Blog
Fisher Space Systems LLC
Viper Rocket Trike
Updated Dec 2024
"Simplicity is the ultimate sophistication."
- Leonardo da Vinci
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Copyright (c) 2021 Jerry F Fisher
http://creativecommons.org/licenses/by-sa/4.0/
Copyright (c) 2021 Jerry F Fisher
01-30-2024: This month, I worked on the flight system. I moved the servos and control rods to the vertical and horizontal stabilizers and attached them to the frame. The total mass as of this month is ~ 1056 gm. This leaves 446 gm for the paraglider, canopy, and nosecone. Read more in the Jan EOM Report.
02-29-2024: This month, I continued work on the flight system. I finished the paraglider, forward strut, equipment bay, and nosecone. The total mass as of this month is ~ 1190 gm. This leaves 310 gm for the canopy and release mechanism.
03-31-2024: This month, I continued work on the flight system. I finished the canopy and release mechanism. The canopy is made of PLA and has four post that fit into spring loaded sockets mounted on the frame. High resistance wire is used as a fuse releasing the canopy when a high current passes through the wire. The mass of the canopy and release mechanism is ~ 125 gm, less than half of my mass allotment of 310 gm for the canopy and release mechanism. Read more in the Mar EOM Report.
04-30-2024: This month, I continued work on the flight system. I assembled the entire rocket glider. The final mass is ~1.2 kg. This leaves 300 gm for the HTP oxidizer and PLA/KMnO4 fuel. I performed a dry run for launch. Everything checks out. All systems are go for launch next month.
05-31-24: This is the first launch of the MkI Viper. The MkI Viper is powered by a hybrid rocket motor. The oxidizer is ~ 85% hydrogen peroxide (HTP). The fuel is polylactic acid (PLA) infused with potassium permanganate (KmNO4). The total mass of the MkI Viper is ~ 1.4 kg including ~ 150 gm of propellants. As such, the Viper meets the requirements for a class I rocket as defined by 14 CFR 101.22(a). In this video, the propellant load was 50 ml of ~ 80% HTP, 2 ml of Ethanol, and ~ 5 gm of PLA/KMnO4. Total mass of propellant was ~ 78 gm. Flight control is via an RC transmitter and receiver. On this flight, the controls were left in the neutral position to view the take off without guidance. The video shows the Viper yawing to port and pitching down. This can be corrected by rearranging the mass. The objective now is to learn to fly.
06-30-24: This month marked the second launch of the MkI Viper. The liftoff mass was ~ 1.45 kg with a propellant mass of ~ 93 gm. Ignition occurred in less than 0.1 seconds and liftoff occurred in ~ 0.3 seconds. I had active control using a transmitter and receiver. The Viper flipped a few times as it cleared the rail guide. I regained control momentarily. However, burn through at the nozzle inlet caused the Viper to spin out of control and crash into the ground. It was an exciting six seconds. Read more in the Jun EOM Report.
07-31-24: This month marked the third launch of the MkI Viper. The liftoff mass was ~ 1.4 kg which includes a propellant mass of ~ 94 gm. Ignition occurred in less than one second. I had active control using a transmitter and receiver. The Viper yawed to port and pitched up (as opposed to pitching down on the last launch) as it cleared the rail guide. On comparing the two launches, it is clear that the center-of-mass was below the thrust vector (pitch down) on the last launch and above (pitch up) the thrust vector on this launch. I feel I'm getting a handle on CM calculations with predictable results. Read more in the Jul EOM Report.
08-31-24: This month I had three launches of the MkI Viper. I replaced the PLA canopy with the fiberglass canopy and calculated the center of mass to be at 3.4 cm with the thrust vector at 3.5 cm. The MkI Viper cleared the rail guide, continued to about 30 feet before pitching up, did a few flips, and landed ~ 15 feet from me. After careful review of the videos from this month, I surmise that the thrust vector and center of mass are aligned. Also, I believe it has become an issue of air drag. The Viper clears the rail guide and begins to pitch up as it is gaining velocity. I plan on initializing the flaps in the down position to counter the air drag on top. Aug EOM Report
09-30-24: This month I had two launches of the MkI Viper. Initializing the flaps down on the first launch did not compensate much for the pitching up. I made my nose cone longer in the second launch but had an equipment failure, so no data. I printed a fuselage mold out of PLA, glued the pieces together, and sanded and waxed the surface. I used the mold to make a fiberglass fuselage. After curing, the fiberglass fuselage popped right out of the mold. The results were better than expected. Sep EOM Report
10-31-24: This month I had two launch attempts of the MkI Viper. There was a leak at the propellant tank connection on the first attempt and the engine did not ignite on the second attempt. Also this month, I made a port and starboard fiberglass fuselage with a raised rib down the center. This increased the strength with no mass added while improving the streamline of the Viper. Oct EOM Report.
11-30-24: This month I moved the thrust vector up by 1.0 mm to bring it more in line with the center of mass. Also this month, I increased the size of the vertical and horizontal stabilizers tripling the available surface area. Finally, I trimmed the starboard and port panels thus stream lining the MkI Viper.
02-29-2024: This month, I continued work on the flight system. I finished the paraglider, forward strut, equipment bay, and nosecone. The total mass as of this month is ~ 1190 gm. This leaves 310 gm for the canopy and release mechanism.
03-31-2024: This month, I continued work on the flight system. I finished the canopy and release mechanism. The canopy is made of PLA and has four post that fit into spring loaded sockets mounted on the frame. High resistance wire is used as a fuse releasing the canopy when a high current passes through the wire. The mass of the canopy and release mechanism is ~ 125 gm, less than half of my mass allotment of 310 gm for the canopy and release mechanism. Read more in the Mar EOM Report.
04-30-2024: This month, I continued work on the flight system. I assembled the entire rocket glider. The final mass is ~1.2 kg. This leaves 300 gm for the HTP oxidizer and PLA/KMnO4 fuel. I performed a dry run for launch. Everything checks out. All systems are go for launch next month.
05-31-24: This is the first launch of the MkI Viper. The MkI Viper is powered by a hybrid rocket motor. The oxidizer is ~ 85% hydrogen peroxide (HTP). The fuel is polylactic acid (PLA) infused with potassium permanganate (KmNO4). The total mass of the MkI Viper is ~ 1.4 kg including ~ 150 gm of propellants. As such, the Viper meets the requirements for a class I rocket as defined by 14 CFR 101.22(a). In this video, the propellant load was 50 ml of ~ 80% HTP, 2 ml of Ethanol, and ~ 5 gm of PLA/KMnO4. Total mass of propellant was ~ 78 gm. Flight control is via an RC transmitter and receiver. On this flight, the controls were left in the neutral position to view the take off without guidance. The video shows the Viper yawing to port and pitching down. This can be corrected by rearranging the mass. The objective now is to learn to fly.
06-30-24: This month marked the second launch of the MkI Viper. The liftoff mass was ~ 1.45 kg with a propellant mass of ~ 93 gm. Ignition occurred in less than 0.1 seconds and liftoff occurred in ~ 0.3 seconds. I had active control using a transmitter and receiver. The Viper flipped a few times as it cleared the rail guide. I regained control momentarily. However, burn through at the nozzle inlet caused the Viper to spin out of control and crash into the ground. It was an exciting six seconds. Read more in the Jun EOM Report.
07-31-24: This month marked the third launch of the MkI Viper. The liftoff mass was ~ 1.4 kg which includes a propellant mass of ~ 94 gm. Ignition occurred in less than one second. I had active control using a transmitter and receiver. The Viper yawed to port and pitched up (as opposed to pitching down on the last launch) as it cleared the rail guide. On comparing the two launches, it is clear that the center-of-mass was below the thrust vector (pitch down) on the last launch and above (pitch up) the thrust vector on this launch. I feel I'm getting a handle on CM calculations with predictable results. Read more in the Jul EOM Report.
08-31-24: This month I had three launches of the MkI Viper. I replaced the PLA canopy with the fiberglass canopy and calculated the center of mass to be at 3.4 cm with the thrust vector at 3.5 cm. The MkI Viper cleared the rail guide, continued to about 30 feet before pitching up, did a few flips, and landed ~ 15 feet from me. After careful review of the videos from this month, I surmise that the thrust vector and center of mass are aligned. Also, I believe it has become an issue of air drag. The Viper clears the rail guide and begins to pitch up as it is gaining velocity. I plan on initializing the flaps in the down position to counter the air drag on top. Aug EOM Report
09-30-24: This month I had two launches of the MkI Viper. Initializing the flaps down on the first launch did not compensate much for the pitching up. I made my nose cone longer in the second launch but had an equipment failure, so no data. I printed a fuselage mold out of PLA, glued the pieces together, and sanded and waxed the surface. I used the mold to make a fiberglass fuselage. After curing, the fiberglass fuselage popped right out of the mold. The results were better than expected. Sep EOM Report
10-31-24: This month I had two launch attempts of the MkI Viper. There was a leak at the propellant tank connection on the first attempt and the engine did not ignite on the second attempt. Also this month, I made a port and starboard fiberglass fuselage with a raised rib down the center. This increased the strength with no mass added while improving the streamline of the Viper. Oct EOM Report.
11-30-24: This month I moved the thrust vector up by 1.0 mm to bring it more in line with the center of mass. Also this month, I increased the size of the vertical and horizontal stabilizers tripling the available surface area. Finally, I trimmed the starboard and port panels thus stream lining the MkI Viper.
