Hacking yourself a satellite - recovering BEESAT-1
In 2013, the satellite BEESAT-1 started returning invalid telemetry, rendering it effectively unusable. Because it is projected to remain in orbit for at least another 20 years, recovering the satellite and updating the flight software would enable new experiments on the existing hardware. However, in addition to no access to telemetry, the satellite also has no functional software update feature. This talk will tell the story of how by combining space and computer security mindsets, the fault was correctly diagnosed without telemetry, software update features were implemented without having them to begin with, and the satellite was recovered in September of 2024.
In 2009, BEESAT-1 was launched into low earth orbit as the first 1U CubeSat of Technische Universität Berlin. In 2011, the satellite started returning invalid telemetry data. After a short amount of time spent diagnosing the issue, operators switched to the redundant on-board computer, which initially resolved the issue. However in 2013 the issue reoccurred on the second computer. With no other on-board computer available to switch to, operations largely ceased besides occasional checks every few years to see whether the satellite was still responding to commands at all.
A recovery of BEESAT-1 back into an operational state was made particularly attractive considering that due to its higher orbit, it is currently estimated to remain in space for another 20 years or more, while many of the other spacecraft of the BEESAT series have since burned up in the atmosphere. Additionally, the spacecraft is equipped with a number of sensors and actuators which were not fully utilized during the primary mission and could be used in an extended mission. However, to fully utilize all the available hardware on the spacecraft, a software update is required. Unfortunately, the software update functionality was not completed at the time of launch and as a consequence is in a nonfunctional state. An alternate solution must be devised.
