2018 Mars Global Dust Storm – Effects of Airborne Dust and Particle
Deposition on Mars Science Laboratory SAM (Sample Analysis at Mars)
Instrument Inlet Cover Actuator Temperatures
Abstract
The Sample Analysis at Mars (SAM) instrument is a suite of instruments
aboard the Mars Science Laboratory that landed on Mars in 2012. Recent
measurements of SAM inlet cover actuator temperatures during the 2018
Mars Global Dust Storm have shown less extreme, more benign effects that
are beneficial to mechanism performance. These in-situ measurements and
models developed from the current study can guide development of
actuators and mechanisms on future robotic and manned mission to Mars.
Deck-mounted actuators saw drastic, factor of two reduction in diurnal
temperature range from 70C to 35C. Maximum temperatures were reduced
from +10C to -10C due lower daytime air temperature and attenuation of
solar flux absorbed by the actuator body due to increased opacity.
Minimum temperatures increased from -60C to -45C due to warmer
night-time air temperatures and an enhanced downwelling atmospheric
radiation at the surface also caused by dust in the air. Another
demonstration of the effects of the dust storm on inlet cover actuator
temperature is the linear relation of optical depth plotted against
logarithmic diurnal temperature range. Air-fall dust deposition on the
white rover deck during the dust storm is indicated by scatter on this
linear trend. Other constantly-monitored SAM temperatures include
sensors on a second actuator that also shows the effects discussed above
and two sensors mounted internally to SAM with less pronounced effects.
In this work we will present an overview of the dust storm effects
superimposed on the seasonal variation of actuator and other SAM
temperatures.