Chris Voorhees, President of First Mode, and engineers Brian Geddes and Sophia Kim check the newly completed goniometer before shipping it to Western Washington University. (GeekWire Photo / Alan Boyle)
The 3 foot wide device, built in First Mode’s Seattle workshop, looks like a science fiction movie with spinning gears and a flashing beam of light – and it really does have an extraordinary purpose: to help scientists interpret Readings from Mars.
Even the word that describes the gizmo has a science fiction sound to it: “goniometer”.
Today, First Mode’s engineering team delivered the 3-D goniometer to Western Washington University’s Mars Lab in Bellingham, Washington, where it will be used in conjunction with NASA’s Perseverance rover mission.
First Mode worked with Western to design the goniometer under a contract for $ 302,000 from NASA, and it has already been given a fitting NASA-like name. It is known as Western TANAGER, which is an acronym that stands for “Automated Goniometer Using Three Axes, N-Samples for Evaluating Reflectivity”.
The name pays homage to the Western Tanager, a bird that can be spotted in Washington and other western states. “I’ve said that bird feathers are color-coded by both pigment and viewing angle,” Kathleen Hoza, systems engineer at First Mode, told GeekWire.
Western’s new goniometer may look like something Buck Rogers would use in the 25th century, but such devices actually date from the 16th century. Goniometers are designed for precise angle measurements, similar to the protractors used in elementary school.
The Western TANAGER gets to the heart of things by measuring angles in three dimensions. Why is this important for Mars? Because knowing the exact angles of reflection for sunlight hitting Martian rocks could help scientists unlock some of the red planet’s geological secrets.
Practically every Mars mission has at least one spectrometer with which the composition of rocks can be determined based on their absorption levels for different wavelengths of light. When light levels drop at certain wavelengths, geologists can determine the proportions of the elements that are present in a given rock.
“The component that adds to this is that you can look at that dip … and you can say, ‘Well, is this absorption feature the same for all geometries? ‘When you move the light source, does this absorption function change or does it stay exactly the same? “Explained Hoza.
Seeing how absorption levels change at different angles of reflection – for example, as the sun moves through the Martian sky or when the Perseverance Rover moves around the rock – could prompt geologists to optimize their analysis of the rock’s composition.
“Maybe you can even use that to learn new things,” said Hoza.
If the reflectivity of the rock changes in certain ways from different angles, it could tell scientists that the rock is covered with a fine layer of silica. And this silica could serve as an indication that liquid water once covered the region around the rock – which would be an important finding pointing to possible habitability in ancient times.
This is where the western TANAGER comes into play: Researchers on Earth can use the goniometer to simulate the conditions under which the observations were made on Mars. Sophia Kim, a human resources engineer at First Mode who focused on building the goniometer’s mechanical systems, said the gizmo serves as a “look-up table” to match Mars data with terrestrial geological features.
Some of the rocks used as reference samples were collected from regions in eastern Washington state that have long served as replacements for Martian terrain.
Geek of the week: Kathleen Hoza’s curiosity drives scientific work in First Mode
Hoza began working with goniometers while studying at Westerns. She built a 2-D goniometer for her master’s thesis and played a leading role in building the more complex 3-D version in First Mode.
The Western TANAGER will spend the night in the laboratory of the WWU planetary scientist Melissa Rice, who is part of the science team for the Mastcam-Z camera system from Perseverance. Like Mastcam-Z, the terrestrial goniometer can perform spectral measurements in visible wavelengths and in the near infrared – which makes for a perfect pairing.
Hoza said that the instrument built by First Mode to interpret Mastcam-Z results could come into play, but that doesn’t stop there.
“That’s one of the nice things about how wide the applications are,” she said. “We could actually go back and visit spectral data from all the different missions and look at measurements that were made in correlation with the viewing geometries and see if that had any effect.”
After the Western TANAGER has landed in Bellingham, Hoza is concentrating on her next project in First Mode: helping with the hardware for NASA’s psyche mission to a metal-rich asteroid.
“To be a person who understands both the scientific questions and the technical reasoning is a big goal that I have,” she said.
Hoza wants to close the gap that often develops between science and technology.
“I think wires can be crossed and messages can be overlooked,” she explained. “There can be engineers who focus on problems that aren’t really important, and scientists can’t get their questions right so that an engineer knows which system is right. I am very excited about the opportunities that allow me to work at the intersection of these two things. “