Viking, mission to Mars

As mentioned earlier, analytical separation devices based on GC instrumentation have already been used in various space applications such as atmospheric probes and surface landers. Table 17.1 contains a summary of planetary exploration missions by NASA (both atmospheric probes and landers) where GC instrumentation has been used. The Viking mission to Mars contained two landers equipped with various scientific instruments for in situ analysis of the Martian atmosphere and soU. One of the analytical devices utiUzed a GC with one packed column equipped with a TCD to analyze the gases released by the soil (the Gas Exchange experiment GEX) after digestion of a nutrient liquid. The... 

The GC-MS instrument can be very compact and used in mobile equipment. A GC-MS device was used on the Viking Lander on the first Mars mission to search for organic compounds that would have provided evidence of life (none was detected). 

With the naked eye, ancient people could discern that the planet Mars is red, just as is the calx of iron ( rust )- Associating Mars—the god of war—with iron—the stuff of weapons, as well as with hlood—is intuitively reasonable. Late twentieth-century business executives wore red power ties to meetings. But in an almost too wonderful confirmation of ancient intuition, the findings of the NASA Viking Mission, which landed two spacecraft on Mars in 1976, indicated a red surface composed of oxides of iron eyeball chemical analysis by the Ancients at over 30 million miles—not bad ... 

RBS can provide absolute quantitative analysis of elemental composition with an accuracy of about 5%. It can provide depth-profile information from surface layers and thin films to a thickness of about 1 pm. In some cases, however, the high-energy beam can damage the surface. This is particularly a problem with insulating materials, such as polymers, alkali halides, and oxides. The Mars Pathfinder mission in 1997 contained an alpha proton X-ray spectrometer (APXS). In its RBS mode, the spectrometer bombarded samples with alpha particles and determined elemental composition via energy analysis of the backscattered particles. In addition to RBS, the APXS instrument was designed to carry out proton emission and particle-induced X-ray emission (PIXE) experiments. Soil and rock compositions were measured and compared to those from the earlier Viking mission. 

Many measurements were made to determine the content of water vapor in the atmosphere of Mars. Some examples are the MAWD (Mars Atmospheric Water Detector) on board of Viking 1 and Viking 2 orbiters or measurements made with Mars Global Surveyor Mission and Mars Express. Very often the IR band about 1.38 pm was used. Such measurements are important input factors for understanding the annual water cycle on Mars. For example Fedorova et al., 2010 [128] report on Viking observation of water vapor on Mars explaining some discrepancies of the results obtained by different instruments. 

For more details the reader is referred to Carr and Head, 2010 [59], There is evidence for recent water flows on Mars based on geologic maps from the Viking mission that indicate geologic and hydrologic activity extending into the Late Amazonian epoch especially in the Tharsis and Elysium area. Examples for such evidence are... 

D. Radiation Damage to Nitrate and the Viking Mars Mission... 

The Mars Pathfinder probe landed on Mars on July 4,1997. Pathfinder was second in the Discovery series of robotic spacecraft, which the United States National Aeronautics and Space Administration (NASA) began to develop in the mid 1990s. Costing an average of 150 million per project, the Discovery shift to faster, cheaper, less-ambitious probes was prompted by the catastrophic failure in 1993 of the 1-billion Mars Observer mission. Pathfinder was the third spacecraft ever to land successfully on Mars NASA s Viking I and Viking II spacecraft... 

---