How do you transmit data when there’s 205,000 people trying to access the same mobile network in a field? Satellites, of course! After facing dilemmas of tracking the staff shuttles at a major UK festival, we decided to look at other options and discovered some cheap Iridium satellite constellation hardware on eBay. When they arrived, we surveyed what we had purchased, discovered it was ex-Ministry of Defense hardware, and hasn’t been scrubbed properly. After getting a new pair of trousers and making the relevant disclosures, we worked to reverse engineer the hardware and get some usable data transmitting into space (and back down). This involved dumping the firmware of the chip, and stepping bit-by-bit through the memory to understand what was happening, as well as a few casual emails to defence contractors. Getting airtime for satellite hardware was also a challenge, and working around the intricacies of Iridium Short Burst Data. Furthermore, we’ve developed the concept into an interactive map that overlays the realtime position of the tracker, and gives speed and heading data.