The Miniature Radio-Frequency instrument (Mini-RF) is a

synthetic aperture radar Synthetic-aperture radar (SAR) is a form of radar that is used to create two-dimensional images or three-dimensional reconstructions of objects, such as landscapes. SAR uses the motion of the radar antenna over a target region to provide fine ...

(SAR) instrument on the Lunar Reconnaissance Orbiter (LRO), which is currently in orbit around the

Moon The Moon is Earth's only natural satellite. It is the fifth largest satellite in the Solar System and the largest and most massive relative to its parent planet, with a diameter about one-quarter that of Earth (comparable to the width of ...

. It has a resolution of 30 m/pixel and two wavelength bands, a primary band at 12.6 cm and a secondary band at 4.2 cm. The original principal investigator of Mini-RF, Stewart Nozette, was arrested for espionage. Nozette was replaced by Ben Bussey, then of APL, the

Applied Physics Laboratory The Johns Hopkins University Applied Physics Laboratory (Applied Physics Laboratory, or APL) is a not-for-profit university-affiliated research center (UARC) in Howard County, Maryland. It is affiliated with Johns Hopkins University and emplo ...

where Mini-RF was assembled from components developed by a consortium of industry team members. Bussey accepted a position at NASA Headquarters and was replaced by the current principal investigator, Wes Patterson, also of APL. Previous

SAR SAR or Sar may refer to: Places * Sar (river), Galicia, Spain * Sar, Bahrain, a residential district * Sar, Iran (disambiguation), several places in Iran * Sar, Tibet, Tibet Autonomous Region of China * Šar Mountains, in southeastern Europe ...

instruments, such as the radar on the

Magellan Ferdinand Magellan ( or ; pt, Fernão de Magalhães, ; es, link=no, Fernando de Magallanes, ; 4 February 1480 – 27 April 1521) was a Portuguese explorer. He is best known for having planned and led the 1519 Spanish expedition to the East ...

mission to

Venus Venus is the second planet from the Sun. It is sometimes called Earth's "sister" or "twin" planet as it is almost as large and has a similar composition. As an interior planet to Earth, Venus (like Mercury) appears in Earth's sky never f ...

, were large, massive, power-hungry, and expensive. Intended as a demonstration of cheap, lightweight SAR technology, the Mini-RF instrument was designed in response to these concerns. Because it was a technology demonstration, Mini-RF is sometimes not included in lists of LRO's instruments. Radar is one of the few remote sensing tools capable of distinguishing water ice from other forms of water thought to be present of the Moon, such as hydrated minerals and water

adsorbed Adsorption is the adhesion of atoms, ions or molecules from a gas, liquid or dissolved solid to a surface. This process creates a film of the ''adsorbate'' on the surface of the ''adsorbent''. This process differs from absorption, in which a ...

onto the lunar surface. Although the LCROSS mission, which deliberately crashed a probe into the lunar surface to look for water, detected water in Cabeus Crater, Mini-RF did not detect the presence of thick deposits of water ice at the LCROSS impact site, however, the presence of less than 10 cm sized ice fragments could not be ruled out. In January, 2011, after completion of Mini-RF's primary mission objectives, NASA announced that the Mini-RF transmitter had suffered a critical failure. The receiver continues working, allowing occasional

bistatic radar Bistatic radar is a radar system comprising a transmitter and receiver that are separated by a distance comparable to the expected target distance. Conversely, a conventional radar in which the transmitter and receiver are co-located is called ...

measurements, where the radar signal is transmitted from the Earth, reflected off the Moon, and received by the Mini-RF.

References

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External links

Nasa Radar Tandem Searches For Ice On The Moon
Space synthetic aperture radar Lunar Reconnaissance Orbiter