An engineer who helped develop Tesla Glass told us why a big part of her job is destroying things
- Rosie Mottsmith is a staff engineer at Tesla.
- A former physicist who also once worked on organic farms, she recently helped develop the high-strength glass that went into the Tesla Semi.
- She and her team developed a special cannon to launch projectiles at the glass to test it.
Editors Note: Business Insider had the chance to speak with four Tesla employees from different parts of the company to learn more about their work. And what we discovered were some of the coolest jobs at Tesla. This is the second in the series. You can read about what a Tesla quality inspector does here.
Everybody knows that engineers build stuff. Bridges, buildings, airplanes, robots.
But engineers also destroy stuff, because they have to identify weaknesses. A weak bridge collapses into a river, a flimsy building teeters, a flawed aircraft falls from the sky, and a bad robot can't do its job.
At Tesla, staff engineer Rosie Mottsmith has an appetite for destruction. For months, she and a team of engineers fired various projectiles from a cannon of their own design at sheets of Tesla's innovative Armor Glass - glass designed to wrap around the cabin of the Tesla Semi that CEO Elon Musk revealed in spectacular fashion in Los Angeles in November.
It wasn't a job she ever imagined doing, even in her wildest dreams.
Originally a physicist, Mottsmith started out at the Bay Area's Lawrence Berkeley National Laboratory, trying, as she puts it without a trace of arrogance, to "make a new light source."
"Ten years from now, that might have led to new research, and 10 years from now that might lead to a new discovery that would lead to a drug that might help somebody," she recalls, sipping tea in a cafeteria at Tesla's headquarters in Palo Alto, California.
Physics research was too abstract for Mottsmith's tastes, so she ventured out into the real world and spent some time at a nonprofit, as an elementary school teacher, and as an organic farmer before heading to Stanford to get an advanced degree in materials science and engineering. She joined Tesla in 2014 as a reliability engineer and worked on both drivetrains - chiefly the dual-motor all-wheel-drive system - and Tesla Energy's Powerwall battery.
With a Model 3 on the way to her driveway to join her husband's Model S, she's "all in" with the company, she says.
"What's wonderful about Tesla is how motivated everybody is by the mission," she says. "Not always the easiest place to work - what helps you push through it is knowing that your work is potentially affecting the entire world."
Putting herself in the mind of a trucker
Mottsmith might think about glass the way most of us do, as a critical automotive component as well as an aesthetic element; the Tesla Semi features a stunning view of the road for a driver.
But Mottsmith, like most engineers - and unlike most nonengineers - also has a mind that's trained to operate behind the scenes, to peer around corners, to expect the unexpected. For her, the Semi's huge glass windshield is a vital safety feature and a way of keeping a trucker on the road. That understanding came from designing the experiments that entailed firing the cannon thousands of times - "We put on some Judas Priest and blew off stress," Mottsmith says - but also from spending a day on the road with working truck drivers.
"It's a hard job," she says. "Truckers are basically mechanics and handymen. If anything goes wrong, they have to fix it themselves. A lot of times people think about engineers as optimizing things, but true engineering is understanding how your product is going to be used. It doesn't matter what happens in the lab if that doesn't keep the trucker safe."
Mottsmith and her team hurled everything from rocks to shredded tires to tow-hitches at sheets of Tesla Glass, seeking to serve the requirements of truckers while preparing the Semi to face countless problems on the road both seen and unforeseen.
The Semi had to be game changing in many respects, from its rethinking of the traditional big-rig cab to its performance, designed to be far superior to that of diesel-powered trucks. According to Mottsmith, that produced challenges.
"Distinguishing between the impossible and very difficult can be a speed bump," she says. "But what enables our process is pushing things to the limit and not accepting 'no' unless it's dictated by physics."
Joining the revolution
Mottsmith travels between Northern California and Southern California for her job and says she "has no plans to go elsewhere." A typical day could find her in Palo Alto working to interpret data to "find out what all the destruction means," walking the assembly line at the factory in nearby Fremont, consulting with other engineers, or venturing down to the Los Angeles area to shoot cannons at Tesla Glass in the Tesla Design Studio at SpaceX's factory.
"It's great that I don't spend every single day destroying things," she says, adding with a twinkle that "destroying things is really satisfying."
Ultimately, participating in the Semi project has been an amazing experience, even though she is excited about whatever she winds up doing next at Tesla. "The Semi is something completely new - it's going to change everything," she says. "You can just feel it in your gut that will be revolutionary."