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Kobie Boykins ’96 (left) served as cognizant engineer for the rovers’ solar array structures and mechanisms. Boykins also worked on the assembly, test, and launch operations team, responsible for building and testing the flight hardware and delivering it to Cape Canaveral for launch.

Testing, Testing
Jim O’Donnell ’85, Ph.D. ’92, contributed to the mission as part of NASA’s Professional Development Program. From March through May 2003, O’Donnell helped perform last-minute reviews of the design, integration, and testing of the rovers to make sure they were ready for launch.

“With NASA, you get to work on spacecraft designed to make life better on Earth and to explore the universe,” says O’Donnell, who’s based at Goddard Space Flight Center in Washington, D.C. “It’s hard to describe the feeling of watching something you’ve worked on for months and years launch into space and go on to carry out its mission.”

At JPL, Jim Donaldson ’78, M.S.’79, was the lead engineer for the Avionics Subsystems. His team designed and built the electronic boxes that contained the rover’s computer, as well as interfaces for communicating with other systems. His work was crucial to the rover’s performance during the cruise and landing portions of the mission.

In addition, Donaldson’s team collaborated with engineers from Swales Aerospace, an engineering services company founded by Thomas Swales, M.S. ’62, in 1978. The Swales Electronic Packaging Group sent three engineers to work in the avionics team lab for a year and a half, where they built test and ground support equipment and wrote test software.

Fabien Nicaise ’00, MBA ’01, conducted early tests of the mobility system and the high-gain antenna, and designed some of the equipment that built the rover’s mobility system. Shawn Goodman ’89, M.S. ’91, another employee at JPL, also added his talents to the Mars rover project.

Dave Johnson ’01 was involved with testing the pyrotechnics, controlled explosions that release obsolete hardware during the mission. He says it was the testing team’s job to make sure the rovers were super-reliable.

“Our concern was that these explosions could damage sensitive equipment. And when you’re sending something to Mars, once it’s gone, you can’t tweak it,” says Johnson.


Mars 101

Mars rotates approximately 40 minutes slower than Earth every day. Since each rover operates when the sun is pumping energy onto its solar panels, the slower rotation of Mars boils down to a longer day in which the mission team can use a science instrument, drive a little farther, or send more data to Earth.

Fourth planet from the Sun, the next beyond Earth

Revolves around the Sun once every 687 Earth days

Length of a Martian Day or “sol”— 24 hours, 39 min., 35 sec.

Atmosphere is mostly carbon dioxide (95.3 percent), nitrogen (2.7 percent), and argon (1.6 percent)

Surface Winds up to 40 meters per second (80 miles per hour)

Surface Temperature averages -53 C (-64 F); temperature varies from -128 C (-199 F) during polar night to 27 C (80 F) at equator during midday

Gravity only 38 percent as strong as Earth’s

Two irregular Moons, each only a few kilometers wide: Phobos (larger moon) and Deimos (smaller)

Average Diameter 6,780 kilometers (4,212 miles); about half the size of Earth, but twice the size of Earth’s moon

Average Distance from the Sun 227.7 million kilometers (141.5 million miles)

Distance from Earth varies from 54,500,000 kilometers (33,900,000 miles) to 401,300,000 kilometers (249,000,000 miles)

Co-op Success
Johnson, like most of the Rensselaer graduates working on the rovers, got his start at JPL as a student co-op. He worked on a proposal for a helium balloon that would measure cosmic radiation. Amy Meyer built composite parts for a variety of missions. And Voorhees and Boykins got their start on the Pathfinder mission.

“They put us in a room and gave us a little stamping machine and a pile of stainless steel cutouts and we stamped out thousands of cleats for the Pathfinder’s wheels,” recalls Voorhees with a chuckle. “You’re kind of slave labor, but the cool thing is, you get exposed to all the facets of what they do here.”

In contrast, Mike Gradziel ’03 had the good fortune to co-op at JPL during crunch time for the MER mission.

“Last summer, all the work was coming together, we were behind schedule and over cost and the engineers began delegating portions of their jobs to whomever they could find,” says Gradziel, who was asked to coordinate a last-minute test of the rover’s braking rockets. “Co-ops were really given a chance to run. We were treated like full-time employees.”

Gradziel also designed and built equipment to test a system that tracked the lander’s sideways velocity. If the lander traveled too fast to one side, rockets could be fired to compensate. Gradziel says it was a small contribution, but one that proved crucial during the Spirit’s landing.

“If we hadn’t designed and tested the system properly, it’s very likely the Spirit landing could have failed because it was moving so fast sideways, the airbags might not have withstood the impact,” says Gradziel. “When the rockets were fired during the descent, we realized it was a good thing we tested it and made sure it worked.”

Today, Gradziel is a full-time employee, working on the next Mars mission, scheduled for 2009.

“It continues to surprise me how quickly I’ll be put in a position where I am responsible for delivery of a set of hardware that’s critical to high-profile missions,” says Gradziel. “It’s a wonderful place to acquire knowledge and experience.”

Like Gradziel, many of the Rensselaer engineers responsible for the Mars rover project are in their 20s and early 30s. That doesn’t surprise Diana Leis Delker, Rensselaer’s director of cooperative education.

“There’s a definite passion, a certain spark to the students who want to go to NASA that sets them apart from the typical co-op applicant,” says Leis Delker. “These are the kids who are hanging around your door asking if you’ve heard anything yet.”

The students typically spend seven to eight months working at JPL during the school year, then return for a summer assignment. Rensselaer has sent 63 students to JPL over the past decade, and several more have accepted co-op positions at other NASA sites. Leis Delker says NASA recruiters have typically favored Rensselaer students.

“We hear back that they’re very bright, very intelligent students. They have excellent communication skills and a strong focus on what they want to do,” she says.

All of those skills were put to the test as the rover teams approached Jan. 3, 2004 — the date the Spirit rover was scheduled to enter the martian atmosphere.

As the navigation team chief, Louis D’Amario ’68 (photo) had spent months, and many hours of calculations, mapping a trajectory that would hit the bull’s eye at the top of the planet’s atmosphere. The navigators had six opportunities to employ trajectory corrections — rockets that would adjust the rover’s direction as it cruised through space. But D’Amario says the rovers were so on target, the navigators only used four corrections for the Spirit and three for Opportunity.

“As it turned out, we hit the target very accurately,” says D’Amario. “It’s like we were teeing off in Paris and trying to put the ball into a cup in Tokyo, six thousand miles away.”

When D’Amario needed to adjust the rovers’ direction, he turned to Fred Serricchio ’94, a member of JPL’s Attitude Control System team. It was also Serricchio’s job to keep the rovers’ solar panels pointed toward the sun while their antennae pointed toward Earth, enabling communication.

“We used the sun and stars to make sure we were turned the correct way,” says Serricchio. “It wasn’t easy, because Mars is spinning and the Earth is spinning while both are orbiting the sun.”

Once the rovers landed — Spirit on Jan. 3 and Opportunity on Jan. 24 — Serricchio began a 90-day stretch of nonstop working as the rovers moved around Mars, collecting data. He says living and working on martian time affected his sleep schedule in the same way a newborn baby does. Serricchio’s two sons, now 3 and 5, didn’t fully comprehend what their dad was doing. But as he tucked them into bed before going to work, they’d say, “Go drive your rovers, Daddy.”


Continued
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Rensselaer Magazine: Summer 2004
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Rensselaer (ISSN 0898-1442) is published in March, June, September, and December by the Office of Communications.

 
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