Illustration of the Mars Perseverance Rover using its SuperCam instrument to laser zap a rock in order to check what its made of. Credit: NASA
If your name starts with “L” you will especially enjoy this story about the very first letter to be laser etched on Mars.
Every once in a while, we see animations where a Mars rover is driven in a pattern to make letters in the sand with its wheel tracks. The letters may define a silly expression, and the animations typically have aliens on the side, laughing or perplexing over the significance. In reality, making use of lasers on board Mars rovers has likewise made it possible to laser-mark graffiti on Martian rocks.
Nevertheless, as NASAs instruments are usually used strictly for science, I did not believe laser graffiti would ever be done. However naturally, individuals have actually believed about it. When I got to JPL for the landing of Curiosity in 2012, I was amazed to find that a person of our engineers in charge of establishing sequences for SuperCams predecessor had written a prolonged sequence that would utilize the laser to define the instruments name on the rock surface area. It was all in enjoyable– we never ever actually wasted our shots using that series. On Perseverance, we have actually discovered a factor to use laser marking.
In genuine life, the usage of lasers on board Mars rovers has actually likewise made it possible to laser-mark graffiti on Martian rocks.
When I showed up at JPL for the landing of Curiosity in 2012, I was amazed to discover that one of our engineers in charge of developing sequences for SuperCams predecessor had written a prolonged sequence that would use the laser to spell out the instruments name on the rock surface area. Mars Perseverance Sol 471– SuperCam Camera: Three dark laser pits in the shape of a slightly slanted letter “L” were produced in the rock surface of target “Pinefield Gap” (Sol 471) as a dry run for marking the surface area of a sample core. The SuperCam instrument produced the laser pits using 125 shots in each pit, and also took this image. JPL delivered several rocks of differing firmness to Los Alamos National Laboratory where they were marked with pits made with different numbers of laser shots.
Mars Perseverance Sol 471– SuperCam Camera: Three dark laser pits in the shape of a slightly tilted letter “L” were produced in the rock surface of target “Pinefield Gap” (Sol 471) as a dry run for marking the surface area of a sample core. The L mark is a way to preserve understanding of the rotational orientation of the rock after the core is cut from the very same area. The original orientation of the surface area of the core will work to comprehend the original instructions of magnetic domains in the samples after they are brought back to Earth. The L is 2.5 mm tall by 1.0 mm long (0.1″ x 0.04″). The SuperCam instrument produced the laser pits utilizing 125 shots in each pit, and also took this image. Credit: NASA/JPL-Caltech/LANL/ CNES/IRAP.
About two years ago I received a call from Professor Ben Weiss from the Massachusetts Institute of Technology (MIT) asking about SuperCams laser marking abilities. In terrestrial rocks, this is the study of the magnetism caused by the Earths magnetic field at the time of the rocks development. Suffice it to say that we would enjoy to use the samples returned from the Perseverance mission to fill in that knowledge space.
To do that, for each Mars rock core sample that is returned, we need to know its original orientation in the world. If the surface areas of those core samples have easily identifiable features, thats no problem. That has actually held true with the cores collected up until now. If the surface is fine-grained, there might be absolutely nothing to distinguish its rotational orientation. Because case, we need to make synthetic markings on the surface.
Mars Perseverance Sol 498– Right Mastcam-Z Camera: Image taken by the Mastcam-Z ideal camera handled Sol 498 showing the 2 drill holes and abrasion spot on the Skinner Ridge rock surface area. Credit: NASA/JPL-Caltech/ASU.
We dont have a dark marker pen offered, however we do have a pulsed laser on the SuperCam. So Bens call to my lab a number of years ago got us thinking of how to mark the sample cores, and we began some tests. JPL delivered a number of rocks of differing hardness to Los Alamos National Laboratory where they were marked with pits made with various numbers of laser shots. The rocks were sent back to JPL for subsequent coring.
The SuperCam team was asked to be all set to mark a rock for coring with simply a couple of days of notification. The fundamental principle is to understand the rotational orientation of the core after it has actually been gotten rid of from the rock and positioned in the sample tube. Wanting to be most effective, we decided to use the easiest such pattern, consisting of 3 points (or laser pits) with unequal range in between them, like a capital letter “L.”.
SuperCam typically carries out line scans (a single row) or grid patterns. To produce the “L” shape, we took a 2 × 2 grid pattern and got rid of one point from the sequence, so the laser just made three pits. Utilizing 125 laser shots per pit, the result is displayed in the image of the “Pinefield Gap” target. Test cores are 13 mm (0.5″) in size, so the L patterns must fit well on their top surfaces. With the dry run successful, we are prepared to use the treatment to mark future samples.
Over the last week, the Perseverance rover finished its second of two samples from Jezero craters delta formation, from the Skinner Ridge block at Hogwallow Flats. Over the weekend Perseverance drove about 25 meters to Wildcat Ridge, situated slightly lower in Hogwallow, for more expedition.
Written by Roger Wiens, Principal Investigator, SuperCam/ Co-Investigator, SHERLOC instrument at Purdue University.