ICSP: turn a user’s need into a satellite requirement

Bhutan’s GovTech agency identified the In-Country Satellite Project, or ICSP, at its November 2024 Space Forum. Pooja Lepcha’s technical presentation describes a six-unit Earth-observation spacecraft development effort, building on experience from BHUTAN-1 and India–Bhutan SAT. The intended shift is toward greater local responsibility for designing and integrating the system, alongside the facilities and skills required to support that work.

The presentation identifies uses such as crop and vegetation monitoring, water observations, disaster analysis and urban expansion. It also includes a forecast launch year. A forecast is not a flight record: the cited materials establish the development project and its aims, not a completed ICSP launch. The useful question is how the team translates each desired application into a testable requirement.

Imagine a square scene six kilometers on each side. With fifteen-meter ground sampling, it contains four hundred samples per side, or 160,000 pixels. At five-meter sampling, the same scene contains twelve hundred samples per side, or 1,440,000 pixels. The finer version has nine times as many pixels, even though the spacing improved by a factor of three.

If each scene uses three bands and two bytes per band per pixel, the uncompressed files would contain 960,000 bytes and 8,640,000 bytes respectively. These invented settings are not ICSP specifications. They illustrate why a camera choice affects memory, processing, downlink time and energy. Compression may reduce the transmitted size, but its settings and effects on the intended measurements must be assessed.

Finer sampling increases a scene’s data demand

A requirement such as “produce good images” leaves too much undefined. A more useful version identifies the target feature, spatial sampling, calibration needs, allowed pointing error and deadline. Each clause should have a verification method: analysis, inspection, demonstration or test. Passing an electrical interface test does not establish image quality, just as a sharp laboratory picture does not establish orbital pointing stability.

Local integration capability includes controlled assembly, handling procedures, configuration records and tests repeated after changes. The team can track what was verified on a component, on an integrated engineering model and on the final flight configuration. A purchased component still needs to work inside the assembled system. Developing a satellite at home therefore means building the process that produces reliable evidence, not assuming every individual part must also have been manufactured locally.