This past weekend was the first competition for the Oklahoma
State University AIAA High-Power Rocketry Team! We competed against the
Mississippi State University Space Cowboys and the Saint Louis University
Rocket Propulsion Laboratory in the inaugural Argonia Cup, hosted by
Kloudbusters in Argonia, KS.
The objective of the Argonia Cup 2017 was to take a golf
ball payload to 8000 feet and recover the payload as close to the launch site
as possible using a single L motor or less. Upon registration in November, our
team dived into the project of the payload recovery system in January. I asked Nick
Foster to head the program based upon his experience and research with drones
and UAVs. Over the next three months, he and his team along with financial and
logistical help from Dr. Jamey Jacob and the Unmanned Systems Research
Institute (USRI), they developed an autonomous spring-loaded drone to fit
inside a 4” diameter rocket. Using GPS and several other sensors and
instruments, the drone would release itself from the rocket during the main
recovery deployment event, begin flight, and pilot itself to the launch site.
Most parts were 3D printed and all was made right here at the university.
Meanwhile, our rocket design and assembly teams worked on
the ascent vehicle to take the UAV to 8000 feet. We faced a sizable constraint
in that due to our financial situation, we were unable to purchase the
necessary reloadable motor hardware for most L motors (75mm hardware). Additionally,
there were no 75mm reloads even available for purchase. Therefore, we had to
fly on the most powerful 54mm motor available, a single-use L1000W. It would be
questionable if we’d even surpass 8000 feet, as simulations indicated the final
rocket weighing at 17.3 pounds would barely reach that altitude. We proceeded
nonetheless because simulations can frequently prove inaccurate, and we had no
other feasible options.
To maintain the tradition of naming our rockets after
professor quotes, this rocket, It Depends,
was named after our applied aerodynamics professor, Dr. Jacob. Why “It Depends?”
Because it is the answer to many of the questions he asks in class regarding
designing aircraft. “Should this aircraft have winglets? Well, it depends.” He
is the director of USRI and thanks to his help and financial support, we
purchased two motors for the competition in case we had the chance to fly a
second time.
We had most of the rocket completed in late March as the
Argonia Cup was originally scheduled for April 1st and 2nd.
Due to weather, it was postponed until April 8th and 9th
which gave our team an extra week to prepare.
However, no matter how much planning and work gets done
ahead of time, the final preparations will always be made 6 hours before
departing for a launch. We spent Friday evening of the 7th making
these final preparations and left the lab at 2:00 AM. I got all of an hour and
a half of sleep before waking up again to return to the lab. We had a good
group going with us including half of our team who would stay Saturday evening
to camp on the rocket pasture to see some more launches Sunday morning. This
worked out very well for us.
At 6:45 Saturday morning we loaded up the vehicles and were
on the road at 7. I rode with my former roommate and just before the Kansas
border, a wheel gave out, so we pulled over to have a look. He has done plenty
of work on his truck and recognized the problem to be a blown wheel bearing. We
called a friend of ours also heading to the launch, and he provided us rides
into Blackwell just a few minutes away to purchase replacement parts and tools
for the fix. After propping a jack upon several cinderblocks, we removed the
tire, brakes, and broken wheel bearing. The cylindrical bearings had been
smashed to bits. Unfortunately, upon replacing it with a new bearing, the bolt
threads stripped, so they made a second trip into town to buy new bolts. Once
they returned, we tried with the new bolts, but the stripped bolts also
stripped the threads of the brand-new wheel bearing. They made a trip to Ponca
City and an hour later returned with another $150 bearing. This time everything
worked, and five hours after pulling over, we were back on the road. Even
better, his truck now runs better than it has in a long time, so that was a
plus.
When not flying rockets, we can work on cars, too. |
Nic representing us with our t-shirts by the side of the road |
We arrived at the rocket pasture mid-afternoon and got a
status update from the rest of our team who arrived first thing in the morning.
We had one successful Level 1 certification flight and one unsuccessful one.
For the latter, the fiberglass V2 kit didn’t have a recovery deployment event,
so it lawn-darted from a thousand feet and the two-foot tall rocket buried
itself nose-first up to its fins in the soil. The whole thing splintered into a
dozen pieces, and the remains couldn’t be more spectacular. It is always
impressive how much energy there is in such a system when the recovery system
doesn’t succeed.
As for our Argonia Cup entry, the drone wasn’t where we
wanted it, so Nick returned to Stillwater for the evening to work on it more.
With two hours remaining in the day, we prepared our Spaceport America Cup test
rocket. It was the first rocket we launched in October, It’s Trivial, with an additional middle section containing our
airbrake. For this flight, an external switch initiated the mechanism on the
launchpad that oscillated moving fins to induce drag mid-flight. The final
product will be a PID-controlled design that will compute apogee and induce
drag in real-time. Anyway, this launch performed beautifully with the
oscillating fins operating throughout the entire flight. We know this because
we had an on-board video recording the whole thing.
Part of our Spaceport America Cup Team |
That successful test launch was a good way to cap off the
first day. As for our competition, both other teams launched their entries
Saturday. Mississippi State flew some 15000 feet and landed more than two miles
from the launch pad. Saint Louis flew more than 10000 feet and landed a mile
and a half from the site. Neither team had anywhere near the sophistication of
our autonomous UAV; theirs were little more than a parachute tied to a golf
ball. This statement is amusing after what happened to us the next day.
Half of our team returned to Stillwater Saturday. The rest
of us set up camp and drove to Wichita for dinner. Fizz Burgers was delicious,
and it felt refreshing to make a run into the city. When we returned to the
rocket pasture at 9:00, the Kloudbusters were sitting around a gas campfire,
and after I said hello, they said our team should join them around the fire. It
was a blast listening to their stories of the dumb things they’ve done and
others (especially college students) have done over the years. I’d say we’re in
good standing with them.
Team photo Saturday afternoon |
After the short night previously, it was a real treat to
sleep a full eight hours outdoors. A member of our team made us pancakes and
bacon for breakfast, and we got the rocket ready during that time as well,
anticipating a mid-morning launch and returning home by early afternoon. This
did not happen.
Sunrise |
The drone was fine, but our altimeter arming switch broke,
so we had to solder a new one and affix it to the sled. Once that was complete,
we learned that our two tracking systems operate at the same frequency as the
drone, and Nick was afraid interference from the trackers would cause the drone
to malfunction. This meant we had to ditch both trackers and fly the rocket
blind into dense, low-level cloud cover. We would however get a GPS reading
from the drone throughout, but the drone and rocket would separate on descent,
so not even that was completely reliable. We sent out two extra tracking teams
at various places down the road and with radios, we could communicate with
those at the launch site.
It Depends,
weighing 19.5 pounds at the pad, took off the pad just after 1:00 in the
afternoon, disappearing into the clouds in seconds. Without tracking, we’d have
to hear the GPS readout and hope we could see it as it reentered below the
clouds. My friend happened to see parts of a rocket land with a thud in the
wheat field in front of us. Those at the launch site confirmed that was in fact
our rocket, and what remained of it was lying in that field.
We headed in and discovered our very muddy and partially damaged rocket. The aft airframe was filled with six inches of wet soil and stuck upright out of the ground. The sixteen-inch nosecone was buried to its base level with the ground. The drone was smashed to bits. It took a while to figure out what went wrong: the main ejection charge never fired (altimeter lost power), hence the main chute and drone never deployed causing the connected halves of the rocket to tumble down from 8000 feet. The splintering of the nosecone and drone occurring upon impact with the ground rather than an issue during flight. We found out also that even if everything had gone smoothly, we wouldn’t have had a qualifying flight because the whole rocket flew just shy of 8000 feet.
![]() |
Drone remains |
As we’re analyzing the wreckage, my friend pointed out that
the only component of the rocket truly damaged was the nosecone. We had another
nose from It’s Trivial, the rocket we
flew yesterday. Upon the realization that we could clean mud from the rocket
and reconfigure the recovery system, we could fly a second time using the extra
motor we purchased. The catch was we had two hours to do so before the
competition ended.
What ensued next was a blur because we did so much in those
two hours. We ditched the drone payload to save weight, and reset the altimeter
to prepare for this flight. We used the plastic nosecone from It’s Trivial, but because there wasn’t a
secure point of attachment, we were uncomfortable affixing the main parachute
to that nosecone. Nick came up with a clever idea to use the Jolly Logic Chute
Release altimeter to deploy the main rather than by black powder. This nifty
gadget uses a rubber band and pin to wrap around a parachute and then at a
certain altitude the pin releases allowing the parachute to unfurl. This would
allow us to put the drogue-ejected shock cord (to be deployed at apogee) in the
same rocket section as the main parachute, all aft of the altimeter bay.
One problem with this Jolly Logic altimeter (or Jolly
Rancher as the Kloudbusters call it) is that we’d never tested it and couldn’t
guarantee it would work (especially after taking the hard hit with the ground
earlier that afternoon). While we’re preparing It Depends for flight, we had a team prepare our small rocket, Dynamic System, for flight to test the
Jolly Logic. So, we flew another rocket to test the component we’d put in our
competition entry, all over the course of a half hour. As Dynamic System took off, it separated properly, but the main didn’t
deploy. Turns out the chute release worked, the parachute just got tangled.
That was all we needed, and we could make the final
adjustments for It Depends. We got
the rocket out on the pad, and this time we had trackers installed, so we
weren’t worried about losing sight of it this time. I went out with the
tracking team, and just thirty minutes before the launch window closed for the
competition, It Depends roared off
into the breezy, blue Kansas sky.
Standing
in my friend’s truck bed, we kept our eyes peeled for the rocket halves and
after some time, I happen to look behind us and see it tumbling just a short
way away and at 600 feet, the main unfurled, gently dropping our rocket into a
field. We were ecstatic because we knew we’d gone over 8000 feet and were far
closer the launch site than any other team.
We recovered the rocket to hear the altimeter beeping out
8744 feet. Kloudbusters verified our location to be 0.7 miles away; next
closest was SLU at 1.5 miles away. With that, we had won the Argonia Cup, and we
returned to the rest of our team blaring “Eye of the Tiger” as we pulled up.
We took photos with the Argonia Cup trophy and were
presented our winnings: $500 cash and an Altus Metrum TeleMega $400 altimeter.
Bob Brown, the Kloudbusters club prefect, told me congratulations, and he was
glad he didn’t have money on this because he didn’t think we’d be able to pull
off a second flight, let alone one that was successful and won the competition.
With that, we packed up and left the rocket pasture at
18:00. At this point, exhaustion hit us. None of us had eaten anything since
breakfast, and the sun got intense through the afternoon. When we originally
planned this weekend, we expected to launch all our rockets Saturday, camp that
evening, and return home Sunday morning. Not what we expected for the weekend,
but I don’t think you’d find anyone who was discontent with our results.
We returned to Stillwater around 9:00 after a celebratory
dinner at Taco Bell. We were all thrilled with the competition, but it was
nonetheless a very long weekend. It didn’t help that I had three assignments
due the next day, and I didn’t get to bed until 3:00 that morning.
On Monday, I got to talk about the competition briefly in
front our Applied Aero class (Dr. Jacob is the professor) and show a few
videos. Our team has received congratulatory remarks from our friends and the
Mechanical and Aerospace Engineering department head.
Through all of this, I’m still trying to
comprehend that this rocketry program didn’t even exist eight months ago. Even
six months ago, we had no other certified rocketeers, hadn’t flow a rocket with
electronics, and hadn’t gone above 1000 feet. Now, we are sponsored by NASA,
have the attention of the whole college, and won our first-ever competition. I
haven’t done this all on my own by any means, but I do feel that I’ve done a
couple things right to get this team where it is. I can’t wait for what else
we’ll accomplish together. My only “regret” is that I wish this idea had come
to me my freshman year. I’m thirteen months away from graduating OSU, but there
is so much more I want for this program. At the very least, I hope I’ve given
it the foundation it needs to grow for many years to come.Inaugural Argonia Cup Champions 2017 |
Comments
Post a Comment