A group of students from the University of Southern California launched the Aftershock II rocket, reaching an altitude of 143.3 meters above the Earth’s surface, breaking multiple records previously held by amateur teams.
The Aftershock II rocket, standing 4 meters tall and weighing 150 kilograms, was launched from the Black Rock Desert in Nevada on October 20. This rocket was designed and built by a student group from the Rocket Propulsion Laboratory (RPL) at USC. RPL is entirely operated by undergraduate students.
Just 2 seconds after launch, Aftershock II broke the sound barrier and reached a maximum speed of approximately 5,800 km/h (Mach 5.5) after 19 seconds. The engine then shut down, but the rocket continued to ascend due to the decreasing atmospheric drag. Aftershock II exited the Earth’s atmosphere after 85 seconds and reached its peak altitude of 143,300 meters after the next 92 seconds.
Aftershock II reaches a maximum altitude of 470,000 feet (143,300 m) above the Earth’s surface, higher than any other amateur rocket. (Photo: USC Viterbi School of Engineering).
This altitude far exceeds the previous record of 115,800 meters set by the GoFast rocket from the Chinese Civil Space Exploration Team in 2004. A USC representative stated this is the “farthest into space that any non-governmental and non-commercial group has ever achieved.”
Ryan Kraemer, a mechanical engineering student at USC and the operational engineer for the RPL team, who will soon join SpaceX’s Starship team, said: “This achievement represents several pioneering engineering advancements. Aftershock II features the strongest solid fuel engine ever made by students and is the most powerful composite shell engine built by amateurs.”
The rocket also reached a maximum speed of 5,800 km/h (Mach 5.5), slightly faster than GoFast’s 20-year-old record. Aftershock II broke not only altitude and speed records.
To achieve this milestone, the Aftershock II team applied new advancements in thermal protection technology, a crucial factor when rockets travel at supersonic speeds (above Mach 5). They coated Aftershock II with a new heat-resistant paint and equipped it with titanium heat shields instead of the carbon materials used in previous models.
Kraemer noted: “Thermal protection at supersonic speeds is a significant challenge at the industry level. The upgrades the team implemented worked perfectly, allowing the rocket to return almost intact.” However, the intense thermal effects caused the titanium fins to change from silver to blue due to a process known as “anodization,” where the metal reacts with oxygen in the atmosphere to create a titanium oxide layer.
The team also designed a new controller for the sensor, distance measurement, and recovery electronics (HASMTER) to monitor the flight and deploy the rocket’s parachute.
In 2019, another student group from RPL became the first student team to launch a rocket beyond the Kármán line, the boundary between Earth and space. Aftershock II is the second student rocket to achieve this milestone.
Dr. Dan Erwin, an aerospace engineer and chair of USC’s Department of Aerospace Engineering, stated: “This is an extremely ambitious project not only for a student group but for any non-professional rocket engineering team. It demonstrates the excellence we seek to develop in our future aerospace engineers.”
