PRETTY DOOMed: The First Voice Command of a Satellite

Hej folks! These past few months I’ve been working on a project to send a voice command to a spacecraft, and I’m happy to say that it finally worked! On 27 July 2026, a radio amateur in Oslo pointed their antenna to space, spoke into a microphone, and a satellite in orbit heard its instructions to play DOOM! It is the first time a satellite has been commanded by voice.

I developed the processing pipeline that ran onboard ESA’s OPS-SAT PRETTY satellite. It captured the 1296 MHz uplink with a software-defined radio, narrowed and demodulated it, transcribed the speech with an onboard speech-to-text AI model, detected the command despite transcription errors, and launched DOOM. It then downlinked a postcard with the gameplay frame, the transcription, and signal diagnostics.

The operator spoke into the microphone: "LIMA ALFA FOUR OSCAR, PRETTY PLAY DOOM DOOM DOOM, PRETTY PLAY DOOM DOOM DOOM." The spacecraft captured this recording during the evening pass.

OPS-SAT PRETTY composed this postcard and downlinked it, transcription included. That is what the satellite made of the live human voice: imperfect, but the repeated DOOM trigger word still got through.

This was not a pre-scripted trigger. It was a spoken command sent over amateur radio, detected and acted on autonomously in orbit.

The Oslo Group of the Norwegian Radio Relay League ran the July campaign under the club call sign LA4O: the satellite detected the command from a synthesized voice on the morning pass, then from an operator speaking live into a microphone that evening. The campaign followed earlier link tests from Legnica, Poland. Everyone involved is credited in the acknowledgements, and the experiment would not have happened without them.

Links

• Project Page.
• GitHub Repository.
• Acknowledgements.
• Oslo Campaign Report.