Space reported that a satellite went knee-deep in the dead after a voice command from the ground activated the 1993 first-person shooter game in space.
The PRETTY cubesat—operated by a consortium that includes the European Space Agency (ESA)—was never originally intended to run the iconic video game.
TheOPS-SAT Space Lab managed the experiment on behalf of ESA. Radio amateurs made six unsuccessful attempts during passes over Poland and Norway between April and July before the seventh finally succeeded under the Oslo Group of the Norwegian Radio Relay League.
Eskil Hadland, a representative with the call sign LB6AJ, stated that they were radio amateurs with the emphasis on amateurs.
Hadland noted in a statement from Estonia’s Tanagra Space that satellite work was not something their club did and they had no budget for it, leading them to borrow a line wrongly credited to Pippi Longstocking: “I have never tried that before, so I should definitely be able to do that.”
The Norwegians spent 59 days and about 7,200 NOK, or roughly $775 including pizza, to reach the PRETTY satellite and modify its software to pick up a human voice. An unaltered transmission capture sent back to Earth on July 3 demonstrated that the audio sent upward could not be understood at all.
Further diagnostic work revealed the satellite receiver channel was far too wide to pick up the audio signal properly, which prompted a fix to narrow the channel.
Jon Bergli Heier, using the call sign LB9BJ, delivered the historic voice command on July 27 from a rooftop in Oslo. Spoken at night, the command included the phrase “PRETTY play Doom”. PRETTY picked up the transmission, transcribed the command using on-board voice recognition, and opened up Doom for a gameplay session.
The transmission relied on open-source tools including GNU Radio for signal processing and Sherpa-ONNX for speech recognition. PRETTY generated a postcard that included a frame of the gameplay, a transcription, and signal diagnostics while also transmitting its recording of Hadland’s command back down to Earth.
Tanagra Space supplied the software for the feat and noted that someone in distress at sea or in a remote area could one day transmit a mayday or help call over a radio. The hope is that a satellite could eventually use transcription and AI to alert rescue services and assist people stuck in remote zones.
Future spacecraft might also adapt this approach to radio frequencies for tasks outside of spoken words, such as detecting deep-space radio signals with an on-board AI sending only the most relevant data back to operators. For now, the Norwegian radio operators are celebrating the milestone, with Hadland remarking that their tiny ground station shouted at an ESA spacecraft and was heard.
