Yesterday, we flew our fullscale rocket in Bayboro, NC for the second time, this time with a running roll control device and balloon payload. The rocket, now painted completely black, went up around 4793 feet, under our target of 5280, but it was a windy day and the roll control flywheel was not working perfectly. This time, both cameras worked and the altimeters reported similar figures for apogee. While the balloon payload's connection to the nose cone broke, and the roll control flywheel needs some touch-ups, the flight was successful in that everything essential to a safe flight worked correctly. Below are images and pictures from the launch.
Because our first flight was too high (5498 ft), had a smaller mass, and no ballast or paint, we chose to fly our rocket again with a K1000T motor. This flight was with 12 oz ballast and paint. The mass of the rocket increased to 23.8 lbs. While our simulations predicted 5283 ft for vertical launch with no wind, the actual launch was about 10 mph wind angled a few degrees into the wind, away from the crowd. Apogee was at least 1500 ft into the wind according to our GPS data. The most precise reading for apogee was 4793 ft (due to the significant arc into the wind). In conclusion, the rocket is stable ballasted from 22.6 lb to 23.8 lb. The location of ballast (forward of CG) improves the CG-CP stability margin. Unless there are objections, we intend to fly at Huntsville ballasted to about 23.8 lb.
In addition, the RAD (roll control device) was operational. Communication with the new VESC motor controller was implemented two days before the flight, so we did not have the PID algorithm optimized. We experienced significant oscillation in the roll position. We are working to improve this for the next flight. The roll oscillation is clearly seen in the videos. GPS downlink was working. See flight path below. The balloons disconnected from the nose cone. Possibly a poor knot was used. We are updating their knot tying skills. Lastly, dual deploy recovery worked fine.
More pictures and videos after you click "read more"
This blog will be updated once a week over the course of the 2018-2019 school year, detailing our progress. It will be signed at the end by a member of the team.