November Launch in Argonia

The last month has been a busy one for OSU’s AIAA High-Power Rocketry Team!

After our October launch date, we had a collective meeting as an entire team and shifted into a new direction. Our single group split into multiple teams with each team having a focus in the rocket development process. Those teams are Modeling, Assembly, Electronics, and R&D.

Modeling is responsible for designing future rockets using OpenRocket and determining what performance specs we’re looking at for that rocket. Once they’ve come up with the overall design including dimensions and materials, they pass that information along to have those parts ordered.

Once the parts have come in, the Assembly Team takes over and puts the whole thing together for a “scratch-built” rocket. Instead of purchasing fins, we bought ¼” plywood and laser-cut our own custom fins.

The Electronics Team set up our altimeter bay and tested altimeters and weather probes we included in the rocket. Thanks to their efforts, we could use dual-deployment for the first time with this launch.

Our R&D team isn’t as strictly defined because they are responsible for developing the technologies we’ll use in the long term (Argonia Cup and SAC/IREC 2017). They’ll become much more involved in the spring.

Anyway, once we’d split into each team (each team has about 10 members, some of whom are in multiple groups), we could divide the tasks leading up to launching our second rocket. We’d been targeting the November 13^th launch in Tulsa, but the club in Argonia, KS (same place as Airfest), was also holding a launch that same day. We decided to go to Argonia because while the drive is only 15 minutes longer, there is far more space out there and less risk of losing a rocket to a tree. I’d also be attempting my Level 2 Certification with the same rocket, Mach Wave I, that I used for my Level 1. Given how high it would go, I wanted all the space I could get.

Designing and modeling the rocket was straightforward; we’d decided to reuse many parts from other rockets (4” nosecone, 4” airframe, parachutes, shock cord, 4” electronics bay), and it came out to be six and a half feet tall. We ordered the remaining necessary parts and began assembly. Because one of our suppliers didn’t tell us he was out of plywood, the wood to cut our fins didn’t arrive until three days prior to launch which made the last several days quite rushed.

Nonetheless, at 11:00pm the night before launch, we’d managed to finish building the rocket, painting, and integrating the electronics bay. At midnight, I was back home studying for the Level 2 written test, I realized we had no way to arm our electronics from outside the rocket. I reluctantly texted our Electronics Team leader, and fortunately he said he’d just have to do a quick solder in the morning. Sure enough, he got it done before we were even scheduled to leave Stillwater at 8:00 that morning.

Upon arriving in Argonia, we began setting up and prepping everything for launch. I’d have to wait a while for my certification flight because the Tripoli prefect who would administer my test was out flying in his plane.

Mach Wave I and Be Beloved being prepared for flight

Electronics Bay Prep

Finalizing electronics bay assembly

   

Be Beloved on the pad

The club’s rocket, Be Beloved, named after a quote from our fluid mechanics professor, was ready for launch on an I140W. The modeling team projected maximum altitude at 1400 feet, so we programmed the altimeter to deploy the main parachute at 900 feet. Well what the modeling guys forgot was to add the weight of the electronics bay and recovery equipment after they’d initially designed the exterior of the rocket. Be Beloved never made it past 800 feet, but fortunately as a fail-safe, the altimeter deployed both the drogue and main chute at apogee, so our electronics were nonetheless successful.

Recovery without damage

After that launch, I took and aced the written test, and I was all set to prepare for my certification flight. I’d coordinated the week beforehand with a vendor to purchase a J270 DMS motor. Turns out, I didn’t mention that I’d be coming on the second day of the two-day launch weekend, so he’d sold it the day before and didn’t have any others available. I asked around with the other club members, and luckily one gentleman had a J350W reload I bought from him for $60. This worked out really well, because while I was expecting to buy a DMS motor that day, I brought all the reloadable motor hardware with us just in case, and sure enough, I ended up using it for the certification flight.

Finally, I had everything ready for my flight. Over the previous week I’d taken advanced methods to add weight to the nosecone I’d be using to make the rocket more stable. Those “advanced methods” included pouring flour and sand through a plastic cup funnel to add 5 pounds of ballast and fill the rest of the remaining space with expanding foam insulation to keep the sand and flour in place. As I showed my rocket to the Tripoli prefect who would approve my flight was afraid my rocket would “zipper” because I’d added too much weight to the nose. A zipper is a rip in the airframe. When the black powder ejection charge fires, it propels the two pieces of the rocket in opposite directions at high speed to pull out the parachute. With such a heavy nose, the tension that would be created in the shock cord keeping the two pieces of the rocket together could cause the shock cord to rip right through the cardboard airframe. There was no guarantee that would even happen, but I decided to not risk it on a certification flight.

This meant I had to find a similar improvised solution like I did last month in Tulsa when I had to add weight to the nose. This time, I took the nosecone from Be Beloved and with the help of a dozen aerospace engineering students, we tied a baggie full of ratchet wrench sockets to the base of the nose and supported it from below by stuffing tennis balls to fill up the remaining space inside the airframe. This added just enough weight to separate the CG and CP by four inches. On the new software simulation I ran, this rocket would fly to 3200 feet. We got a tracking team downrange to follow the rocket as it would likely drift with the wind.

Mach Wave I flew perfectly and slowing drifted back to Earth on a 48” chute. No one chased after the rocket, so my friend and I booked it in his car all the way down the road, and after walking for five minutes through what was left of a corn field, I found the rocket a little dirty, but without damage. I brought it back to the site to have my paperwork signed, and that is how I became a Level 2 certified flyer!

Finding Mach Wave I a half mile from the launch site

After getting Level 2 paperwork signed!

With that, the day’s launch was a tremendous success! We drove home and returned our materials to the lab.

This week following the launch was full of preparation for our time over the next two months. We’re trying to coordinate as much as possible now before the holidays so that we can still make progress even if we aren’t all in Stillwater. This includes seeking sponsorship from aerospace companies, designing future rockets, and developing a game plan as to effectively use our precious time once we return for the spring semester.

One of the rocket motors we have available for use is an I500T which will burn for less than a second and provide high g forces. My friend and I are sponsoring a contest within our club for someone to design a rocket in OpenRocket that will fly on that one motor alone and reach Mach 2.0. My friend and I made a minimum-diameter rocket out of fiberglass that hit Mach 1.8, so we’ll see if any of our members can beat us. Either way, we intend to purchase the parts and fly it for fun. It should be exciting as our initial model pulled 70 G’s and hit 6500 feet!

Finally, several of us are spending part of the weekend in the lab clearing out many unwanted and unused parts including airplane wings, sheets of composites, and scrap pieces that have accumulated over the years before we inherited the space. It’s wonderful to be dedicating that lab room exclusively for our use and making it our own.

Oklahoma State University's AIAA HPR Team