NanoSatC-BR: turn small-spacecraft readings into evidence

NanoSatC-BR is a collaboration involving INPE and the Federal University of Santa Maria. Its missions combine student training, space-environment investigations and electronics experiments. NanoSatC-Br 1 launched in June 2014; NanoSatC-Br 2 followed in March 2021. The first used a 1U CubeSat — open definition format and the second a 2U format. These spacecraft belong to one development program, but they are separate flight articles with different configurations and histories.

INPE describes geomagnetic measurements as a scientific objective, including investigations associated with the South Atlantic Magnetic Anomaly. The program also tests electronics and techniques intended to tolerate radiation effects. A magnetometer — open definition measures a magnetic field; it does not directly count every energetic particle or establish that a circuit is immune to radiation. The scientific observation and the technology experiment require different instruments, records and interpretations.

Imagine a fictional magnetometer reporting a larger value during one orbital pass than during another. Before attributing the difference to a changing space environment, compare position, time, sensor orientation, calibration — open definition and the spacecraft’s operating state. A nearby electrical system can also affect a magnetic measurement. These are general measurement considerations, not a diagnosis of an observed fault on either NanoSatC-BR spacecraft.

A useful dataset preserves the reading together with the information needed to interpret it. If a sensor provides three components in the spacecraft’s coordinate system, comparing them with an Earth-based model requires the relevant orientation transformation. A numerical value without units or a timestamp is difficult to use reliably. Better documentation cannot repair every missing observation, but it helps reveal which comparisons are supported and which remain uncertain.

Connect the number to the measurement

INPE’s BR2 description includes instruments, electronics tests and a student-operated ground segment. It also retains a prelaunch date that was later superseded, illustrating why a project description should be paired with a dated flight record. Here the launch history is stated at month precision. Planned instruments describe the intended investigation; they do not automatically establish the amount or quality of data ultimately returned.

Suppose a fictional mission receives housekeeping telemetry — open definition but cannot complete its intended sensor campaign. It would be wrong to say that nothing communicated, and equally wrong to announce that the science objective was met. The team may still gain operational experience and identify useful engineering lessons. Keeping scientific, technological and educational outcomes separate allows a more informative account than a single success-or-failure label for the entire program.