Rice’s spectral eyes bound for the skies

NASA awards grant to Rice to develop snapshot spectrometer for Earth observation 

Rice University bioengineer Tomasz Tkaczyk is widening his view from the health of cells to the health of the planet through a new grant from NASA.

Tkaczyk and Rice Space Institute Director David Alexander will develop technology to place a small, sophisticated spectrometer in the air or in space for remote sensing of surface and atmospheric phenomena.

A portion of a spectral image recorded by a Rice spectrometer being developed for aerial and space applications shows one rainbow-like distribution from each optic fiber output to the camera. As in laboratory spectroscopy, the color bands can be interpreted to indicate the amount and type of chemicals in the field of view. Courtesy of the Tkaczyk Lab

The $2 million, 3-year award to Rice was part of $53 million in grants announced by NASA’s Science Mission Directorate. All 17 grants will fund proposals to the agency’s Instrument Incubator Program to develop innovative instruments and technologies for future Earth science methods and observations.

The Rice device is called the tunable light-guide image processing snapshot spectrometer (aka TuLIPSS). Tkaczyk expects to have a high-fidelity prototype ready for flight testing on a high altitude balloon by the end of the grant. It will allow NASA to capture images and spectra instantly in visible and near-infrared light, aiding in the analysis of a number of atmospheric and surface conditions from algae blooms and other contaminants in coastal waters to lightning strikes in major storms.

Tkaczyk, an associate professor of bioengineering, is an optics expert whose lab specializes in portable instruments for rapid, point-of-care medical diagnostics and treatment. But he was inspired to look skyward by continued conversations with Alexander at their daughters’ soccer matches and, subsequently, through a pilot project with NASA’s Marshall Space Flight Center in Alabama, which will test Tkaczyk’s spectrometers on drones for analysis of conditions on the ground. Other collaborators are Burgess Howell at the Universities Space Research Association in Huntsville, Ala., and scientists at the National Center for Atmospheric Research High Altitude Observatory in Colorado, which hopes to fly the instruments on a high altitude balloon in 2019.

David Alexander

“I’ve been working in the biomedical space for some time, but my training is not medical at all,” Tkaczyk said. “It’s optical metrology, measurements. That’s where I started, but I see a lot of what we’ve developed as platform devices. The applications in the medical field provide a very good outlet, but there are other opportunities for the same devices.

“We’ve been looking at using our systems for spectroscopy in tissue or basic basal cell signaling experiments and in diagnostics, but we can also see there are opportunities for environmental diagnostics, remote sensing or the detection of high-speed phenomena,” he said.

The instrument will be small but powerful, Tkaczyk said. Its adaptable design uses densely packed fiber optic waveguides coupled with electronics that can read spatial or spectral information, or a combination of the two. The spatial information provides the scale to which researchers can resolve the actual structures being studied while spectral information allows the differentiation of target compounds, like chlorophyll or nitrous oxides.

A snapshot spectrometer will be important for space-based applications where a platform like the International Space Station, which travels 7 kilometers per second in low-Earth orbit, doesn’t have the luxury of pausing over a single location. “The ability to collect data across an entire scene in a single exposure makes TuLIPSS uniquely suited to a range of Earth science applications, including the ability to record transient surface and atmospheric phenomena, and to provide multiple views through an atmospheric column for tomographic studies,” Tkaczyk and Alexander wrote in their proposal.

Rice bioengineer Tomasz Tkaczyk and graduate student Ye Wang work at the bench prototype of a spectrometer being developed for aerial applications. The NASA-funded project is intended for use in the air or in space for remote sensing of surface and atmospheric phenomena. Photo by Jeff Fitlow

“The versatility of the proposed instrument allows us to consider a number of different observation platforms like drones, aircraft, balloons and satellites, and a wide range of remote sensing applications,” said Alexander, a professor of physics and astronomy at Rice. He noted the NASA review panel was enthusiastic about applying technology from a different field for Earth science.

Alexander said the technology is open-ended enough that neither he nor Tkaczyk can yet imagine all the possible benefits. “By spanning optical to near-infrared wavelengths, the instrument will provide critical information on land use, water use, atmospheric pollutants and other diagnostics for scientific, ecological and humanitarian applications,” he said.

The platform’s future has few limits, said Tkaczyk, who sees his tiny, versatile spectrometers being deployed on cube satellites arrayed around the planet or even on rovers or probes sent to other planets.

“There’s a lot of opportunities, and I’m very open,” he said. “And space seems like an exciting opportunity. I’ve always appreciated the connection Rice has to the space program, and I’ve always wanted, a little bit, to be a part of that.”