February Launch Day

The spring semester is off to a good start. I’m thoroughly enjoying my classes, and the first rocket launch of the year took place this past weekend!

Katelyn Powell is the new director of the OSU Rocketry Team, and we got a team rocket in the air for the first time in a while. The launch day itself was brutally cold, windy, and overcast. Far from ideal conditions, but the team rocket flew great, and I did the second flight of my multistage project, Mach Wave II Stage.

Since I started doing high-power rocketry as a hobby on my own last year, in addition to the work the university team does, I’ve enjoyed the pre-flight preparations much more. Three days before the launch, I had all electronics wired together, completed a dress rehearsal of pad preparations, and had all the necessary equipment and gear packed well in advance of the launch. Unlike the last-minute scramble I got used to when finishing a team rocket, this kind of preparation is more enjoyable and exciting.

When we arrived at the Rocket Pasture this past Saturday morning, all I had to do was pack together my parachutes, mate the airframes, and confirm electronics functionality before I could take it out to the pad.

For the flight, my main objectives were successful recovery of both stages, a new separation method to break the stages apart mid-flight, and ignition of the sustainer (second stage). At 13 pounds, it was heavier than I originally expected, but I still had high hopes for this first flight of the full stack. The wind was of concern because if the second stage was tilted over too much before ignition of the sustainer motor, the on-board TeleMega flight computer would prevent that ignition event. This is an important safety consideration, because if something catastrophic had occurred with the booster, or the rocket tilted over too much (like in this case), it is dangerous to ignite a second motor if it is pointed anywhere but upwards.

The I284 booster motor ended up not being powerful enough. At launch, the rocket immediately began to tilt into the wind, and I knew right away the second stage wouldn’t light. This wasn’t a bad thing by any means; it was just a little underwhelming when it barely reached 1000 feet. The separation event occurred as expected and all parachutes deployed nominally. Both the booster and sustainer landed gently, and I had lots of good data to comb through. Video of the flight is here: https://youtu.be/NTG0KhMkU3s. 

Image courtesy Bob Phelan

The team's rocket, "Say What", image courtesy Bob Phelan

I had made a number of new modifications to the rocket from the previous flight, all of which passed now including patching 4 holes for a previously-used beeper, installation of an antenna radome on the sustainer, functionality of the team’s Jolly Logic chute release, functionality of my new TeleMetrum flight computer, and obtaining in-flight telemetry from two separate transmitters simultaneously from a single computer. This was also an exercise in launchpad preparations which is very valuable, as I intend to fly this rocket many times in the future. 

Altitude and velocity data from the TeleMega, EasyMini, TeleMetrum, and RRC3

GPS data from my TeleMetrum. Bullseye is launch, yellow is ascent, teal is drogue, blue is main.

Tilt angle (plotted in green) vs time. 18 degree max allow able tilt angle for 2nd stage limit exceeded less than 1 second into flight (red line). At T+4 seconds when it was programmed to ignite, the sustainer was tilted almost 35 degrees (purple line). 

Going forward, my biggest observations are to use motors with significantly more thrust at launch and scrub launches if winds are too high. I have confidence in the whole system, I just need weather to do its part too.