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2021 Hack-A-Sat DEFCON Space Security Challenge CTF Qualifiers Writeup - Linky

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Linky was an RF math problem, introducing the link-budget algorithm and getting contestants to calculate missing parameters for the operation of the radio link. Years have passed since our satellite was designed, and the Systems Engineers didn't do a great job with the documentation. Partial information was left behind in the user documentation and we don't know what power level we should configure the Telemetry transmitter to ensure we have 10 dB of Eb/No margin over the minimum required for BER (4.4 dB) . Upon connecting to the target port and presenting token, you're presented with a TUI of sorts: _ _ _ | | (_)_ __ | | ___ _ | | | | '_ \| |/ / | | | | |___| | | | | <| |_| | |_____|_|_| |_|_|\_\\__, | |___/ .-. (;;;) \_| \ _.--l--._ . \ | `. .` `.\ | .` `. .` `\ | .` `. / __ \.|.` __ \/ | ''--._ \V _.--'' | | _ (") _ |

2021 Hack-A-Sat DEFCON Space Security Challenge CTF Qualifiers Writeup - Take out the Trash, pt. 1

Take out the Trash, pt. 1 "A cloud of space junk is in your constellation's orbital plane. Use the space lasers on your satellites to vaporize it! " Take out the trash involved parsing two sets of orbital elements, one for satellites "under our control" with lasers to shoot trash, and a second, containing the trash to be shot. They were provided in the now-familiar Two Line Element format. We were also given two parameters that needed to be taken into consideration when shooting upon the given trash: The lasers have a range of 100 km and must be provided range and attitude to lock onto the space junk. Don't allow any space junk to approach closer than 10 km. The first order of business for solving this challenge will be establishing where the two constellations are at any given moment. In the past, we've used both PyEphem and SkyField to load TLE sets and determine positions. Given the deprecation warnings on PyEphem, and not requiring m