The Brilliance Behind the Plan to Land Curiosity on Mars

Adam Steltzner’s ingenious ideas were crucial to the most spectacular space mission of our time

(Composite Photo: NASA images; Photo illustration by Brian Smale)
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His father threw up his hands and declared his son would never be more than a ditch digger. For the next few years, Steltzner did his best to prove him right. After a short-lived stint at Boston’s Berklee College of Music, he came back to the Bay Area, playing bass guitar in various local rock bands. Yet he felt restless and dissatisfied. He recognized a disturbing tendency in himself: He would find an activity he enjoyed, but the moment it became serious and required a commitment, his interest would flag. “I awoke to the fact that I had been trained to wait around for my dad to die and inherit money,” he says. “I didn’t like the idea of that. I was hungry for real meaning.”

He found his path one crisp fall night after a gig, while driving home over the Golden Gate Bridge—a route that provided a fine view of the Orion constellation. He noticed that Orion was not in the same place as it had been earlier in the evening, and decided to learn more about why stars move. He enrolled in an astronomy course at a local community college and took a conceptual physics course as a prerequisite.

Unlike his father, whom Steltzner describes as an intellectual dilettante inhabiting a dreamy world of abstract ideas, Steltzner has a pragmatic bent. He gravitated toward physics, with its tangible rules about how the universe works, and engineering, the application of those rules to real-world problems. “Here was bedrock,” Steltzner says, and he threw himself into studying physics, math and engineering with discipline and purpose he hadn’t known he possessed. “I became a monk to learn that shit,” he says, shaving his hair into a buzz cut and subsisting on brown rice. “I looked at this like the savior of my life.”

Steltzner earned a bachelor’s degree in engineering from the University of California, Davis, and a master’s in applied mechanics from Caltech in 1991. He got his first job by cold-calling JPL scientists until someone agreed to hire him in the spacecraft structures and dynamics group. Eventually he earned his PhD in engineering mechanics from the University of Wisconsin-Madison, working for JPL remotely during the academic year.

“When I first met Adam he reminded me of Elvis Presley,” says Gentry Lee, chief engineer of JPL’s solar system exploration program. He immediately pegged Steltzner as a kindred spirit, “one of those creative people who don’t want to be told what to do and don’t necessarily want to follow the rules.” Lee believes that the lab challenges Steltzner without squelching his creativity, or his personal style. “I think a long time ago somebody realized that if you want to have a place famous for doing one-of-a-kind engineering feats, you better make sure that you don’t corral your people too tightly or they won’t be able to get the job done.”

For his part, Steltzner relishes the fact that the laboratory fosters a culture that “reveres the truth. There are no sacred cows, there is no dogmatism.” While many engineers prefer to gain mastery in a specialized area and then stick with what they know, Steltzner prefers what he calls “the steep end of the learning curve.” He says he carved out a niche for himself as the guy who relished the technical tasks and problems that didn’t have much precedent: “People started saying, ‘That’s weird, let’s give that to Adam and see what he can do with it.’”

He also turned out to have a gift for leadership, able to see how all the pieces fit together into a whole. So Steltzner was chosen to head the mechanical engineering team to develop the entry, descent and landing (EDL) system for Curiosity—a challenge because the sheer size of the rover meant that the methods developed for previous missions wouldn’t work.

Steltzner and his team brainstormed for three days in 2003. Earlier that year, NASA had launched two other Mars rovers—Spirit and Opportunity—each weighing 400 pounds. JPL engineers had encased the rovers in air bags, enabling them to land by bouncing on the planet’s surface and then rolling to a stop to dissipate impact. But that approach wouldn’t work for Curiosity, which weighs five times more than Spirit or Opportunity. The requisite air bags would be too heavy and therefore too costly to launch. The impact would also kick up a lot of dust, compromising both the rover and its sensitive instrumentation.

Then Steltzner and his team looked at the approach that was being devised for the 700-pound Mars Phoenix Lander, which was launched in 2007 to study the north pole of the planet. Thruster rockets gradually lowered the vehicle to the surface on top of a three-legged lander. But with the larger, heavier Curiosity on top, a three-legged lander would be too unstable. And it would require more powerful rockets than Phoenix’s, which might create craters in the soil, making it difficult for the rover to drive away after landing.

Eventually, the team arrived at a solution: a sky crane. “You stay attached, come out together and do all your flying, and then just above the surface, when you are in perfect vertical flight, do the deployment,” says Steltzner.

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