Danfe: reuse software without reusing every assumption

The Danfe project brought APN and Nepalese partners into a collaboration with the Institute of Space Technology for Economic Development at King Mongkut’s University of Technology North Bangkok. The project-team presentations describe a payload for Thailand’s three-unit Multi-Payload CubeSat Platform, or MPCP. Its objectives included investigating PX4, software developed for drones, and a compact computing-and-radio system.

The presentations document development work in 2023. Their forecast launch dates do not establish a completed flight, and the cited evidence does not provide a later verified launch outcome for this Thai collaboration. Keep it distinct from Danfe-II, Nepal’s subsequent payload aboard the UAE’s PHI-1 satellite. Similar technology and related names do not make their hosts or mission histories interchangeable.

Useful software often contains reusable pieces: message handling, sensor interfaces, scheduling and logging. Other pieces assume a particular environment. A drone controller may expect measurements or actuators that a small satellite does not have. Adapting a software framework therefore begins by identifying which parts are being reused, which are replaced, and what information each part expects.

For an invented test, suppose a control loop expects a sensor update every twenty milliseconds. A replacement interface supplies an update only every fifty milliseconds. The original loop runs at fifty updates per second, while the new input arrives at twenty per second. Running the old loop unchanged cannot manufacture the missing measurements. The team must specify how it handles data age and evaluate the effect on the intended experiment.

Check timing when software changes environments

A good test first supplies known inputs and checks expected outputs. Then introduce a delayed sample, a missing packet or a restart. Record whether the software notices the condition, enters a defined fallback and recovers correctly. A log should include timestamps and version information so a different engineer can reproduce the sequence. Merely showing that a program starts says little about its behavior when a dependency fails.

The spacecraft environment also adds thermal, power and radiation concerns that a desktop test cannot reproduce by itself. Distinguish software-interface tests, environmental tests and orbital demonstrations in the results. Danfe’s educational value lies in asking which parts of an existing system can be adapted and what new evidence that adaptation requires. Hardware shown only as a reference illustration should likewise not be mistaken for a photograph of the actual flight article.