The STELLA (Science and Technology Education for Land/Life Assessment) project uses spectrometers that can be built with low-cost components and 3D printed housings to introduce NASA Earth observation technologies and provide authentic hands-on learning experiences for remote sensing education. STELLA instruments help engage students in the quantitative aspects of satellite data, provide insight into the scientific process, and encourage analytical thinking.

STELLA 2023 summer intern uses a multimeter while building a STELLA instrument.
Building STELLA instruments provides the opportunity to learn engineering design concepts and gain an appreciation for the instrument development process. Above: NASA high school intern, Sabrina Pillai, shows a younger student how to troubleshoot a STELLA-1.1 device using a digital multimeter.
Student in a classroom wearing a red sweatshirt, holding a STELLA spectrometer over a green plant leaf. There is a projector behind him displaying the STELLA data viewer.
The STELLA Data Viewer can be used to display spectral data for analysis. Above: A middle school student measures a healthy plant using a STELLA-1.1 spectrometer, with the spectral measurements displayed on the Data Viewer.

STELLA Spectrometers

STELLA spectrometers measure energy throughout the visible and infrared portions of the electromagnetic spectrum. These DIY devices can be built with inexpensive and widely-available components.

There are four versions of the STELLA spectrometer to accommodate a variety of interests and needs. Assembly of the STELLA-1.0 and 2.0 versions requires soldering and 3D printing. The STELLA-Q and Q2 versions do not require soldering or 3D printing and are ideal for students of all ages. All units use CircuitPython, a beginner-friendly version of the open-source Python programming language.

Data Viewer

Data collected by the STELLA spectrometers can be displayed and analyzed using the Data Viewer. This spectral data reveals information about the physical environment beyond what the human eye can see such as vegetation health, moisture content, and mineral composition.

STELLA-Dataviewer reflectance graph of healthy vegetation
A graph from the STELLA Data Viewer shows the reflectance of a healthy leaf across portions of the electromagnetic spectrum, as observed by a STELLA 1.1 spectrometer. This graph shows higher reflectance in the green wavelengths, indicating that this plant is green. Chlorophyll absorbs all colors of visible light except green. The highest absorption occurs in violet-blue and red regions of visible light. Healthy vegetation absorbs red light for photosynthesis and reflects a significant amount of near-infrared (NIR) light.

STELLA for Outreach

STELLA spectrometers help engage the public by demonstrating how multispectral data are collected by remote sensing instruments like those on the Landsat satellite. The current versions of STELLA spectrometers sense visible and near-infrared wavelengths—portions of the electromagnetic spectrum also observed by Landsat. However, the modular nature of STELLA’s open-source design enables modification to fit outreach demonstrations for other Earth-observing missions.

Michael Taylor (left) discusses Landsat and spectral signatures with NASA Headquarters employees including Bill Nelson, the NASA Administrator (second from left).
Michael Taylor (left) discusses Landsat with NASA Headquarters employees including Bill Nelson, NASA Administrator (second from left).

STELLA for Education

STELLA introduces students to remote sensing concepts through hands-on instrument development and data collection. By building their own spectrometers, students are exposed to mechanical and electrical engineering concepts such as sensor assembly and light detection. By using their devices to collect data samples, students can learn how spectrometers work and discover proper data collection practices. Students can also learn about instrument calibration by ensuring consistent and precise measurements from STELLA units. Additionally, they can learn the basic programming skills needed to ingest and analyze the data.

STELLA in classroom
Paige Williams uses a STELLA spectrometer with the STELLA Data Viewer in her classroom to teach remote sensing concepts.

Note: STELLA is solely an educational and outreach tool designed to help students and the community learn about Landsat and remote sensing. The performance of STELLA has not been scientifically peer-reviewed and data retrieved should be used for educational purposes only. Find more information on the capabilities and limitations of STELLA data in Technical Details. 



STELLA Spring Webinar: April 15, 2024

STELLA users will talk about their experiences using the DIY spectrometer during this webinar. Panelists include Bianca Cilento (RIT), Karen Karker (SUNY), and Peder Nelson (OSU and NASA GLOBE Observer).

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