The Miniature

Thermal Emission Spectrometer The Thermal Emission Spectrometer (TES) was an instrument on board Mars Global Surveyor. TES collected two types of data, hyperspectral thermal infrared data from 6 to 50 micrometres (μm) and bolometric visible-near infrared (0.3 to 2.9 μm) me ...

(Mini-TES) is an

infrared Infrared (IR; sometimes called infrared light) is electromagnetic radiation (EMR) with wavelengths longer than that of visible light but shorter than microwaves. The infrared spectral band begins with the waves that are just longer than those ...

spectrometer A spectrometer () is a scientific instrument used to separate and measure Spectrum, spectral components of a physical phenomenon. Spectrometer is a broad term often used to describe instruments that measure a continuous variable of a phenomeno ...

used for detecting the composition of a material (typically rocks) from a distance. By making its measurements in the

thermal infrared A thermal column (or thermal) is a rising mass of buoyant air, a convective current in the atmosphere, that transfers heat energy vertically. Thermals are created by the uneven heating of Earth's surface from solar radiation, and are an example ...

part of the

electromagnetic spectrum The electromagnetic spectrum is the full range of electromagnetic radiation, organized by frequency or wavelength. The spectrum is divided into separate bands, with different names for the electromagnetic waves within each band. From low to high ...

, it has the ability to penetrate through the dust coatings common to the Martian surface which is usually problematic for

remote sensing Remote sensing is the acquisition of information about an physical object, object or phenomenon without making physical contact with the object, in contrast to in situ or on-site observation. The term is applied especially to acquiring inform ...

observations. There is one on each of the two

Mars Exploration Rover NASA's Mars Exploration Rover (MER) mission was a robotic space mission involving two Mars rovers, ''Spirit (rover), Spirit'' and ''Opportunity (rover), Opportunity'', exploring the planet Mars. It began in 2003 with the launch of the two rove ...

Development

The Mini-TES was originally developed by

Raytheon Raytheon is a business unit of RTX Corporation and is a major U.S. defense contractor and industrial corporation with manufacturing concentrations in weapons and military and commercial electronics. Founded in 1922, it merged in 2020 with Unite ...

for the Department of Geological Sciences at

Arizona State University Arizona State University (Arizona State or ASU) is a public university, public research university in Tempe, Arizona, United States. Founded in 1885 as Territorial Normal School by the 13th Arizona Territorial Legislature, the university is o ...

. The Mini-TES is a miniaturized version of Raytheon's

Mars Global Surveyor ''Mars Global Surveyor'' (MGS) was an American Robotic spacecraft, robotic space probe developed by NASA's Jet Propulsion Laboratory. It launched November 1996 and collected data from 1997 to 2006. MGS was a global mapping mission that examined ...

(MGS) TES, built by Arizona State University and Raytheon SAS’ Santa Barbara Remote Sensing. The MGS TES data helped scientists choose landing sites for the Spirit and Opportunity Mars explorer rovers.

Martian soil

The Mini-TES is used for identifying promising rocks and soils for closer examination, and to determine the processes that formed Martian rocks. It measures the infrared radiation that the target rock or object emits in 167 different wavelengths, providing information about the target's composition. One particular goal is to search for minerals that were formed by the action of water, such as carbonates and clays. The instrument can also look skyward to provide temperature profiles of the Martian atmosphere and detect the abundance of dust and water vapor. The instrument is located inside the warm electronics box in the body of the rover - the mirror redirects radiation into the aperture from above. The Mini-TES instruments aboard the MERs Opportunity and Spirit were never expected to survive the cold Martian winter even if the rovers themselves survived. It was thought that a small

potassium bromide Potassium bromide ( K Br) is a salt, widely used as an anticonvulsant and a sedative in the late 19th and early 20th centuries, with over-the-counter use extending to 1975 in the US. Its action is due to the bromide ion ( sodium bromide is equa ...

(KBr)

beamsplitter A beam splitter or beamsplitter is an optical device that splits a beam of light into a transmitted and a reflected beam. It is a crucial part of many optical experimental and measurement systems, such as interferometers, also finding widespr ...

which was housed in an aluminium fitting would crack due to the mismatched

coefficient of thermal expansion Thermal expansion is the tendency of matter to increase in length, area, or volume, changing its size and density, in response to an increase in temperature (usually excluding phase transitions). Substances usually contract with decreasing temp ...

. This never happened however and the miniTES instrument on both rovers has survived several Martian winters, and the Spirit rover continues to periodically use the Mini-TES for remote sensing. (The miniTES on the Opportunity rover is not currently being used because of accumulated dust on the mirror following the 2007 dust storm). There are two other types of spectrometers mounted on the

rover Rover may refer to: People Name * Constance Rover (1910–2005), English historian * Jolanda de Rover (born 1963), Dutch swimmer * Rover Thomas (c. 1920–1998), Indigenous Australian artist Stage name * Rover (musician), French singer-songw ...

's arm which provide additional information about the composition when the rover is close enough to touch the object. Mini-Tes can work with

Pancam Each Pancam is one of two electronic stereo cameras on Mars Exploration Rovers ''Spirit'' and ''Opportunity''. It has a filter wheel assembly that enables it to view different wavelengths of light and the pair of Pancams are mounted beside tw ...

s to analyze surroundings. The Mini-TES weighs 2.1 kg (4.6 lb) of the total 185 kg (408 lb) for the whole rover.

References

External links

NASA JPL web-page stating purpose of Mini-TES

Technical academic publication on Mini-TES for Mars Exploration Rover

{{Mars Mars Exploration Rover mission Spectrometers Spacecraft instruments

Development

Martian soil

See also

References

External links