University Students Launch Successful Re-Entry Experiment with KREPE-2 Capsules

In a remarkable demonstration of courage and ingenuity, university students have successfully launched experimental capsules designed to withstand the extremes of re-entry into Earth’s atmosphere. This ambitious endeavor, known as the Kentucky Re-Entry Probe Experiment (KREPE-2), marks a significant milestone in advancing spacecraft heat shield technology, a critical component for safe space travel. By pushing the boundaries of knowledge through hands-on experimentation, these students have illuminated the path for future innovations in aerospace engineering.

The KREPE-2 mission, initiated in July 2024, involved the construction and testing of five football-sized capsules, all meticulously crafted by students at the University of Kentucky. Funded by NASA’s Established Program to Stimulate Competitive Research (EPSCoR), these capsules were engineered to endure the caustic conditions of re-entry, with temperatures soaring above 4,000 degrees Fahrenheit. The data collected during this fiery descent will provide invaluable insights for refining heat shield designs used in both crewed and uncrewed missions.

Stan Bouslog, a thermal protection system expert at NASA’s Johnson Space Center, emphasized the significance of this hands-on approach. “The only way to ‘test like you fly’ a thermal protection system is to expose it to actual hypersonic flight through an atmosphere,” he stated. This assertion showcases the necessity of real-world testing, where simulations cannot fully replicate the complexities of re-entry.

The capsules were launched aboard an uncrewed Northrop Grumman Cygnus spacecraft in January 2024. After successfully detaching from the International Space Station on July 12, the Cygnus initiated its planned re-entry over the south Atlantic Ocean. As the spacecraft began to disintegrate, the KREPE-2 capsules were released at an incredible speed of approximately 16,000 miles per hour from an altitude of around 180,000 feet. The capsules were able to transmit crucial data back to Earth via the Iridium satellite network, marking a successful mission milestone.

  • The sensors onboard detected key metrics, such as temperature fluctuations and changes in acceleration, essential for understanding the dynamics of re-entry.
  • A team, led by Alexandre Martin, a professor of mechanical and aerospace engineering at the University of Kentucky, coordinated closely with international partners to observe and analyze the re-entry event.
  • Cameras and spectrometers were deployed to capture real-time scientific measurements, enhancing the team’s understanding of the break-up dynamics of the Cygnus vehicle.

“We now have a much better understanding of the break-up event of the Cygnus vehicle, and thus the release of the capsules,” Professor Martin elaborated. His comments reflect the collaborative spirit of the mission, which involved researchers from the University of Southern Queensland in Australia and the University of Stuttgart in Germany.

Back at the University of Kentucky’s Hypersonic Institute, the anticipation was palpable as team members awaited updates during the capsules’ descent. The efficient transmission of data confirmed a significant achievement: all five capsules successfully relayed information back to mission control.

Martin noted the importance of this process, stating, “It will take time to extract the data and analyze it. But the big accomplishment was that every capsule sent data.” This effort not only demonstrates the resilience of the capsules but also showcases the students’ dedication to the field of aerospace engineering.

The data collected from KREPE-2 far surpasses that of the initial KREPE-1 mission, which launched two capsules in December 2022. While KREPE-1 primarily focused on demonstrating the feasibility of data collection during re-entry, KREPE-2 expanded the scope by capturing a broader suite of metrics, including:

  • Heat shield temperatures
  • Pressure readings
  • Acceleration data
  • Angular velocity measurements
  • Spectral data on the shockwave preceding the capsules

“KREPE-1 was really to show we could do it,” Martin remarked, underscoring the evolution of the project. “For KREPE-2, we wanted to fully instrument the capsules and really see what we could learn.”

The momentum generated by KREPE-2 paves the way for future endeavors, with plans for KREPE-3 set for 2026. This iterative process enables students at various educational levels—ranging from undergraduates to PhD candidates—to gain invaluable hands-on experience in developing spaceflight technology. The project not only fosters a learning environment but also empowers students to take ownership of their creations and innovations.

Martin further highlighted the importance of student agency within this project: “This effort is done by students entirely: fabrication, running simulations, handling all the NASA reviews, and doing all the testing. We’re there supervising, of course, but it’s always the students who make these missions possible.”

This collaborative venture between academia and space agencies exemplifies the profound impact of educational programs in the realms of science and technology. The courage and determination displayed by these university students resonate through their innovative efforts, inspiring the next generation of explorers who will one day journey beyond our atmosphere.