Testing terrestrial rocks to help NASA’s Mars Perseverance rover run on Mars

Rubion Rock Testing: Engineers working with NASA’s Perseverance Mars rover have created this test area in the JPL to practice drilling for loose rock using a duplicate rover’s drill bit. The first Perseverance sample crumbled to powder rather than remained intact, prompting a test campaign. Credit: NASA / JPL-Caltech

Using carefully selected terrestrial rocks, engineers are trying to figure out how to work with crumbly rocks similar to the one the rover encountered during the first sampling attempt.

Creating a well in a test rock

Creating a well in a test rock: NASA Jet Propulsion Laboratory engineers conducted tests on rocks like this to understand why the first Perseverance rover attempt resulted in a powder sample. A duplicate rover storm was trying to create cores from crumbly rock. Credit: NASA / JPL-Caltech

When[{” attribute=””>NASA’s Perseverance Mars rover tried to collect its first rock core sample last August, the outcome presented a puzzle for the mission team: The rover’s sample tube came up empty. But why?

Not long after, Perseverance successfully gathered a sample the size of a piece of chalk from a different rock. The team concluded that the first rock they had chosen was so crumbly that the rover’s percussive drill likely pulverized it.

But engineers at NASA’s Jet Propulsion Laboratory in Southern California, which manages the mission, want to understand why that first sample, nicknamed “Roubion,” turned to dust. The mission’s scientists and engineers had run extensive test campaigns on dozens of rock types prior to launch, but they hadn’t seen any react exactly like Roubion.

So a new test campaign was started – one that would include a field trip, a duplicate of Perseverance’s drill, and JPL’s unique Extraterrestrial Materials Simulation Lab. Answers remain elusive, but here’s a closer look at the process.

How does a spaceship fight dust storms on Mars? Get the latest information on the rest of NASA’s Martian fleet using the Mars report. The new part is dedicated to the recent dust storm on the Red Planet. See how the agency’s orbiters supported the InSight lander as its power dwindled during the January event. Credits: NASA / JPL-Caltech / ASU / MSSS

Remembering Rubion

Restoring Roubion’s unique physical properties would be key to a test campaign.

“Of the rocks we saw, Rubion had the most evidence of interaction with water,” said Ken Farley of Caltech, a Perseverance project scientist. “That’s why it fell apart.”

Stones altered by water may be more prone to falling apart; they are also very valuable to Perseverance scholars. Water is one of the keys to life – at least on Earth – so Perseverance explores Lake Crater. Billions of years ago the Lake had a lake with river food, making it an ideal place to look for signs of ancient microscopic life. Perseverance collects samples that future missions can return to Earth for study in laboratories with powerful equipment too large to send to Mars.

Santa Margherita Ecological Reserve

Aerial photo of the Santa Margherita Ecological Reserve: An aerial drone filmed this view of members of NASA’s Perseverance rover at the Santa Margarita Environmental Reserve in Southern California when they were looking for crumbly rocks for a test campaign. Credit: NASA / JPL-Caltech

Field trip

To find Roubion’s backups, several members of the rover team received permission to hunt for rocks at the Santa Margarita Ecological Reserve, which is a two-hour drive from JPL. The team was looking for rocks that filled the geological sweet spot: weathered enough to look like Rubion, but not so fragile that they fell apart at the slightest touch. As a result, half a dozen stones were selected.

“It was very physical work,” said Louise Jandura of JPL, chief sampling and caching engineer who led the test campaign. “We beat with hammers and crowbars. The few stones were large enough for the five of us to hold on to the stretched canvas to tuck it into the bed of the truck. ”

Next step: testing in JPL. One of the places where this happens is the Extraterrestrial Materials Modeling Laboratory, a kind of service center that prepares materials for testing elsewhere in the JPL.

JPL Rock Hunters

JPL Rock Hunters: Members of the JPL team, who went in search of Mars-like rocks in the Santa Margherita Ecological Reserve, pose for a selfie. Left: Erin Dalshaug, Jonah Brockie, Louise Jandura, Ken Farley and Sarah Godix. Credit: NASA / JPL-Caltech

Super store rock

The low building is on a hillside above Mars Yard. The barrels in the front contain reddish dust called Mojave Mars Simulant, a special recipe for recreating the chaotic conditions in which rovers travel. Piles of stones – some of them strewn with drill holes – are scattered near the prohibitory industrial saw near the entrance. Behind is a concrete bunker with stones marked with names that sound like Mad Libs to geologists: Old Dutch Pemice, China Ranch Gypsum, Bishop Tuff.

“I like to say that we do handicraft selection and preparation of materials,” said Sarah Godix, a mechanical engineer who heads the lab. “Their testing is part of the production and part of the crazy science.”

Godix is ​​one of the people who chose the rocks for an excursion to the Santa Margherita Ecological Reserve. For testing on Rubion-like rocks, the Yearicks team worked with a construction drill, not a core drill, along with other tools, while the Yandura team used a duplicate Perseverance drill bit similar to flight. samples back and forth, testing them in different ways.

Close-up of a workout similar to perseverance

Close-up of a drill similar to Perseverance: This drill is a replica of the one aboard the Perseverance Mars rover. It was used in a test campaign to find out how crumbly rocks respond to drilling. Credit: NASA / JPL-Caltech

Put to the test

Janduri’s team held their flight drill a few millimeters at a time, stopping to see if the nucleus was still forming; if it fell apart, they would look at the variables that may be the cause. For example, engineers adjusted the speed of the drill and the weight on its bit. They also tried to drill the rock horizontally rather than vertically, in case the factor was a clump of debris.

It seemed that a new wrinkle appeared for each of their adjustments. One was that fragile specimens could still withstand a hammer drill. When the Jandura team reduced the force of the blow to avoid spraying the specimen, the drill was unable to penetrate the surface. But choosing a place that can withstand stronger percussion means choosing a place that is less likely to interact with water.

Perseverance has so far captured six specimens of heavily weathered rocks altered by water, and the team knows it is capable of much more. But experience with Rubion has prepared them for some of the extremes that Mars will throw at Persistence in the future. If they find more rocks such as Rubion, the extraterrestrial materials modeling lab will be ready with its menagerie of materials worthy of Mars.

More about the mission

The key goal of the Perseverance mission on Mars is astrobiology, including finding signs of ancient microbial life. The rover will characterize the geology of the planet and the climate of the past, pave the way for the study of the Red Planet by man and will be the first mission to collect and preserve Martian stone and regolith (broken rocks and dust).

Subsequent missions by NASA in collaboration with ESA (European Space Agency) will send a spacecraft to Mars to collect these sealed samples from the surface and return them to Earth for in-depth analysis.

The Mars 2020 Perseverance mission is part of NASA’s approach to studying the Moon on Mars, which includes Artemis’ mission to the Moon to help prepare humans for the study of the Red Planet.

The company JPL, which for NASA manages Caltech in Pasadena, California, built the rover Perseverance and manages it. Testing terrestrial rocks to help NASA’s Mars Perseverance rover run on Mars

Back to top button