Helping scientists "see"

Tuesday, November 23, 2010
by Matthew C. Button

Alberto Behar
Alberto Behar stands on the skid of a helicopter to deploy a GPS unit to measure glacier movement.

It is an easy thing to want to take a picture or a temperature. But it’s not so easy to make these observations in the distant emptiness of space, the dark depths of the ocean, or the cold, slippery ridge of a glacier. Extreme surroundings can annoy scientists because their ability to observe an environment is hindered by the environment itself. To solve this problem, top researchers look to scientist-engineers to overcome the challenges of using sensors in extreme conditions.

Alberto Behar is an infrastructural specialist in ASU’s School of Earth and Space Exploration. He comes up with new ways to attach sensors to robots, vehicles and other observational mechanisms. In short, he gets sensors where they can do their job.

For example, John Adler, an expert in unmanned aerial vehicles (UAV), was interested in West Greenland’s melt ponds. Melt ponds occur on top of glaciers when summer sunlight warms portions of the ice, creating lakes of fresh water. Often, tubes develop beneath still-frozen glaciers to form an interconnected web of melt ponds. Information about these melt pond depths can offer clues about the movement and disintegration of glaciers.

Adler needed a way to measure the depth of the ponds. He conceived of using a hyper-spectral camera to measure depths from a flying aircraft. But he needed a way to attach the sensor to the aircraft.

Adler came to Behar for help. Behar designed a mount out of a high-tech 80/20 materials, what he called a “fancy erector set.” This allowed the camera-like sensor to slide out of a helicopter’s door mid-flight.

A simple fix? It may sound like it, but these mounts and attachments can actually be quite complicated. Behar has to take into account the distance from the helicopter required to take proper depth measurements, Greenland’s aircraft regulations, and the stability needed for accurate measurement. He also had to come up with a “mow-the-lawn” pattern to cover and map out the depth of the whole pond.

Researchers on a glacier

Another recent project involved the design of a robot that could descend through a 500-meter tube of drilled Antarctic ice and 500 meters of ocean water to take pictures of ice layers and ocean-ice interactions. As this probe neared the bottom of the ice shelf it captured rare and unexpected images of a shrimp-like creature, proof of a life form that was not expected in this environment.

Behar designs tools for even more extreme environments than glaciers and oceans. For example, he is involved in the construction of the next Mars rover. The rover is nearly completed and is in its testing phase. Behar is working on the Russian-built Dynamic Albedo of Neutrons sensor. The sensor shoots out atomic particles called neutrons. When the neutrons bounce back, scientists analyze them with a spectrometer to find out the percentage of water up to one meter below the surface of Mars.

The instrument is mounted in the rear of the robot, aimed toward the ground. It must be specially aimed and secured to ensure accurate readings. The rover will be tested in extreme environments that mirror Mars’ landscapes, like the desert or tundra.

“Oftentimes we use extreme areas to test apparatus’ that we might someday use in space or on other planets,” Behar explains.

For example, Behar worked on creating a “Cryorobot” that used a miniature hot water drill to bore through ice. The robot itself was being designed to investigate Mars’ polar ice caps. However, first it needed to be extensively tested on the Greenland ice cap.

Each one of these designs is the outcome of careful communication between Behar and the scientists wanting to take the measurements.

“Together we find the solution to these problems with a back and forth discussion and evaluation until we find a way we think will work, and then we’ll build it,” says Behar. From simple fixes to improve efficiency, to delicate projects involving sensors on far-away worlds, Behar is up to the task. We know a wedge can split wood, but it needs a proper handle before you can call it an axe. Behar designs these “handles,” helping tools do their jobs right. Science is all about observation. Behar helps scientists observe things that aren’t readily apparent to the naked eye. This helps us all understand our world—and solar system—a little bit better.