Posted on : Sunday 8th March 2020 04:41 AM
Last month, engineers at NASA’s Jet Propulsion Laboratory wrapped up the installation of the Mars 2020 rover’s 2.1-meter-long robot arm. This is the most mighty arm ever installed on a Mars rover. Even though the Mars 2020 rover shares much of its design with Curiosity, the new arm was redesigned to be able to do much more complicated science, drilling into rocks to collect samples that can be retained for later recovery.
JPL is well recognized for creating robots that do fantastic work in truly distant and hostile environments. The Opportunity Mars rover, to name just one example, had a 90-day planned mission but stayed operational for 5,498 days in a robot unfriendly place full of dust and wild temperature swings where even the most basic maintenance or repair is utterly impossible. (Its twin rover, Spirit, operated for 2,269 days.)
To learn more about the process behind building robotic systems that are able of feats like these, we talked with Matt Robinson, one of the engineers who designed the Mars 2020 rover’s new robot arm.
The Mars 2020 rover (which will be officially named through a public contest which opens this fall) is planned to launch in July of 2020, landing in Jezero Crater on February 18, 2021. The overall design is similar to the Mars Science Laboratory (MSL) rover, named Curiosity, which has been exploring Gale Crater on Mars since August 2012, except Mars 2020 will be a bit bigger and capable of performing even more amazing science. It will outweigh Curiosity by about 150 kilograms, but it’s commonly about the same size, and uses the same means of radioisotope thermoelectric generator for power. Upgraded aluminum wheels will be more sturdy than Curiosity’s wheels, which have suffered significant wear. Mars 2020 will land on Mars in the same way that Curiosity did, with a mildly insane descent to the surface from a rocket-powered hovering “skycrane.”
Mars 2020 very steps it up when it comes to science. The most worthwhile new capability (besides serving as the base station for a highly experimental autonomous helicopter) is that the rover will be able to take surface samples of rock and soil, put them into tubes, seal the tubes up, and then cache the tubes on the surface for later retrieval (and potentially return to Earth for analysis). Accumulating the samples is the job of a drill on the end of the robot arm that can be geared up with a wide array of interchangeable bits, but the arm holds a number of other tools as well. A “turret” can swap between the drill, a mineral identification sensor suite called SHERLOC, and an X-ray spectrometer and camera called PIXL. Fundamentally, most of Mars 2020’s science work is going to depend on the arm and the hardware that it holds, both in terms of close-up surface examinations and collecting samples for caching.
Matt Robinson is the Deputy Delivery Manager for the Sample Caching System on the Mars 2020 rover, which insures the robotic arm itself, the drill at the end of the arm, and the sample caching system within the body of the rover that manages the samples. Robinson has been at JPL since 2001, and he’s worked on the Mars Phoenix Lander mission as the robotic arm flight software developer and robotic arm test and operations engineer, as well as on Curiosity as the robotic arm test and procedures lead engineer.
The way that I look at it is, when you’re constructing an arm that’s going to go to another planet earth, all the things that could go wrong… You have to build something that’s robust and that can endure all that. It’s not that we’re trying to overdesign arms so that they’ll end up lasting much, much longer, it’s that, given all the things that you can come across within a fairly unknown environment, and the level of robustness of the design you have to apply, it just so happens we end up with designs that end up lasting a lot longer than they do. Which is great, but we’re not held to that, although we’re very happy when we see them last that long. Without any calibration, without any maintenance, exactly, it’s amazing. They show their wear over time, but they still operate, it’s super exciting, it’s very motivational to see.
This article is originally posted on IEEESPECTRUM.com