https://stkwans.blogspot.com/2013/06/not-another-rocketometer.html

I got an Arduino Leonardo and a Sparkfun Pro Micro as breadboard models of the Arduino-based Rocketometer. Based on my experience with those, I conclude that the ATMega32U4 and the current bootloader are Not Ready for Prime Time, and Not Ready for Spaceflight. Further, I would have had to write my own USB Mass Storage driver anyway.