SpaceX has been successful for a lot of reasons — many of them related to government contracts and Business Stuff™ that is boring to those of us with technical mindsets. But SpaceX has developed a lot of very impressive technology, too. The most eye-catching of that might just be their use of thrust vector control (TVC), which is how they steer rockets by adjusting the direction of the engine thrust. That was difficult to achieve because it requires sophisticated and precise control, which is why it is so cool that Garrett R was able to implement TVC into his DIY Maverick flight computer.
Garrett developed Maverick for use with rockets that are like those Estes model rockets you built as a kid — just much, much more sophisticated and a lot more expensive. Those affordable model rockets sold by Estes and its competitors don’t have any active control. They have one engine and only fly straight upwards thanks to the fins that stabilize the flight. The rockets Garrett builds are different, because they have active control via SpaceX-style TVC. For that to work, the rocket needs a flight computer that can monitor its orientation and adjust the thrust vector in real-time.
Maverick does that and is a follow-up to Garrett’s previous design, called EVA. Maverick improves upon many of EVA’s shortcomings, such as floating inputs and an external bootloader that was difficult to program.
Garrett designed Maverick around an STM32F4 microcontroller, which is a popular choice with a lot of documentation and that is easy to work with. It also has an internal bootloader that is easy to reprogram. Maverick has inputs with pull-up resistors for reliability, all of the necessary power inputs and outputs, data inputs and outputs, and sensor connections.
Interestingly, Garrett chose to implement ultrawideband for positioning. That works using triangulation with multiple ground stations, measuring the time (and therefore distance) it takes to transmit a signal between those and the rocket. That isn’t yet proven and Garrett still needs to evaluate it, but it could prove to be more useful than GPS, which isn’t very precise.
At this point, Garrett has an assembled Maverick flight computer and he’s tested that on the ground. But he hasn’t yet put it to the real test of a rocket launch. That will be exciting to see, so be sure to subscribe to Garrett R on YouTube to see the results as soon as he posts the follow-up video.