How Sierra Nevada Corporation was selected to build components for Perseverance

July 20, 2020

NASA’s Perseverance rover is about 10 feet long, 9 feet wide and 7 feet tall. It takes a lot of parts and components to create something that large that will also be experiencing extreme temperature ranges throughout the day.

Sierra Nevada Corporation (SNC) proudly designed, developed and built eight mechanisms to be included throughout the rover.

We spoke with Jonathan, a senior mechanical engineer at SNC who worked on the project to explain the steps it took to develop those mechanism. 

How did NASA choose Sierra Nevada Corporation (SNC) to design and build the mechanism that are being used on the rover?
We were initially awarded gearboxes for each mechanism. As that work progressed, NASA opened up the motors that drive each of the gearboxes for us to bid on as well. Our team’s performance on the gearboxes stood out and helped us to win the motor contract.

Did you have to pass any tests for NASA as you developed each mechanism?
Each mechanism had to complete one of three test programs depending on its end use: qualification testing to verify its design, acceptance testing for the flight models and reduced testing for the non-flight engineering models.

Qualification testing added stiffness & static loading, shock exposure, high temperature vacuum exposure, and a two times life test over temperature in order to verify the designs met all of the requirements. 

Acceptance testing included performance verification, random vibration and thermal cycling including performance verification over temperature. 

The percussion gearmotor underwent life testing at NASA’s Jet Propulsion Laboratory because their testing facilities were able to better replicate the unique vibration environment it will see on Mars.

We also performed developmental testing to reduce risk in strategic areas where we were pushing components beyond prior heritage operating parameters. It turns out operating a mechanism for a long life at -70°C is really hard, but in the end we were successful! 

Why was this such an interesting design challenge for you?
Whether it was extreme temperatures, long life, high torque or just how to put it all together, each mechanism had its own unique set of requirements that needed creative solutions. It’s great working at place like SNC where we get creative freedom as engineers to develop customized solutions for the customer!

What did this project mean to you?
This was the highest public profile project I have ever worked on in my career and involved a big investment of personal energy over the course of two years. To be able to tell my children and nieces and nephews I helped design and build something that’s drilling into rocks on another planet – that’s pretty neat!

Why is space exploration so important to you?
I’ve always been interested in space, since building model rockets with my Dad and going to Space Camp as a child. It’s very rewarding to see our work used to expand mankind’s collective knowledge of the universe.