SpaceX appears to encrypt Falcon 9 telemetry after intercepting radio amateurs

SpaceX seems to have started applying encryption to make the Falcon 9’s telemetry and video feed no longer visible to third parties. The move follows media attention for radio amateurs who intercepted the telemetry.

Derekcz reports on Reddit that the video broadcast of the Falcon 9 rocket contains only noise, a sign that the stream is encrypted. For several weeks, Derekcz and user Xerbot were able to decode the missile’s video stream and publish images. The radio amateurs also managed to intercept telemetry and convert it into plain text.

Falcon 9 signal in the S band intercepted by derekcz and xerbot

They used software-defined radio using a HackRF module and a satellite dish to intercept the downlink at 2232.5MHz. For the demodulation they used GNU Radio. SpaceX has not given any reason for the decision to encrypt the stream. Derekcz points out that SpaceX had been sending the data unencrypted for more than a decade. He therefore does not think that the decoding by radio amateurs is the basis of the decision, but rather the publicity and incorrect reporting about it.

He previously reported that it was not sensitive data from the Falcon 9 and that the Starship’s telemetry was already encrypted.

Images from the Falcon 9 video feed that derekcz managed to obtain