Large rocket test flight worth the wait

11/11/2021

Debra Levey Larson

members of the launch team with rocket
Illinois Space Society members of the Endurance large rocket team 

The Illinois Space Society's large rocketry team recently launched its test rocket. The successful flight, which surpassed its altitude goal, was the culmination of several years of work. The entire project provided unbeatable hands-on experience and a big boost to the morale of the more than 70 students who worked on it.

Although the rocket was named Endurance, inspired by the spaceship in the film “Interstellar,” the team members demonstrated tremendous endurance in just getting it to the launch pad. The rocket was developed based on the designs that the team created for the Spaceport America Cup 2021 competition which went virtual due to the pandemic.

The team had several technical goals, including to test their avionics bay, the active control system with its actuating flaps, the tender descender method of parachute deployment, and the structure. But the timing of scheduling the launch early in the semester was also important.

test flight of Endurance
Test flight of Endurance

“We wanted to give freshmen and other new members the experience of launching a rocket within the first couple of months of the academic year,” said Anshuk Chigullapalli, Illinois Space Society’s technical director, and currently an aerospace engineering junior at the University of I

llinois Urbana-Champaign. “ISS members have stayed dedicated to the large rocketry project throughout COVID and the online semesters. Now that we’re back in-person, we finally got the opportunity to train new members and get the launch experience we were all waiting for.”

Chigullapalli said the rocket was very stable and hit the desired apogee. As this was just a test flight, the goal was to reach 9,200 feet in altitude. Endurance topped out at 9,327 feet. The rocket was recovered safely with all its parts intact, including the sensitive avionics.

A view from the on-board camera. Watch the video it recorded on the Aerospace Engineering YouTube channel.
A view from the on-board camera. Watch the video it recorded on the Aerospace Engineering YouTube channel

“We put a camera on the side of the rocket and got some incredible footage. You can see the flaps pop out and move as the roll rate changes,” Chigullapalli said. “But what was most amazing is that this was the first time two years that we’ve been able to successfully deploy an active control system. It controlled the flaps to modify the roll torque on the rocket autonomously during flight.

“One of the main things the team learned that implementing a controller is a whole different ballgame than just designing one. A lot of the team members have already taken AE 353 – Aerospace Control Systems. In that class, we learn to design feedback controllers that optimally control a system. However, to implement a controller you need to work with sensors, with on-board software,

derive the dynamics yourself and build the actuator system. Even then, things in real life never match simulation. The team got an incredible amount of hands-on experience and the result is clear in the video,” Chigullapalli said.

He added that the controls aspect is only a small part of the whole team involved in the project.

Preparing for the launch
Preparing to launch

Just as building the control system gave crucial hands-on experience, everyone involved learned valuable skills from the aspect they worked on, whether it was handling parachutes, using tools to make modifications to the rocket body, making CAD parts and engineering drawings for the AE machine shop to manufacture new fins,

learning to wire different components and fasten everything securely, calculating the dynamics of the rocket, assembling and painting the rocket, and more.

The primary leads were: Ayberk Yaraneri (senior in aerospace) – large rocketry tech manager and team lead; Ben Olaivar (sophomore in computer engineering) – avionics lead; Sebastian Macias (junior in aerospace) – structures lead; and Luke Leddy (sopho

more in industrial engineering) – safety and logistics officer.

Endurance's avionics bay
Endurance's avionics bay

Some additional details about the rocket:

•             The rocket structure is made of fiberglass, including the nose cone and the fins. The fins were designed by the team to make the rocket stable even in heavy winds.

•             The team built the avionics bay from the ground up, including the circuit boards, the wire harnessing, all the software, the servomotors and the control algorithms.

•             The rocket motor was a commercial, off-the-shelf M6000 motor.

Illinois Space Society is the University of Illinois chapter of Students for the Exploration and Development of Space and has over 140 active members.

Professor Zachary Putnam is the faculty adviser for ISS. Aerospace Professors Tim Bretl and Melkior Ornik provided guidance and feedback to the Endurance team. Mark Joseph and Jonathan Sivier, who are both associated with Central Illinois Aerospace, also served as rocket advisers.