Published May 31, 2004; Category: ARTS & SCIENCES
When asked about her job, Kristina Lynch usually says she studies the Northern Lights - the dancing auroral lights that often appear in the night sky.
"It sounds better than saying I'm a rocket scientist," she says. Both are true, of course. Lynch studies the aurora, and to do that, she builds rockets.
Lynch, Assistant Professor of Physics and Astronomy, is trying to figure out what causes the structure in the aurora.
"We understand the basic picture of how the Northern and Southern Lights work; it's the activity of charged particles, electrons, hitting the air in the atmosphere. But we don't understand exactly what makes all the pretty, dynamic fine structure."
Examining the aurora requires specialized rockets equipped with sensors to measure electrons and ions, and capture information about the electrical and magnetic fields. The data is relayed back to earth in real time during the rocket's flight of 300 to 600 miles into the air. As the rocket flies through and over the aurora, spring-loaded, sensor-laden payloads come apart during the trip at a predetermined time. The goal during the 10- to 15-minute ride is to take an array of measurements through time and space in order to get a more complete understanding of how the aurora is constructed.
"Some auroras look like they have this rippling curtain effect," says Lynch, "and other times they swirl around. If a rocket only takes measurements as it moves through the aurora at one point in time, the sensors can't differentiate between the two phenomena. It looks the same both ways to the sensors."
To meet this challenge, Lynch and her students along with collaborators at Cornell University have increased the number of payloads on their rockets. Grouped payloads can measure more variations and gradients in the aurora. Last December, the group gathered in dark, cold, but beautiful (according to Lynch) Svalbard, Norway, to launch a rocket with two payloads. Winter months at high latitudes yield more active, brilliant auroras. This summer they will build a five-payload rocket to launch in Alaska in February.
With each payload that is added, the team must compact the electronics inside it to keep the rocket from getting too big and heavy to travel the necessary distance above the atmosphere. Inside each payload, there are many circuit boards to control the experiments. Each board requires hundreds of electronic parts that are interconnected and attached to it. Students Sarah Jones '04 and Jonathan Tullis '05 with graduate student Rob Michell will spend a great deal of this summer soldering and testing the circuits. Lynch says that many of her past students have applied their rocket building experience to embark on careers in satellite technology.
"There is so much to learn about the aurora; more questions come up all the time."
- Kristina Lynch
Another student, Sarah Markus '07, who participates in Dartmouth's Women in Science Project, works on outreach initiatives to help a broader audience understand the science behind the rockets. Markus is creating a web page, and she will also work this summer with graduate student Kristen Frederick-Frost developing an exhibition in collaboration with the Montshire Museum of Science in Norwich, Vt. The exhibition will describe the different elements of an auroral rocket and explain the difficulties and complexities of taking measurements in space. (See www.dartmouth.edu/~aurora.)
Lynch dreams one day of building a rocket with a 50-payload cargo, which she says should be only about 10 to 15 years away.
"There is so much to learn about the aurora; more questions come up all the time," she said. "The more payloads we deploy, the more information we gather about how the energy is transferred and how the rocket itself might influence the energy readings we get, the more interesting questions we find."
The research is funded by NASA.
By SUSAN KNAPP
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Last Updated: 12/17/08