UC Merced grad student, alumnus playing significant role in Mars 2020 mission

NASA’s fifth exploratory rover is heading for Mars to try and answer key questions about its potential for life.

Before the rover left Earth, current and former members of UC Merced’s Fundamental Tribology Lab conducted critical tests to provide key information for the mission’s success.

The Jet Propulsion Laboratory’s (JPL) Mars 2020 mission is part of NASA’s long-term Mars Exploration Program.

The Mars Perseverance rover launched from Cape Canaveral Air Force Station in Florida on Thursday. Once the rover arrives, its Sampling and Caching System will collect, package and store about 40 surface samples to possibly be returned to Earth to help NASA identify potential biological specimens.

System level tests on the rovers’ Adaptive Caching Assembly’s (ACA) mechanisms found sensitivities to friction in functional performance testing. Investigations focused on possible frictional increases due to unexpected behavior of dry film lubricants used on components within the ACA that can impact the ability to perform certain functions on Mars.

“In the extreme environments of space, it is absolutely critical to understand how these materials are going to interact,” said Duval Johnson, who leads the Applied Tribology Laboratory at JPL. “If our actuators don’t work as expected, if our lubricated materials don’t behave as they should, it could be a mission-critical type thing.”

JPL sought the expertise of UC Merced’s Fundamental Tribology lab, led by mechanical engineering Professor Ashlie Martini, to test the ACA’s dry film lubricants.

“The mission will rely on mechanical components that can’t be maintained. There won’t be people up there to repair parts once the rover arrives on Mars,” Martini said. “We have to ensure that all of the mechanical components on the Mars 2020 project are highly efficient and function as long as necessary in the Mars environment without maintenance.”

Johnson knows the tribology lab’s capabilities well because Martini was his faculty advisor from 2014 to 2018, while he was earning a doctoral degree in mechanical engineering from UC Merced.

Johnson sent samples made of the same materials as the rover components and coated with the same dry film lubricants to doctoral student Azhar Vellore to test using the lab’s tribometer — an instrument for measuring friction and wear. Such measurements quantify the resistance to motion, which determines how much energy it takes to move, and how much wear occurs, which enables prediction of how long moving parts will last.

“These samples are coated with the dry film lubricants that they plan to use in those components,” said Vellore, who is leading the project at UC Merced. “Based on the results I gather from testing, I can help NASA understand if these coatings can perform the way they want them to on Mars.”

Vellore began this investigation in December and wrapped up the testing in May, giving JPL time to implement the findings on the rover before it launched.

UC Merced Mechanical Engineering doctoral student Azhar Vellore has been critical in helping NASA’s Jet Propulsion Laboratory test dry film lubricants to resolve friction-related issues for its Mars 2020 mission to extract and store Martian rock and soil samples.

For Vellore, this project is a dream come true. “Since I was a kid, I’ve been incredibly interested in space,” he said.

The work he conducted for JPL is related to his dissertation research. Working in UC Merced’s Fundamental Tribology Lab, he uses new and different technologies to perform experiments and discover innovative surface engineering and lubrication techniques for energy-efficient design.

“I never knew I would be working on a project with NASA. I’ve come full circle,” he said.

Duval Johnson was born in Downey, Calif., and raised there until he moved to Mariposa at age 8. After high school, he served in the U.S. Army for three years, then ran an automotive business in Merced for three decades.

In 2009, 23 years after graduating from high school, he decided it was time to turn his physical work into mental work, so he took classes at Merced College.

“I took the skills I had with my hands and the knowledge I had for 30-plus years of working with mechanical components, and combined that with the theory,” he said.

Johnson earned his bachelor’s degree in mechanical engineering at UC Merced in 2014. “I was a non-traditional student,” he said. “I feel like they built UC Merced for me.”

He planned to go back to the automotive industry; however, the potential for research with Martini’s lab changed his perspective.

“Professor Martini had a collaborative project with Chevron that was exactly the kind of project that I needed,” Johnson said. “Grad school was a logical step.”

His doctoral dissertation research was in wet lubricants, but not related to aerospace.

He started working as a tribologist at the Jet Propulsion Lab in Pasadena in January 2018, before defending his thesis. Essentially everything that slides, moves, or rotates against another part comes through his lab for inspection. JPL has a host of missions it’s working on simultaneously. Johnson said his lab has worked on a dozen different missions over the past 12 months.

Johnson said anyone with an interest in mechanical engineering, should take a look at NASA centers like JPL.

This story was originally published August 3, 2020 at 7:32 AM.