Back in February, we launched the first rocket ever made by Southern Illinois University twice, without fail. Once we had these two flights under our belt, we were inspired to fly larger rockets at higher speeds to greater heights.
This craving was to be satisfied by building an eight foot tall, four inch wide rocket to compete in the 2018 Argonia Cup. With less than 3 months to complete our project, it seemed like we didn’t have enough time or money. However, thanks to the extraordinary generosity of a few people that will be mentioned later, we were given the resources necessary to reach our goal. It was now on us to build the rocket.
The construction of our Argonia Cup rocket was underway. This process required countless hours sanding each fitting, measuring out holes for venting, rivets, and shear pins, calculating pressure changes, max velocities, and apogees as well as 3D printing specialized centering rings to ensure the fins were perfectly straight. While we were caught up in building the rocket, we lost sight of what the Argonia Cup actually required of us. We were building a rocket that would fly very high and very fast. The Argonia Cup is focused more on precision recovery. The competition requires reaching an altitude of 8,000 feet and then returning a golf ball as close to a predetermined location as possible.
Our early calculations were projecting an apogee in excess of 16,000 feet, so altitude was no worry. The problem was that we had not started building our recovery system. This recovery system was originally a spring-loaded quadcopter that would deploy at apogee and autonomously fly itself to the exact GPS coordinates of the target using an open-source flight controller. It seemed as though the closer we were to finishing the drone, an increasing amount of problems arose. How were we going to safely get the drone outside of the rocket? Will the drone’s internal electronic orientation be offset by the 15G’s of acceleration? How long will it take for the drone to stabilize itself? Will the drone be able to fly in strong winds? We were able to find solutions to most of these problems, however we could not solve all of them while also building a reliable rocket. We decided that instead of quickly building an expensive drone that we would not have time to test, we would ditch the recovery method all together.
Once we had our rocket ready to fly we gave it to our adviser Bob Baer to paint. His work speaks for itself and we are grateful for his assistance. With our newly painted rocket, we were about two weeks from the competition and needed to finalize travel details. We had planned to camp at the launch site, but when we checked the forecast, we saw a Friday night low of 19 degrees. We promptly made reservations for two nights in a hotel about 15 minutes from the launch site.
There were three things that I did not want to see happen at this competition. First, I did not want our rocket to land in a tree. Our second flight in February landed in a tree and took an hour and a half to retrieve. This worry was minimized when I shared it with the experienced flyers at the competition. One flyer said that of his 400+ launches, only 4 have landed in trees. Also, we were in the middle of a state that is famous for not having many trees. Second, I did not want to break the rocket. We had invested far too much time into the rocket to see it fail. Finally, and most importantly, I did not want to end up in last place. I am happy to say that of those three things, only one happened. As you can see in the pictures in this folder, we somehow managed to get our parachute tangled in the only treeline within eyesight.
We left for Argonia, KS at 9:00 am on April 6th. We arrived in Argonia at 7:00 pm that night. After a quick dinner at a local Mexican restaurant, we went to bed. We woke up the next morning around 6:30 and met up with our team’s mentor, Air Force Major Bryan Sparkman, and his friend Chris Maier for breakfast. After we ate, we drove 20 minutes to the launch site, appropriately named “The Rocket Pasture”. We started preparing for our first flight around 9:00 am and were ready to launch around 11:00 am.
Flight prep includes many important aspects. First, we had members Jinal Valand and Matthew Lunde prepare ejection charges for our rocket. These consisted of four grams of black powder packed into a sealed cardboard tube with an electric match at the bottom. The electric match is ignited by our altimeter, either at apogee to split the payload and booster sections or at 800 feet to release the main parachute. Since this rocket is substantially larger than our previous one, some extra precautions were taken. Our rocket had two independent PerfectFlite Stratologger altimeters, each wired to a charge in the front and aft portions. This ensured that even if one of our systems failed, we could still safely recover our rocket. Once we had the electronics ready to go, James Cabahug and myself assembled the motor. For this rocket we used a four grain Aerotech L1420 with a total impulse of 4,608 Ns. To put that into perspective, that motor is about seven times more powerful than our previous flight. As the motor was being assembled, Caleb Dushman packed our 58” parachute and fireproof chute protector. With the motor, electronics, and parachute ready, we were set to fly.
After mounting our rocket on the launch rail, we took a few pictures, backed up to a safe distance, and waited for the launch.
Three. This is it. A semester of hard work lead to this moment.
Two. I really hope I am not forgetting anything
One. With a thunderous roar our rocket screamed through the air.
Launching the rocket up is only half of the problem. The other half is getting it safely back down. With ears pointed skyward we waited in silence for a sound indicating a successful apogee event. A small pop was heard as we turned our heads towards the rocket’s smoky trail, squinting at the empty sky in hopes of making visual contact. No such luck. With our rocket out of sight, we relied on a small HAM radio tracker used for falconry to find it. An hour of searching passed before we heard a faint beeping indicating the direction of the rocket. The rocket was found! At the time, we thought it was about a mile and a half away from the target. We were too excited about recovering a successful flight to remember that we were not allowed to touch the rocket before an official measured the distance. By touching the rocket, we had disqualified this first flight from winning. It was not until we returned to the launch site that a mentor from Oklahoma State University informed us that not a single team besides us was able to reach the required altitude and land in a flyable condition. Teams had frozen parachutes, exploding motors, and broken fins. This slightly disheartened us but we were told by the officials that if no other team was able to land successfully, we would win. Thus we finished the first day of competition ‘technically’ in first place.
The second day strongly resembled the first. Except there was one difference. A sense of haste filled our heads as the weatherman predicted increasing winds all day with a chance for rain in the afternoon. The flight waiver opened at 9:00 am, so we made sure we were ready to fly exactly at 9:00 am to beat the wind. Our second flight went just as well as the first and was rather unaffected by the wind. Typically, the biggest problem with flying rockets in heavy winds is weathercocking. Due to the aerodynamic nature of rockets, they will weathercock themselves by a few degrees into the wind. This means that if a team is using a motor that will get them only slightly above 8,000 feet, they may not reach the required altitude. We, however, made sure this would not be a problem in the slightest and used a motor which is essentially the most powerful motor the competition allowed. Our thinking behind this was that since we do not have a recovery system, we probably will not win the competition, so we might as well go as high and as fast as we can.
Our rocket’s first flight reached 12,306 feet with a max speed of 1,090 mph – it landed 4,220 feet from the target and would have won the competition. Our second flight reached 11,941 feet with a max speed of 1,130 mph and landed 5,914 feet from the target. Oklahoma State University reached 8,998 feet and landed 5,069 feet from the target to win first place. Of the 8 teams in attendance, we were the only team to have two successful flights. We were one of two teams to have a single successful flight. Oklahoma’s winning flight took place on the second day of competition after they experienced a parachute failure on the first day, breaking two fins off of their rocket. They were able to drive back to their workshop that night, make repairs, and fly again the next day.
Considering we entered the competition with no recovery method besides 20 feet of caution tape acting as a streamer to keep decent vertical, ending up in second place is fantastic. As I said earlier, I could not be more proud and thankful for my team. We not only built two incredibly successful rockets, but they helped me develop my leadership skills and became some of my closest friends.
Without the help of Dan Welling and Air Force Major Bryan Sparkman, we would not have been able to learn the complexities of rocket building as quickly as we did. Both of these men have been flying rockets for decades and were generous enough to act as my mentors and answer my thousands of questions. Maj. Sparkman also attended the February launch with us.
I would like to thank all those that donated to our project. None of this would be possible without the financial support of our donors, in particular our Rocket Boosters:
Jerry and Roberta Ling
Barbra Dillow, in memory of Louise and Jim Biggs
Finally, the team and I extend our gratitude for supplemental funding from the Office of the Vice Chancellor for Research, the Office of the Chancellor, the Department of Mechanical Engineering, and the STEM Outreach Center.
If we are able to get second place with only one semester of work, imagine what we will be able to accomplish with an entire year. Enjoy the photos in this folder and if you have any questions about our project, or about joining our team, my e-mail is firstname.lastname@example.org.
Over and Out,
Rocketeers of Southern Illinois