High-power two stage rocket model HERKULES launch at XII. Annual Sprin' Meet o' Model Rocketry - SVOJEK May 6, 2017 Three on-board camera recordings and external camera slow motion video. Flight safety control by on-board elektro-mechanical gyro-vertical, akcelerometr and electronics. Picturesque sprin' time countryside at t' foothills o' Krkonoše Mountains.