the two Mars Exploration Rovers (MER - Spirit and Opportunity) carried Alpha Particle X-ray Spectrometers (also called APXS, but in this case more precise versions of the Pathfinder instrument, though without the ability to monitor protons for light element analyses). These instruments contained radioactive curium sources (Fig. 13.16) whose decay produced a-particles, which irradiated target rocks and soils. The resulting characteristic X-rays provided measurements of major and minor element abundances. The MER rovers also carried Mossbauer spectrometers, which yielded information on iron oxidation state. 

Aerogel is a special materials with extreme micron porosity. It consists of separate particles of several nanometers, interconnected in a high-porosity branched structure. It was made on the basis of gel consisting of colloid silicone, the structural parts of which are filled with solvents. Aerogel is subjected to high temperature under pressure which rises to the critical point it is very strong and easily endures stress both at lift-off and in the space environment. This material has already been tried in space by Spacelab II and Eureca shuttles, as well as by the American Mars Pathfinder Rover. 

Viking landers carried out Rutherford back-scattering and X-ray fluorescence (XRF) analyses of soils at two sites (Clark et al., 1982). Rocks and soils were analyzed by an alpha-proton X-ray spectrometer (APXS) on the Mars Pathfinder rover (Rieder et al., 1997) (Figure 1). Early APXS analyses (Rieder et al., 1997 McSween... 

Figure 1 Mars Pathfinder rover performing an APXS analysis of a rock (Barnacle Bill).

It is obvious from these experiments that the absorption spectrum of the Martian red surface can be simulated reasonably well by a non-unique variety of Fe rich phases or their mixtures as can the weak magnetism, so that a positive identification will probably only be possible, following further in situ analyses and/or sample return and analysis in the lab.Two Mars Exploration Rovers (MERs) are due to arrive at Mars in 2004 and will attempt to analyze rocks and soils on the surface using several small spectrometers, including PanCAM (an extended visible region spectrometer), MiniTES (a thermal emission spectrometer), APXS (alpha proton X-ray spectrometer measuring the major elements), Mossbauer (run at current local temperature), as well as a 5-level magnet array similar to that on-board the Pathfinder Lander. 

The composition of Martian surface materials can be assessed using laboratory analyses of Martian meteorites, in situ APXS analyses from Mars Pathfinder and the Mars Exploration Rovers, and orbital geochemistry analyzed by GRS and derived from TES spectra. 

Alkalis versus silica diagram used for geochemical classification of volcanic rocks. Martian meteorites, Gusev crater rocks and soils analyzed by the Spirit rover, and Bounce Rock analyzed by the Opportunity rover generally plot in the field of basalts, as does the average Mars Odyssey GRS analysis. Compositions derived from TES spectra (Surface Types 1 and 2) and the Mars Pathfinder dust-free rock plot in the basaltic andesite and andesite fields. After McSween et at. (2009). 

All Mars rovers to date have carried alpha-particle X-ray spectrometer (APXS) instruments for chemical analyses of rocks and soils (see Fig. 13.16). The source consists of radioactive curium, which decays with a short half-life to produce a-particles, which then irradiate the sample. Secondary X-rays characteristic of specific elements are then released and measured by a silicon drift detector. The Mars Pathfinder APXS also measured the backscattered a-particles, for detection of light elements, but the Mars Exploration Rovers measured only the X-rays. 

The next scheduled lander mission to Mars, Mars Exploration Rover, is due to attempt touchdown in January, 2004. Twin Mars Exploration Rovers will land at separate locations using the Pathfinder-tested airbag... 

Backshell—Upper shell of the Mars Pathfinder entry vehicle, enclosing the lander/rover vehicle along with the heat shield during the cruise and entry phases of the mission. Entry braking rockets are also mounted to the backshell. 

More complete and better data about the chemical composition of the Martian surface were obtained from the Mars Pathfinder s Soujourner Rover, which landed on the planet s surface on July 4, 1997. The chart on pages 119-121 contains data on three soil samples gathered from Mars on this mission (A-2, A-4, and A-5), as well as two Martian rocks, nicknamed "Barnacle Bill" (A-3) and... 

As discussed in Section 12Ci-3, the Al XS. or alpha proton X-ray spectrometer, has been an important experiment aboard all of the Mars exploration rovers. Journal articles provide details of the APXS experiments on the most recent missions in 2004 and compare the instrumentation and measurement strategies with those on board the Pathfinder mission of 1997.- ... 

Abstract NASA has used aerogel in several space exploration missions over the last two decades. Aerogel has been used as a hypervelocity particle capture medium (Stardust) and as thermal insulation for the Mars Pathfinder, Mars Exploration Rovers, and Mars Science Lander. Future applications of aerogel are also discussed and include the proposed use of aerogel as a sample collection medium to return upper atmosphere particles from Mars to earth and as thermal insulation in thermal-to-electric generators for future space missions and terrestrial waste-heat recovery technology. 

Later successful U.S. landers included the Mars Pathfinder lander/rover mission (which utilized air bags rather than retro-rockets during the last phase of its landing) and the Phoenix, which studied the geologic history of water on Mars, its involvement in Martian climate change, and the planet s past or future habitability. 

Materials. Multilayer textiles developed for the air bs s used in the Mars Pathfinder and Exploration Rovers are being used in Warwick Mills puncture-and impact-resistant TurtleSkin product line of metal flex armor (MEA) vests, which are comparable to rigid steel plates but far more comfortable. 

Nomex was and still is widely used in the U.S. space programs, for instance, in the form of airbags for the Mars-Pathfinder and Mars-Exploration-Rover missions. 

The 260 million Pathfinder and the Mars rovers are sending streams of data from the Martian surface back to Earth. Meanwhile, the International Space Station has been bedeviled by a seemingly endless stream of accidents. The Mir space station, brought back to Earth and crashed into the ocean after 15 years in 2001, had several incidents where lives were at great risk, including a fire and a collision with a docking ship. The greatest measurable achievements in space have been made by the unmanned robotic vehicles and instruments. 

On July 4, 1997, after a 7-month trip, the Pathfinder spacecraft landed on Mars and released a small robot rover called Sojourner. The weight of an objea on Mars is about 38% of the weight of the same object on Earth. 

Rover. Although Russian Mars 2 and Mars 3 descent modules brought rovers with them as early as 1971, no rover was successfully deployed on Mars until the U.S. Pathfinder mission of 1997 deployed its Sojourner rover. Able to travel about a half kilometer, or one-third of a mile from the lander, the Sojourner rover returned 550 photographs to Earth and the data from chemical analyses of sixteen locations on the Martian surface. 

The first successful landing on Mars was made by the two NASA Mars Viking 1 and 2 landers in 1976. Included in the payload were a gas chromatograph, mass spectrometer. X-ray fluorimeter, and three life detection instruments. Additional surface missions in 1997 (Pathfinder/Sojoumer Rover) and 2004 (Opportunity and... 

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