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All in a Sol's Work

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Twin rovers, Spirit and Opportunity, are now exploring Mars in extended missions after successfully completing all tasks set for them in their primary three-month missions at sites halfway around Mars from each other.

A group of Rensselaer’s alumni help to engineer a historic mission to Mars

By Karen Kelly

One of the most memorable pictures of the Mars Exploration Rover mission wasn’t taken on the surface of the red planet. Instead, it was taken on planet Earth, as NASA scientists and engineers jumped with glee and “high-fived” each other when they received the first signals indicating the Spirit rover had landed safely.

Among those celebrating were more than a dozen Rensselaer graduates who were watching as the parts and systems they had designed and built performed flawlessly, enabling the rover to land on the surface of Mars in January.

Doug Johnston ’02 (photo), an engineer in the radio science group, was the first to receive the Spirit rover’s signal. Fred Serricchio ’94 (photo) steered the rover into the martian atmosphere, firing rockets to adjust its direction. And Chris Voorhees ’96 (photo), designer of the rovers’ mobility system, started preparations to drive the rover off the lander and on to the martian surface.

They are part of a long line of Rensselaer alumni and faculty involved in space-related research and exploration. Rensselaer people have played significant roles in the Apollo program, the first Mars rover, numerous experiments on space shuttles, solar system research, and even space travel.

Living on Martian Time
While this mission has been a resounding success, these alumni say that behind the scenes, it was all-consuming. They worked long days, seven days a week. Vacations were scarce, and friends and family obligations were placed on the back burner. Even now, Voorhees, the lead engineer responsible for driving the Spirit rover around Mars, is living and working on martian time — arriving 40 minutes later each day. A martian day, or “sol,” is 24 hours, 39 minutes, and 35 seconds long.

“Shades are pulled on every floor so you really can’t tell what time it is,” says Voorhees, who was preparing to report to work at NASA’s Jet Propulsion Laboratory (JPL) at 4:30 a.m. “I started working on this project in May of 2000, when we were just dreaming it up. And it’s been intense ever since.”

Voorhees is one of the few engineers who’s been with the rover project from “cradle to grave.” He was responsible for the design, assembly, and testing of the rover’s wheels, drive train, and steering system. Once that was completed, he became the lead integration engineer for the Spirit rover, overseeing its assembly, as well as testing and preparation for launch. Finally, Voorhees joined the operations team as the mechanical systems flight controller, the person responsible for the rover’s deployments on the martian surface.

It’s not surprising that Voorhees is frequently cited by the other alumni as someone who personifies the demanding work ethic expected on the Mars Exploration Rover (MER) project. His wife even made up T-shirts that said “MER Widow” for herself and some of the other spouses.

“The schedule was extremely tight — nothing was done before it absolutely needed to be. We were working on problems with the spacecraft right up until the week of the launch,” says Voorhees.

The deadline for the mission was inflexible because scientists wanted to take advantage of the planet’s proximity to Earth. Soon after the Spirit and Opportunity were launched last summer, Mars was the closest it’s been in the past 30,000 to 40,000 years — about 35 million miles away.


This approximate true-color image taken by the panoramic camera on the Opportunity rover shows the impact crater known as "Endurance." Endurance is roughly 130 meters (430 feet) across. This image mosaic was taken by the panoramic camera's 480-, 530- and 750-nanometer filters on sols 97 and 98. It consists of a total of 258 individual images.

“We were dependent on the planetary alignment,” recalls Jason Suchman ’94, who was lead engineer for the Pancam Mast Assembly, the large white mast on top of the rovers that carries the panoramic cameras. “You can’t slow Mars down, so we’d either be there on the launch pad or we wouldn’t.”

However, NASA usually spends at least four to five years developing these missions. So when the team started designing the rovers in 2000, Voorhees says it was already running behind schedule.

“It’s hard to schedule creativity, to come up with something brand new on such a tight timetable,” says Voorhees. “We were constantly trying to push the system forward, trying to get the hardware done, get it tested, delivered, get it integrated together. That process was kind of a drumbeat in the background right up until the landing.”

It also left little time for solving problems, as Andy Stone ’94 (photo) experienced firsthand. A senior member of the rover engineering staff, Stone was the lead engineer responsible for the Rover Primary Structures, including the Warm Electronics Box (WEB), which holds the rover’s electronics, battery, and radiator.

“The original design was like a scaled-up version of the Pathfinder rover structure, but we found out that the idea didn’t scale very well,” says Stone, referring to the 1997 mission. “Then we had to come up with a new design — fast.”

Amy Meyer ’99, who worked for Stone as the lead engineer for the rover’s battery assembly, also had a scare late in the design process.

“We had a pretty mature design for how the batteries would fit into the WEB. Then I received a call from the manufacturer saying we may want to change their positioning. That’s a huge thing. It affects the entire design,” says Meyer, who now works at Lockheed Martin Space Systems in Sunnyvale, Calif. “It turned out fine, but it was a scary time.”

As the designs were completed, the rover teams moved into the testing and integration phase, in which engineers like John Beatty ’97 (photo) began fitting the pieces of the rover together.

“The assembly process for the rover bodies was amazing because there were so many people and so many parts involved,” says Beatty, who designed the large metal structures used to assemble the WEB and the rover’s equipment deck. “It was incredibly messy — pink adhesive was everywhere — and we had to get it right the first time. Once glued, it doesn’t want to come apart.”

Like everyone else, the teams testing and assembling the rovers were rushing to beat the deadline. But Kobie Boykins ’96 (photo), the lead engineer for the Rover Solar Arrays, or solar panels, said the teams had to remain cautious.

“The details are important — how many bolts, what type of bolts, which wrench do we use,” recalls Boykins, who also oversaw the assembly of the Rover Equipment Deck. “It becomes very tedious, but that’s what you do when you’re the foreman in the shop.”

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Rensselaer Magazine: Summer 2004
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