PearlAfricaSat-1: investigate a missing signal

PearlAfricaSat-1 was Uganda’s first satellite, developed within BIRDS-5 with Kyushu Institute of Technology and Uganda’s Science, Technology and Innovation office. JAXA described communications and Earth-observation demonstrations among the collaboration’s aims. The spacecraft traveled aboard Cygnus NG-18 in November 2022 and was released from Kibo on 2 December. The archive uses the title PEARLAFRICASAT-1. These milestones establish transport and deployment, not the achievement of every intended experiment.

The BIRDS-5 team’s March 2023 technical review reported that no signals had been received from its three satellites. After investigating with a ground test spacecraft, the team did not identify a clear cause. That is an important engineering result to preserve: the evidence established a communications problem, while the reason remained unresolved. A suspected component should not be turned into a proven explanation.

Imagine a receiver hears a known reference spacecraft but hears nothing from a new satellite. This control test supports the conclusion that the receiving chain works for the reference signal. It does not prove that the new spacecraft has power, that its antenna deployed, or that the receiver is configured correctly for its particular transmission. Each of those possibilities calls for additional evidence.

Now suppose three ground stations make four attempts each, with no confirmed reception. That is twelve unsuccessful observation attempts, not twelve independent spacecraft failures. The stations may share the same tracking estimate or decoding settings, and all attempts may be affected by the same onboard condition. Count the observations accurately and record the assumptions they share before treating repetition as independent confirmation.

Do not confuse observation count with cause

A useful investigation links each hypothesis to a test and a result. Mark a cause as supported, weakened or still unresolved. Reproducing a fault on ground hardware can make an explanation more plausible, but the ground setup may differ from the flown unit. Failure to reproduce it is also informative without proving that the event could never occur in orbit.

PearlAfricaSat-1’s story therefore includes both a national first and the difficult work of interpreting a silent spacecraft. The launch photo shows the shared transport vehicle; the CubeSat is enclosed and cannot be inspected in that scene. Training, assembly records and investigation methods can support future missions, while the original operational evidence remains part of the history. Learning from the mission means keeping both achievements and limits visible.