Mini Falcon 9 uses NASA software

[T-Zero Systems] has been working on its Falcon 9 rocket model for a while now. It’s an impressive model, complete with thrust vectoring, a microcontroller that follows a predetermined flight plan, a working launch pad and even legs to attempt vertical landings. During his first tests of his model, however, there were some problems with the control system software he wrote, so he’s back with a new system that borrows space shuttle software.

The first issue to address is gimbal lock, a problem that occurs when two axes of rotation become aligned during flight, causing erratic motion. This is especially difficult because this model does not have the ability to control body roll. Solving this problem using a quaternion instead of Euler angles involves a lot of math, provided by libraries developed for use on the space shuttle, but with the added efficiency improvements the new software runs at a much faster pace than before. Unfortunately, the new software had a bug that prevented the parachute from opening, which was only discovered after launch.

There’s also a lot going on in this build behind the scenes, like the test rocket engine used to test the control system, which is actually two counter-rotating propellers that can be used to model the thrust of an engine without actually ignite anything on fire. There’s also a separate video outlining a test method that validates the new hardware with data from previous launches. And, if you want to take your model rocket further in a different direction, it’s always possible to make your own fuel as well.