Fisher Space Systems LLC

Viper Rocket Trike

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Updated May 2023
01-31-2023: My objective for 2022 was to launch a class I rocket glider (the Mk I Viper). However, after a few launch attempts, I realized I didn't have enough thrust to exit the rail guide at the required velocity for aerodynamic control. I needed more thrust. As such, I spent the rest of the year working on scaling parameters to decrease ignition time and increase thrust. I've narrowed the scaling parameters down to three; initial surface flux, length to diameter ratio, and initial throat diameter. Also, I've upgraded my rocket engine test stand with reinforced concrete walls and a steel test frame on one of the walls. Read 2022 EOY Report

01-31-2023: This month, I collected all of my data and entered it into a spreadsheet. After two years of scattered data, I saw a trend in the rocket engine testing. I've settled on a rocket engine using a nozzle throat diameter is 6.0 mm and the rocket engine thrust is ~ 22 N. Over the next several months, I plan to test this design for consistency of time to ignition and thrust. Jan EOM Report

02-28-2023: This month, I did three test using the same scaling parameters. Although, the performance results are not as consistent as I'd like, the initial thrust is ~ 20 N at ignition and climbs to ~ 25 N toward the end of the burn. Twenty Newtons at ignition may be enough for aerodynamic control of the rocket glider as it leaves the rail guide. As such, it is my intention to launch the Mk I Viper next month. Feb EOM Report

03-31-2023: This month, I worked on the MkI Viper rocket glider. I broke the glider into three sections; a forward section, a mid section, and an aft section. I moved the servos from the mid section to the aft section and connected them directly to the fins. This shifted the center of mass of the rocket glider aft. To compensate, I moved the battery pack to the forward section. Next month, I'll finish the forward and rear cowlings and work on the paraglider. Mar EOM Report

04-30-2023: This month, I continued my work on the Mk I Viper. The total mass of the Mk I Viper including the propellants is now ~ 1.456 kg which gives me a mass margin of only 44 gm. I attached the paraglider to the fuselage. The wing loading is ~ 0.8 gm/cm2. Next month, I'll tweak the design and hopefully, do some drop testing. Apr 2023 EOM Report
"Simplicity is the ultimate sophistication."
- Leonardo da Vinci
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Copyright (c) 2021 Jerry F Fisher
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