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Building on the success of the two rover geologists that arrived to Mars in January, 2004, NASA's next rover mission is
planned for the end of the decade. Twice as long and three times as heavy as Spirit and Opportunity, the Mars Science
Laboratory rover will collect Martian soil samples and rock cores and analyze them for organic compounds and
environmental conditions that could have supported microbial life now or in the past. MSL meteorological package is
called REMS (Rover environmental Monitoring Station). This is a scientific instrument designed to provide in situ,
near-surface measurements of Temperature (ground surface and atmosphere), Wind, Pressure, Water Vapour and
Ultraviolet Radiation (UV). UV observations at the surface will provide important information necessary to asses the
habitability of the near surface environment.
REMS UV sensor on MSL rover shall be pointing to the Martian sky. From the beginning, deposition of dust particles
on the sensor head was considered by NASA's science office a major concern. Such unpredictable phenomena may
attenuate the signal received by the optical sensor, and therefore must be considered by far the largest source of error in
the sensor.
We have studied the error introduced by Martian dust deposition, as well as by frost formation on REMS UV sensor.
Several error mitigation strategies such as the use of magnets where evaluated. Finally, a robotic dust wiper was
selected as error mitigation system. An optical sensor with a dust wiper was designed, constructed and pre-qualified for
MSL mission.
Several brushes where fabricated and tested as to maximize its efficiency with submicron particles dust. An
Engineering Model of the Sensor including the dust Wiper technology was fabricated and tested. The prototype was
subjected to an early qualification campaign under MSL project requirements. Technology performance and
qualification results are presented in this paper. The proposed Dust Wiper technology proves to be a simple, yet
effective solution to mitigate the error caused by dust on optical sensors or solar panels operating on dirty atmospheres.
Using a novel actuator technology based on SMA fibers, the solution represents a very small increase in Mass and a
major improvement in system performance. The actuator technology is now being considered for industrial sectors
where mass, reliability and cost reduction are key design goals.
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