Galassia: students build a changing mission

The National University of Singapore, or NUS, launched Galassia in December 2015 with Kent Ridge 1. Students and researchers developed the small spacecraft to carry experiments in quantum technology and ionospheric electron content. The quantum payload was an early step in a later research sequence; carrying such an experiment did not establish an operating satellite-to-ground quantum communications network.

Galassia-2 followed in July 2023 with a different task: multispectral — open definition observation for agriculture and environmental change. The family connects engineering education across successive projects, rather than requiring every satellite to repeat the first payload. Its student teams worked across mechanical design, electronics, software and control. Successful launch began a period of stabilization, contact checks and subsystem verification before routine observations could be assessed.

The Galassia-2 design includes green, red, red-edge and near-infrared measurements. Red and near-infrared reflectance — open definition can support a normalized vegetation index, commonly called NDVI — open definition. In simplified form, subtract red from near-infrared reflectance and divide by their sum. The result emphasizes a relative spectral contrast instead of merely reporting the overall brightness of the scene.

Suppose fictional calibrated reflectances are 0.6 in near infrared and 0.2 in red. The difference is 0.4 and the sum is 0.8, giving an index of 0.5. This number is not a Galassia observation or a direct measurement of crop yield. Soil background, atmosphere, clouds, season and plant type can affect interpretation. A useful agricultural conclusion needs appropriate comparison observations and ground knowledge.

A normalized spectral comparison

The mission-planning system must connect an area of interest with imaging opportunities, spacecraft pointing, available power and data download. A request for many overlapping pictures can improve coverage while increasing storage and communications demand. Students therefore encounter a real systems problem: satisfying one request can constrain another, and a workable plan must respect the capabilities of the whole spacecraft.

NUS also describes later Galassia development work, including Galassia-5 integration, radio and environmental-test projects in its April 2026 showcase. Those records document engineering activity; they do not establish that every proposed successor has flown. The family’s lasting contribution includes both the measurements returned by completed missions and the practical skills built through designing, testing, operating and improving a satellite over successive student cohorts.