Perseverance and Ingenuity landed on Mars almost exactly nine months ago. Over that time, both vehicles have already expanded our understanding of Mars, which will only increase over time as both vehicles will continue to conduct further experiments in the months and years to come. Perseverance is a rover based on Curiosity’s general design but with its own unique capabilities and some features Curiosity lacked. Ingenuity is the small helicopter that became the first human-built vehicle to fly on another world in the spring of 2021. Together, they fight crime do science.
We’ve rounded up the major discoveries made by both the rover and its copter buddy, as well as the technologies deployed on each.
Water, Soil, and the Search for Ancient Life
The principal mission of Perseverance and Ingenuity is to search for signs of ancient microbial life on Mars. In service to that goal, the Perseverance rover is loaded with imaging hardware, with which it can capture EM emissions from radio to hard UV. With these instruments, the rover is equipped to make on-the-spot judgments about what’s in the Martian regolith, rocks and atmosphere.
One such piece of imaging tech aboard Perseverance is the Scanning Habitable Environments with Raman & Luminescence for Organics & Chemicals (SHERLOC) instrument. SHERLOC is a boresighted resonance Raman and fluorescence spectrometer. To break that down a bit, it uses a UV laser to ping tiny bits of grit with photons of controlled wavelength, so we can analyze the photons thrown back off the sample to record their wavelength, polarization and other metadata. SHERLOC’s sidekick and “second eye,” WATSON, zooms out where SHERLOC zooms in: WATSON is a wide-angle camera used to document the spectrometer’s samples on the macro scale, just like a terrestrial photographer would try to get good macros of a subject with a DSLR.
Another instrument is the ground-penetrating Radar Imager for Mars’ Subsurface Experiment, known as RIMFAX. Radar waves are sensitive to the dielectric properties of the materials they survey, much like X-rays are sensitive to the absorptive properties of the materials they move through. RIMFAX will peer below the surface, as far as ten meters down into the regolith. Ultimately, this differential response allows us to make a 3D radar model of the subsurface stratigraphy of Mars, with a resolution or voxel size of ten centimeters. RIMFAX is there to characterize what lies below the landing site, but also to look for water ice hidden below the Martian surface where it might not have been sublimated away.
So far, perhaps the biggest discovery is that there is montmorillonite clay in the bottom of Jezero Crater. Clay is formed by the weathering of silicate rock in the presence of water. Even if there’s no detectable water ice in the deposit at the moment, clay is taken as a dead giveaway that water was present at one point. Evidence indicates that Jezero once held a crater lake, fed by a river whose delta opens up into a formation called Three Forks on the northwestern edge of the crater.
The Mars 2020 mission is looking for a lot of things, but one of the most important is water — and Jezero was full of it. Here on Earth, water is life: we think the very first amino acids stumbled into being from water full of organic building blocks. It’s believed that if there are traces of life on Mars, they’ll be where the water is, or at least where it was. (Martian lava tubes are another hopeful candidate, because of the traces of early life found in terrestrial lava tubes.) What’s more, we think that the delta is full of boulders. How did they get there? On Earth, rocks that size are only lifted and carried by sizeable floods. Images and data that RIMFAX, SHERLOC and WATSON gather will help us learn more about the history of Mars’ geological features, including just how wet ancient Mars might have been.
The total combined mass of Perseverance is just over a metric ton, with the chassis and instrumentation accounting for much of its weight. But Perseverance also carries an ultralight lab, in which it’s carrying out several side experiments to test how things behave in the Martian atmosphere, gravity, and radiation.
The star of the onboard material science show is the SHERLOC spectrometer’s calibration panel. Perseverance is carrying a plate inlaid with swatches of almost a dozen different materials, which SHERLOC will use to calibrate itself. One standout is a section of the polycarbonate material NASA uses in helmet visors. Confirming NASA’s awareness of their weapons-grade backronym habits, the polycarbonate is backed with a piece of opal glass bearing the fictional Sherlock’s street address. It doubles as a geocache for the public. You know, because we’re all just hanging out up there with our GoPros. (Please, please, let me live long enough for my response to the idea of a geocache on Mars is to change into sincere excitement at the ability to buy tickets.)
Also on the swatch plate are sections of certain ultra-high-performance flexible composite materials that we use to make the rest of the space suit. There’s a piece of Ortho-Fabric, a tiramisu of thermal/MMOD protective fabrics including Teflon, Kevlar, elastic Dacron for compression, and insulating Gore-Tex fleece. There’s also a piece of the Teflon-coated fiberglass fabric that shields the space suit’s gauntlets, and one of an upgraded version with a new dust coating. In between using them to calibrate its sensors, SHERLOC will periodically examine these swatches to see how they fare under constant exposure to the radiation on Mars’ surface, and the abrasion of its pervasive regolith dust.
While SHERLOC will stare unblinking at our own materials to see how they behave, MOXIE does its work by chemically changing matter it gathers onsite. It speaks to the Mars 2020 mission directive to gather data and test technologies that will help prepare for crewed missions to Mars. MOXIE, short for the Mars Oxygen In-Situ Resource Utilization Experiment instrument, is on Mars to see what it takes to make breathable amounts of oxygen out of Mars’ CO2 atmosphere. To do this, it draws in CO2 and pressurizes it to about one atmosphere. Then it electrolytically snaps the CO2 apart right at the cathode, leaving good old diatomic oxygen along with some carbon monoxide waste and some residual CO2.
MOXIE also serves the broader mission goal of using in-situ resources to answer in-situ needs. We are trying to explore, and potentially colonize, other planets. With our current best propulsion technology, the trip between Earth and Mars is still most easily described in months, not miles. It’s not plausible to ship bottled air to another planet as the sole source of everyone’s next breath — let alone to send bulk metal and concrete to space, when there’s a whole rocky planet underfoot to source our infrastructure from if we can. This is another entry in NASA’s long history of launching one mission along with hardware and intent to clear the way for the next.
After fifteen flights, Ingenuity is still going strong. It has now flown almost three kilometers, and now that it has finished its demo phase, it’s now engaging with Perseverance on their joint objective to pore over the Jezero Crater.
Ingenuity began its illustrious career on Mars as a technology demo for rotorcraft flight in a low-pressure environment, well below anything we encounter here on Earth. Mars’ atmosphere at surface level is about one and a half percent the density of Earth’s atmosphere at sea level. For comparison, the all-time helicopter altitude record on Earth reached the high-end of the passenger jet cruising altitude range, at approximately 42,500 feet. Even at that height the air on Earth is thirty times denser than Martian STP (Standard Temperature and Pressure). That makes piloting Ingenuity not just a first for aerodynamics, but a game-changer for offworld exploration as a whole.
Beyond getting into the record books, being able to fly around on Mars opens up a whole new class of possibilities for exploration. NASA is exploring new pathfinding and problem-solving methods and investing in off-world flight as part of its broad effort to get traction in the second great space race: the rush to commercialize low-earth orbit, and eventually to push the human sphere of influence outward into the greater solar system. Rovers are limited in their abilities by the fact that they have to contend with boulders, cliffs and crevasses, but NASA’s showing at DARPA’s 2021 rescue robot Olympics showed that the whole game changes if a robot can just use the Z axis to opt out of a terrain hazard altogether.
In addition to being the literal pilot project for powered flight on another planet, Ingenuity has two different cameras on board that enable high-res imaging of its environment. One is a downward-facing black-and-white camera for navigation, and the other is a forward-facing 13-megapixel color camera with stereoscopic imaging capabilities. The ability to photograph the landscape and terrain with this kind of resolution and fidelity is important all on its own for reasons of navigation: we need to know just where Ingenuity is, because it would be terribly unfortunate to perform unplanned lithobraking, what with the communications delay between Earth and Mars. But between those two cameras, Ingenuity is also capturing enough information to make a high-fidelity 3D map of the Martian landscape. Here’s one such image, in stereoscopic red and blue 3D:
Between the stereoscopic 3D and the repeated imaging of the terrain at different times on different sols, the amount of data produced can be used to map the Martian landscape right down to the individual rocks. Not so long ago, we weren’t even certain there was water anywhere else in the cosmos. Now we have a small population of robots on another planet, looking for traces of the emergence of life, and squinting down into the soil to see about the water we’re almost certain is there. This is valuable for legitimate, very serious, and very important scientific reasons. It’s also just incredibly cool that anyone with internet access can watch videos beamed to us from the surface of another planet.
Because of how it aced its initial objectives, Ingenuity’s documentary mission got an extension in 2021. Until they’re decommissioned, Ingenuity and Perseverance will both be working in concert with the other landers, rovers, and probes we have surveying Mars. Percy and the MRO are already checking each other’s work concerning the evidence of water on Mars. The rover’s samples, including the rock cores it has already collected, will be stored in caches on Mars. A future Mars mission in cooperation with the ESA (European Space Agency) will eventually retrieve them.
As time goes by and these results continue to roll in, we’ll update this article. If you have questions about what Ingenuity and Perseverance have been up to on Mars, or what we’ve learned from their tenure there, do let us know in the comments — we will address them in a future update.
Between now and then, if you want to get involved with Perseverance and Ingenuity yourself, you can! Anyone interested is formally invited to dive headfirst into Percy’s photostream as part of the open-access AI4Mars project, which labels the terrain the images depict in order to help train SPOC, the navigation AI that guides our robots on Mars. (No, Sulu was the navigator… but I digress.)
If you’re feeling extra creative, you could even take a shot at improving the algorithm under the hood of AI4Mars itself. The project is committed to making its data and code freely available, both libre and gratis. “If someone outside JPL creates an algorithm that works better than ours using our dataset, that’s great, too,” explained Hiro Ono, the JPL researcher and AI expert who led the development of AI4Mars. “It just makes it easier to make more discoveries.”