Longhorns on Mars

At NASA’s Jet Propulsion Laboratory, a group of UT-educated scientists known as the “Texas mafia” is using robots to explore a new frontier.

Two and a half billion dollars of investment, the work of a thousand engineers, and eight years of planning and testing had come down to these seven minutes. It was midafternoon on Mars, a balmy 5 degrees F. Had an observer been watching from the plain below, he or it might have seen a spacecraft appear in the sky, hurtling toward the surface at 130,000 mph. Suddenly, the atmospheric drag triggered a parachute to open. Thus began a series of pre-programmed landing procedures, designed years in advance by the Mars Science Laboratory mission’s Entry, Descent, and Landing (EDL) team.

“It’s just nonstop,  a continuous seven minutes of if anything goes wrong, you’re done, you’re dead,” says Tom Rivellini, MS ’91. Rivellini, an engineer with the soul of an extreme sports athlete, helped design the “sky crane” maneuver that lowered the 2,000-pound Curiosity rover to the surface of Mars. On landing day, he was huddled with his team in the war room at the NASA Jet Propulsion Laboratory in Southern California. “It’s an incredible buildup of tension in those last minutes, and it was nerve-racking,” he says. “It was really bad.”

Mission Manager Mike Watkins, BA ’83, PhD ’89, was likewise watching nervously in the mission-control room as a Doppler signal came in from across the solar system. Normally as cool and confident as George Clooney in a well-fitted suit, Watkins was doing his best to keep his anxieties at bay. “We couldn’t talk to the vehicle, couldn’t fly it in any way,” he notes. “It had to be a sequence of automatic events.”

Curiosity would be by far the largest rover ever to land on Mars, five times the size of Spirit or Opportunity, the two previous Mars rovers—  “the most complicated thing we’ve ever sent to another planet,” according to Watkins. If it landed safely and was able to make radio contact with satellites, Curiosity would offer scientists an unprecedented ability to sample and analyze the geological makeup of the planet’s surface, including potential chemical signs of past water habitats. If the landing failed, it could set the Mars program back by a decade or more.

For reassurance, Watkins thought back to all the testing that he and his team had done in preparation for this moment. “We must have run entry, descent and landing thousands of times,” he says. “One thing that’s funny about the space program in general is that we set these incredibly ambitious and aggressive goals—land a car on Mars, send a man to the moon, or whatever it is—but after we say, ‘OK, let’s do something insane,’ we go about it in the most conservative way.”

Above Mars, the spacecraft recognized that it was now traveling slowly enough to cut its parachute. Rocket engines initiated, decelerating the descent vehicle until it hovered above the surface at a near-zero velocity. There, the sky crane maneuver initiated, lowering Curiosity to the ground—safely.

In California, Watkins and Rivellini were finally allowed to celebrate, high-fiving and hugging their team members one after another. “It’s kind of hard to explain to people what it feels like after your $2 billion spacecraft lands on another planet,” Rivellini says. “Truly, the birth of my kids was the closest feeling of elation, joy, and euphoria rolled together. Being part of the leadership team and being able to invent these things and see them happen … it’s what we go to school for.”

For Watkins and Rivellini, as for many of those involved with the landing, that school was The University of Texas. JPL reports that out of some 3,500 total engineers, between 100 and 150 JPL scientists have a UT degree, most from the Cockrell School of Engineering’s Department of Aerospace Engineering and Engineering Mechanics. That’s the highest representation at JPL from any non-California school after MIT.

The UT contingent is so large, in fact, that Longhorn alumni at JPL have come to be known informally as the “Texas mafia.” “A lot of us knew each other in grad school,” Watkins says. “We have a lot of common language when we talk about technical stuff. The way we learned it in class is how we discuss it. There’s also a lot of bonding over football. A lot of UT stickers on people’s laptops. A lot of  ’horns on people’s cars.”

UT’s prominence in the field owes largely to the vision of Byron Tapley, BS ’56, MS ’58, PhD ’60, Life Member, a pillar of the Forty Acres community since beginning his first degree in 1952. If the JPL “Texas mafia” has a godfather, Tapley is it, though with a friendly Texas drawl in place of a Brandoesque mumble. In 1960, Tapley, by then an assistant professor, was offered the chance to teach UT’s first-ever course in aerospace engineering. He countered by suggesting that he create an entirely new department. The rest is history.

At the time, Tapley says, out of all the major U.S. universities, only Yale had such a department. He poached one of their leading professors and set about building institutional ties with JPL, where he spent his summers in the early 1960s.

“The objective was to get people prepared, from an academic point of view, to participate in space exploration,” Tapley says. “The big thrust then was going to the moon.” Times have changed since the moonwalk days, but Tapley’s diligence has been a constant. He helped develop summer internship opportunities for graduate students at JPL that continue to this day and have led directly to the preponderance of UT alumni working there.

He’s also been happy to see the UT-JPL pipeline work in reverse. In recent years, Watkins and JPL have partnered with Tapley and UT on a project called GRACE, which measures mass distribution on Earth from satellites. Just this fall, the department that Tapley created announced the hiring of a new professor, Behcet Ackimese, from the Guidance and Control Analysis Group at JPL.

And this October, JPL and UT signed an agreement making UT an official partner of JPL. “We will leverage expertise, resources, and programs—including the University’s strong aerospace engineering and space science programs—that are relevant to the work being done at NASA and JPL,” said Neil Murphy, manager of Strategic University Research Partnerships at JPL, at the signing. “We look forward to collaborating more closely with the University.”

Watkins was also on hand for the signing. He praises UT’s faculty and curriculum for making the University a world leader in astrodynamics, but as a manager, he most appreciates UT for the breadth of its educational experience. “Breadth is important,” he says. “Other lectures you might see, cultural opportunities—you get a lot of exposure at UT that you might not get at a smaller, more technical school. It requires you to be a socially sophisticated person. You learn to be a better social person, better leader, better manager, and to interact better with your team.”

Watkins hopes that the strategic partnership will lead to more JPL recruitment, not just from aerospace engineering, but also from other departments, like computer science. Tara Estlin, PhD ’98, is an example of the sort of talent he’s hoping to attract. In addition to driving the rovers Spirit and Opportunity, active on Mars since 2004, Estlin won NASA’s 2011 Software of the Year Award for a computer program designed to make planetary rovers more autonomous. This is necessary because, due to planetary rotation, rovers can only communicate with Earth for a small window of time each day. Estlin’s software helps the rovers think for themselves and make better use of their time out of communication with Earth.

Estlin says that UT is particularly good at preparing scientists for the interdisciplinary work that takes place at JPL. “One of the things I love about JPL is you have a lot of people who are very good in all different areas and that have to come together for a project to really work,” she says. “Texas trains you well for that.”

That ability to think unconventionally has come in handy for Estlin and her collaborators many times when operating the rovers, perhaps never so much as when, in 2006, Spirit’s wheel stopped working. “Whenever something goes wrong, like when we lost the wheel drive motor, we get all the experts in the room and we figure out some ways to get around it,” she says.

In that case, the improvised fixes were successful, and Spirit continued roving the surface of Mars for another three years. In fact, the broken wheel turned into a blessing in disguise. As Spirit dragged the wheel along, it churned up a white-coated soil that contained sulfur, perhaps indicating the location of ancient hot springs.  “It ended up being one of our best discoveries,” Estlin says.

In addition to Spirit, Opportunity, and now Curiosity, the Mars program boasts another important piece of hardware: a satellite known as the Mars Reconnaissance Orbiter. Dan Johnston, BS ’84, MS ’89, is mission manager for MRO. His satellite’s high-resolution camera has been indispensable in choosing a landing site for Curiosity and guiding its navigation on the ground. It has also been a vital communication link, receiving signals from Curiosity and relaying them back to Earth.

For Watkins’ team, if not for the general public, the moment when Curiosity first attempted radio contact with MRO was almost as suspenseful as the landing itself. “They’re two different types of radios that have never talked to each other, and the first second they get in view of each other they have to link up to cover the landing and the first few days on Mars,” Watkins says. “Ninety percent of our data comes back via that link. We were constantly tweaking it to make sure it would hook up in the first seconds, and it did. It exceeded all expectations.”

In many respects, the mission would not have been possible without the existing infrastructure represented by MRO. It is, perhaps, a metaphor for the UT presence at JPL—the stronger the existing connections, the more opportunities for the future. “It greatly increases the capability of what we can get through for any one project, having the projects work as a team,” Watkins says. “It’s exciting. We have the beginnings of a real permanent infrastructure on Mars.”

Curiosity is far from finished with its work—the MSL team expects it to explore Mars for another two years at the least, surveying some of the planet’s older topographies for signs of previously habitable water environments. For the next two years, if you read about new discoveries on Mars, it’ll be the fruit of this incredible effort.

That said, the successes of the MSL landing and communications link have already broadened the range of possibilities for future Mars missions. Watkins and his team are hesitant to get ahead of themselves, but they’re excited about what’s coming next.

Rivellini has already moved on to his next project, a test launch intended to prepare for future Mars landings. He and his team will use a balloon the size of three football fields to float a rocket-mounted test vehicle up to 120,000 feet above Earth, where air density begins to mimic that of Mars. From there, they’ll launch the rocket an additional 60,000 feet, where it will reach Mach 4 and burn out. An inflatable and parachute will deploy, and his team will study the dynamics of the test vehicle’s descent.

“I love building extreme machines,” he says with a grin.

One of the next Martian rovers that Rivellini lands may be what Watkins calls a “sample return” mission—a rover that lands with a rocket, goes out to collect rock samples, and places the samples in the rocket to send them back to Earth.

“We’ve had that idea for 20 years, and it keeps getting pushed back,” Watkins says. “But there’s the idea that since we took such big steps with MSL, that maybe we’re ready to take some more big steps with that mission in 2018.”

If a sample-return mission does happen soon, it’ll require more and better autonomy software to be sure that no time is wasted in collecting samples. Estlin will certainly play an important role in that. “If something goes wrong with the rover, you want to be able to cache all your samples before that,” she says. “So there’s a little more time pressure to evaluate things quickly. That’s somewhere that the software that I make can come in and be really important.”

No matter what comes next, Johnston’s satellite should be operative for at least another decade, guiding future missions around the planet and relaying their data back. He’s thrilled at the prospect. “No one else in the world is doing this kind of stuff,” he says. Johnston, a reserved type, grew up on Star Trek and sees his job as an opportunity to live out a childhood fantasy. “To quote a phrase, it goes back to that, ‘To boldly go where no man has gone before.’”

Even Watkins, the successful mission manager, is sometimes startled by the achievements of his UT-heavy team. “We all talk about watching Neil Armstrong on TV when we were kids and how much that meant to us,” Watkins says. “Then when people turn around and say the same thing to us, we think, ‘Us, really?’ It’s like making it to the major leagues or something. It really touches people.”

Photos from top: A rocket carrying NASA’s Mars rover, Curiosity, launches from Cape Canaveral in November 2011 (United Launch Alliance); Mike Watkins; a model of the Curiosity rover; Tara Estlin; Tom Rivellini; and Dan Johnston.

Photos by Matt Harbicht.


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