On Mars, Perseverance measures the dust that clings to materials
· BehindLines newsroom
Pieces of spacesuit materials have been travelling on Perseverance since the rover left Earth. Today they make it possible to study the dust that sticks to surfaces on Mars. Research presented on 26 and 29 October by NASA and Washington University in St. Louis looks in particular at extremely small grains.
These samples have a history separate from the search for traces of life. Before the 2020 launch, the Jet Propulsion Laboratory explained that they would be used to study the effect of the Martian environment, including radiation, on these materials. They are mounted on the calibration target of SHERLOC, which is used to check that instrument's settings. Original JPL presentation.
The recent analysis uses PIXL, the rover's X-ray spectrometer, on its own target and on the SHERLOC samples. According to NASA, the estimated grain sizes go down to about 100 nanometres depending on the surface. NASA announcement.
According to WashU, Scott VanBommel, lead author of the paper, developed a method for estimating the size of each particle. The materials showed little visible wear at the time of the observations analysed, after 1,645 Martian days. That observation of their condition is not enough, however, to assess every problem that dust would pose to a crewed mission. University presentation of 29 October.
For co-author Abigail Knight, the electrostatic properties of Martian dust probably explain why it adheres more readily to certain surfaces. According to VanBommel, engineers will need to take these ultrafine particles into account when designing habitats, spacesuits and air filters. The question therefore concerns the materials, filters and procedures that would limit how much dust is carried into a habitat.
The rover provides measurements in the real environment, but no astronaut was exposed in this experiment. Assessing the risk to a person would also require knowing the quantity of dust and the length of contact. The result therefore prepares tests and engineering choices; it does not certify the safety of a spacesuit or a habitat.