Centennial

Centennial is a 4-inch dual-stage rocket designed for the 2024 Argonia Cup based in Argonia, Kansas. Competing teams were tasked with designing and launching a dual-stage rocket that could carry as many golf balls as high as possible. All competing rockets were constrained to a total impulse limit of 5200 Ns.

Standing over 11 feet and weighing 34.5 lbs, Centennial is designed to reach an apogee of 12,500 feet while carrying 81 golf balls to score about 113,000 points in the competition. The vehicle is powered by two motors: the Aerotech K1999 in the booster section and the Aerotech K250 in the sustainer.

On March 23rd, 2024, Centennial was successfully launched to 10,243ft at the 2024 Argonia Cup, carrying 81 golf balls.  

Structure

Illinois Tech Rocketry hosted an IPRO class for the Argonia Team during the spring semester. Throughout the semester, our IPRO students had a chance to visit Illinois Tech's Student Machine Shop to gain hands-on experience. At the Machine Shop, the students cut fiberglass tubes for the avionics bay coupler and airframe using a band saw and threaded aluminum rods for Centennial’s payload using a CNC lathe.

Our student also got to learn using CAD software like SolidWorks as well as CAM like Rhino to export file for CNC router.

Avionics

Centennial’s avionics are separated into two different AV bays: one in the sustainer and one in the booster. The booster AV bay is in charge of stage separation and apogee deployment of the booster’s parachute, while the sustainer AV bay is in charge of sustainer ignition, apogee, and main chute deployment. Both AV bays feature a fully dual redundant system incorporating Altus Metrum’s TeleMega and Featherweight Altimeters’ Blue Raven flight computers. To ensure full redundancy, both flight computers use separate batteries and pull pin switches, with the Telemega’s using an extra battery for pyro charges to provide a stable voltage. For the Telemega, pull-pin switches are used to turn on the main battery, pyro battery, and motor ignition to ensure safety. The Blue Raven has a single pull-pin for power but features wifi arming and disarming for pyro charges.

The AV bays are designed to fit within a 10-inch coupler that joins the upper and lower airframe sections and is held in place by a 2-inch switch-band for the pull-pin switches. The flight computers are housed on two 3.5-inch by 9.8-inch rectangular sleds, with eight spacers placed along the edges to ensure structural integrity. The sleds are 3D printed out of PLA and designed to perfectly house all of our electronics, with holes integrated into the print to ensure electronics boards are correctly oriented. 

The bulkheads of the AV bay are manufactured from ¼-inch aluminum 6061 plates. Variants such as 7075 were considered, but we opted for 6061 due to 7075’s poor corrosive performance. The bulkheads were designed in SolidWorks and machined using a CNC router to ensure all holes were perfectly positioned and the stepped portion of the bulkhead was entirely flat. 

Shock cords attach to each end of the AV bay via a 3/16-inch zinc-plated steel eye bolt rated for 600 lb. Connecting the AV Bay sled to the bulkheads are 3/16-inch chromate-plated steel threaded rods. These rods are secured to the sled through the sled spacers and fastened with epoxy and an anchoring nut. The bulkhead then connects to the rods through lock washers and nuts. All hardware in the AV bays was selected to ensure corrosion resistance and avoid degradation from black powder charges.

Gallery

2024 Argonia Cup