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Fisher Space Systems LLC

Viper Rocket Trike

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Updated May 2021
01/27/2021: This is a test of 3, 3D printed poly lactic acid (PLA) fuel core segments with 20% hexagon infill infused with potassium permanganate (KMnO4) at high pressure and temperature. Each segment is 5 cm long and 1.7 cm in diameter making the total length 15 cm. The mixing chamber is preheated for about 10 sec using a high resistance glow wire. Ninety percent hydrogen peroxide (HTP) is introduced into the fuel core under a pressure of 120 psi by opening a normally closed solenoid valve. The KMnO4 catalyzes the HTP producing the initial temperature and pressure for the thermal environment. Once the high temperature environment is established, thermal and catalytic decomposition of HTP continues.

04-08-2021: This is a repeat of the 01-27-2021 test but with a 1/4" stainless steel mist injector with a 1.0 mm diameter orifice, a 3.0 mm fuel core wall thickness, L/D=12.5 (vs 2.0 mm, L/D=10.5 in 01-27 test), and 85% HTP (vs 90%). Combustion instabilities seem to be under control due to a higher pressure drop across the injector. The net positive thrust occurs at the end of the video corresponding to the erosion of the graphite nozzle throat from 3.6 mm to 5.2 mm. The increase in throat diameter reduces chamber pressure and increases mass flow rate resulting in a net positive thrust. Net positive thrust occurred for ~2 sec at a thrust of greater than 12 N. PLA fuel core segments were infused with potassium permanganate at high temperature and pressure.
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"Simplicity is the ultimate sophistication."
- Leonardo da Vinci
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