Oklahoma State University’s AIAA High-Power Rocketry Team
has had a successful first launch!
Throughout last week, the paint job was completed and
recovery system installed on the club’s rocket. During that time, I was also
hard-pressed to complete assembly of the rocket I was using to attempt my Level
1 Certification. The majority of that rocket came together the Friday and
Saturday leading up to Sunday’s launch date in Tulsa.
I ran into all kinds of problems with the kit I was using.
The center of aerodynamic pressure was located far too close to the center of
gravity (it is important for flight stability that the CG be one body-tube
diameter forward of the CP), and the recommended solution here is to mix lead
shot and epoxy and pour them into the nose cone. The problem was that I needed
almost a pound of weight in the nose cone to make the rocket stable. It was a
real pain just trying to get four ounces of lead and epoxy through the nosecone
hole, and only about three and a half ounces actually made it to the nosecone
tip. A friend suggested pouring a bunch of Gorilla Glue and shot together and
shaking it all around so that the glue will expand overnight. Cut to the next
morning, the day of the launch when I examine that handiwork, I hear the
tinkling of tiny BBs inside the nosecone as all the gooey Gorilla Glue gave way
to hundreds of loose shot pellets. Plan B involved salvaging another, longer 4”
nosecone from an old kit lying around the lab which actually turned out to make
the whole rocket more stable which was a nice surprise.
Another issue included the ten second delay grain which
would be too short given the projected flight profile of this rocket on my
intended motor. By winding masking tape around a 3/16” drill bit to create a
depth stopper, I drilled into the delay grain just 3/32” to take off about
three seconds of the delay so that during flight, the parachute would deploy
seven seconds after launch rather than ten like usual.
Anyway, on Sunday morning sixteen members of our team showed
up at the lab where we agreed to meet. In five vehicles, we all carpooled and
headed out to Leonard, OK toting two large rockets, half a dozen motors, and
lots of tools. Upon arrival, it was a beautiful day in the mid-seventies and
light breezes in directions that didn’t include lots of trees.
The day’s turnout included hundreds of people, as well as a
team of middle school students who prepared numerous small science experiments
to launch inside a massive-diameter rocket flying on an M motor. The first
launches went well and wind would not appear to be an issue on that day. As I
prepared for my certification flight, the club’s prefect wouldn’t allow me to
launch given that my CG and CP were still too close together. I was frustrated
because this was the very issue I thought I’d resolved, but fortunately this
time, I had the help of more than a dozen engineering students to assist me in finding
a way to add weight to the front of the rocket. We began zip-tying wrenches and
bolts to the nosecone, but even a pound of those still didn’t cut it. My former
roommate had the solution: a 34mm impact socket he used for repairs on his
truck. The thing weighed twenty ounces and once zip-tied to the nosecone, my
problem appeared resolved, and I was good for launch.
Skipping through another hour of waiting in line, having my
rocket inspected for the umpteenth time by officiating rocketeers, paying the
launch fee, and waiting for countless other Estes rockets to be launched, I was
able to get mine on the pad. I didn’t feel nearly as anxious as two months ago,
but due to impatience, I just really wanted to get it over with.
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| Credit: Turner Action Shots |
The flight went great. At a launch weight of six pounds, the
short flight on an Aerotech H250G was nothing impressive, but it landed only a hundred
feet behind the line of vehicles in soft soil: dirty, but without damage. It
passed inspection, and the club’s prefect congratulated me on the certification
as did the OSU team and several spectators along the way back to our work site.
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| Mach Wave I at liftoff via GoPro |
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| Credit: Turner Action Shots |
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| Credit: Turner Action Shots |
My mother and sister happened to be coming to Oklahoma that
day, and shortly after my certification flight, they arrived at the launch site
as well. It was wonderful to see them again, and they got to see the flight of
our club’s rocket as the sun began to sink near the horizon. It was critical
that I achieve my Level 1 Certification beforehand because that would allow me
to be the responsible flyer for our club’s rocket on a high-power motor.
The club’s rocket, It’s Trivial, also flew flawlessly.
While not especially high in altitude (they also had to add weight to combat
the same CG CP issue I had), it went great, and that flight will serve as the
moral foundation for building (and flying) higher.
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| It's Trivial on the launchpad |
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| Anticipating Launch |
The reasoning behind the naming of “It’s Trivial” is from the Compressible Fluid Flow professor whom many of us have for an instructor. He’ll finish an extensive derivation of Reynold’s Transport Theorem or something else and brush it off saying, “This is all very simple high school math, it’s trivial.” Additionally, since this was a kit build and not especially difficult to do, the trivial designation is appropriate. We hope to continue naming our rockets based on other professor’s sayings.
Click here for the link to OSU's AIAA Facebook page that has a really nice video with photos and clips highlighting our launch date! AIAA did a really nice job putting this one together.
We all had a wonderful time on Sunday, and we look forward to our launches in the future. Thank you for reading, and I can’t wait to share more of our progress soon!
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| Oklahoma State University AIAA High-Power Rocketry Team (not all pictured) |
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