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Nebraska Engineers helped build the robotic rockhounds allowing scientists to explore possibilities for life on Mars.
Gale Paulsen, MECH '02, a native of Chappell, Neb., is a project engineer with Honeybee Robotics in New York City. He completed his master's degree in mechanical engineering at UNL in 2005 and started working at Honeybee that June, with a focus on drilling and acquiring samples during Mars missions. Honeybee's Spacecraft Mechanisms division was working on the Icy Soil Acquisition Device (ISAD) for the lander of the 2008 Phoenix mission. Near the end of 2006, the project partners (including NASA, Lockheed Martin, and the Jet Propulsion Laboratories) realized the gathering devices "weren't able to penetrate the hard icy soil layer with the scoop alone," Paulsen said. After traversing millions of miles, the Phoenix lander's work would rely on a matter of millimeters.
"While Phoenix was in development, we added the rasp to the robotic arm design specifically to grind into very hard surface ice,"said Barry Goldstein, Phoenix project manager at NASA's Jet Propulsion Laboratory in Pasadena, Calif. "This is the exactly the situation we find we are facing on Mars ... Honeybee Robotics in New York City did a heroic job of designing and delivering the rasp on a very short schedule."
"My focus was on developing the electrical ground support equipment for the rasp in the scoop," Paulsen said. His 14 months of work for this project involved collaborating on initial concepts and design, bread boarding (making small models) and testing the rasp. He also helped with life-testing of the engineering model and with the final assembly of the flight unit. Building the motorized rasp for the robotic arm included designing controls for a mockup of the robotic arm. This unit was tested in a 3' x 3' chamber equipped to simulate the freezing temperatures and low pressure of the Mars environment. Paulsen was relieved that the ISAD worked well.
The experience tapped his Nebraska Engineering education, where Paulsen said he picked up "a lot of good skills in control design to apply directly to the system." His major influences included studying with Shane Farritor's robotics lab at UNL and working two summers at the Jet Propulsion Laboratories in Pasadena, Calif., with funding through Nebraska's Experimental Projects to Stimulate Competitive Research (EPSCoR).
For Paulsen, the summer 2007 launch of the Phoenix mission meant nearly a year of waiting to see how the landing, and then use of the robotic arm and rasp, would fare on Mars. The May 25, 2008 landing was successful, and NASA reported in July 2008 that the lander on Mars used its robotic arm "To clear away loose soil from a subsurface layer of hard-frozen material" in a trench informally named "Snow White." The powered rasp generated ice shavings collected by the scoop on the back of the robotic arm, to deliver a sample of icy soil into one of the lander's laboratory ovens for testing.
On a future mission, the gathered grit could enter sample manipulation systems (SMS) worked on by Honeybee colleague, and fellow Nebraska Engineering alumnus, Erik Mumm.
Mumm earned his master's degree in mechanical engineering at UNL in 2002, and is a system engineer with Honeybee. He is working on the SMS for the fall 2009 launch of the Mars Science Lab Rover. In this work, Honeybee is a subcontractor to Goddard Space Flight Center, which is building Sample Analysis at Mars (SAM): a suite of instruments, including three spectrometers that scan samples to analyze whether life could exist, or has existed, on Mars.
"After Phoenix, we are next in the queue for Mars," Mumm said. "Currently we have delivered the flight unit, integrated for SAM testing. Next up this fall is a simulation test in a thermal and vacuum chamber that simulates temperature and pressure for the vacuum of space and on the surface of Mars."
"We will also place the instrument on a shaker table and simulate the launch environment to ensure the design and workmanship will endure the ride to Mars," Mumm said. "These units really get beat up while we're checking for unforeseen problems."
The Rover is designed to collect solid samples at the Mars surface and convey them to the SMS' 74 sample cups stored on a carousel. The samples then move to the pyrolysis oven with its airtight seal. The oven heats to 1100 degrees Celsius, Mumm said, which vaporizes the samples into gas that is plumbed to spectrometers and analyzed. A bake-out to 92 degrees Celsius for eight days allows non-metallic components to outgas in the vacuum.
"We want to be confident when we move the sample from inlet to pyrolysis that nothing else affects our sample measurements," Mumm said. "Preventing contamination is a big factor in our design, because you don't want to bring anything like that with you to Mars. "The sample manipulation system must be extremely clean and sensitive, to measure on a scale of parts per billion."
It's challenging work, but Mumm enjoys it: "Terrifyingly exciting—it gets in your blood." He always liked space exploration, but a turning point was seeing the Pathfinder Rover land on Mars: "I saw this shoebox size thing moving around on Mars, and I was hooked," Mumm said. Joining Farritor's mechatronics program at UNL opened more doors.
"Working with Shane led to my internship at JPL, where I got into Mars robotics," Mumm said. He learned of Honeybee and liked the idea of living in New York City (a big change from growing up in Kearney).
"Honeybee has 35 to 40 employees, mostly engineers, and it's a dynamic place to work ... you get freedom and valuable experience," Mumm said. "I love the work—it ranges from environmental testing of flight hardware to proof-of-concept testing on low fidelity prototypes. There's a ton of analysis and building small prototypes, all with the overall focus on mitigating risks as early as possible in the program."
Farritor recalled Paulsen and Mumm in his program: "They were good students, hardworking and about as smart as you can get." It's no surprise to Farritor that these alumni are doing great things, but he said he misses playing basketball with them on campus.
Honeybee Robotics President Chris Chapman values the Nebraska connection in his company's operations. So far, it has meant "two highly dedicated and talented engineers who have proven to be solid self starters," said Chapman.
"In addition to being highly intelligent and creative in their approaches to engineering tasks, Erik and Gale have demonstrated some of the strongest work ethics that we've seen at Honeybee over the years and have led the charge on the various projects they've been involved with to date."
Chapman added, "If you have any more like them, please send them our way!"
For Nebraska Engineering students interested in advancing space exploration and their careers, this invitation might be just the ticket.
- Carole Wilbeck