College kids at the University of Southern California (USC) blasted above an international altitude record, launching an amateur rocket 470,000 feet into space.
The spacecraft, Aftershock II, has now bested a 20-year-old record held by hobbyists with the Civilian Space eXploration Team (CSXT), who managed to launch their rocket 380,000-feet high in 2004.
But USC’s Aftershock II also reached hypersonic speeds — reaching a maximum velocity of 5,283 feet-per-second at Mach 5.5, or over five times the speed of sound.
Now their intentionally lightweight rocket, which comes in at about 330 pounds, has made history as the first launch by individuals outside of government or private industry to ever ascend this far beyond Earth’s atmosphere.
Undergraduate student Ryan Kraemer,, who worked as an executive engineer on the project, said Aftershock II boasted ‘the most powerful solid-propellant motor ever fired by students and the most powerful composite case motor made by amateurs.’
The 13-ft tall, eight-inch diameter craft was fueled by a custom-made, ‘ammonium perchlorate composite’ solid chemical propellant, invented by students themselves.
‘Using a formula developed by students in the club,’ according to the USC Rocket Propulsion Lab (USCRPL), ‘each propellant grain is made by USCRPL starting from raw chemicals, setting the club apart from many other collegiate rocketry teams.’
Fittingly, USC’s Aftershock II and CSXT’s prior record-holder were both launched from the same spot: the remote Black Rock Desert, 100 miles north of Reno, Nevada.
The University of Southern California’s student-led Rocket Propulsion Lab (USCRPL) designed and built the new record-setting rocket, Aftershock II. Above, the nose cone of the student rocket, photographed in space amid their successful, historic October 20, 2024 space launch
The student rocket bested a 20-year record held by hobbyists with the Civilian Space eXploration Team (CSXT) – who launched a rocket 380,000-feet high in 2004, passed the official boundary into space. Above, video from inside the USC rocket that beat CSXT’s record
USCRPL students last made history in 2019, when the club became the first student group to fire a rocket above the Kármán line: the internationally recognized legal boundary dividing Earth’s atmosphere from outer space, 62 miles above sea level.
Aftershock II climbed a further 27 miles into space, for a total of 89 miles.
‘This extraordinary group of students shows how to imagine, what can be done in the lab, and how to make it a reality.’ Yannis Yortsos, dean of the USC’s Los Angeles-based Viterbi School of Engineering, said in a university statement.
‘It is thrilling to see how they have now shattered not only their previous global student record of reaching the Kármán line,’ Yortsos added, ‘but also the record of any amateur team in history.’
The rocket’s ability to endure the heat and friction of its Mach 5.5 hypersonic ascent was made possible the club’s new thermal protection design — which included a new paint job and titanium-coating for the rocket’s fins.
‘The titanium not only prevented fraying but actually turned blue from the intense heat during flight through anodization,’ according to Kraemer, who is majoring in mechanical engineering when not active with USCRPL.
The hot anodizing reaction with the oxygen gas rubbing against these fins, he said, ‘really demonstrates the extreme conditions our rocket successfully endured.’
‘Thermal protection at hypersonic speeds is a major challenge at the industry level,’ the student added, ‘and the protective paint system that we developed performed perfectly, enabling the rocket to return largely intact.
Fittingly, USC’s Aftershock II and CSXT’s prior record-holder were both launched from the arid and remote Black Rock Desert, 100 miles north of Reno, Nevada. Above, students with the USC Rocket Propulsion Laboratory club watch as their Aftershock II blasts off on October 20, 2024
Dubbed the ‘High Altitude Module for Sensing, Telemetry, and Electronic Recovery’ or ‘HAMSTER’ system (above), USCRPL’s custom avionics suite included a radio-based transponder to measure altitude and five printed circuit boards’ worth of computational might
Prior versions of the USCRPL’s rocket fins had edges composed of bare carbon.
The club’s last history making rocket, Traveler IV launched in 2019, had returned from beyond the Kármán line with the paint on the rocket ‘completely burned off’ and ‘excessive’ heating damage ‘on the fin’s leading edges.’
‘To exceed the standard we set for ourselves with Traveler IV, we had to solve many technical and operational challenges,’ Kraemer noted.
To power its surge beyond Earth’s atmosphere, for example, Aftershock II’s solid fuel motor ultimately required nearly 200 pounds of propellant comprised mainly of controlled-release propellant grains, known in the industry as BATES-type.
The team also had to design and program a unique avionics system, both to guide the craft and record flight data that would be used in their official paper on the historic Aftershock II launch, published on November 14.
Dubbed the ‘High Altitude Module for Sensing, Telemetry, and Electronic Recovery’ or ‘HAMSTER’ system, USCRPL’s custom avionics suite included a radio-based transponder to measure altitude and five printed circuit boards’ worth of computational might.
HAMSTER’s Integrator Board integrated together sensor live sensor data from the rocket’s magnetometer, gyroscope, and accelerometer to pin-point the rocket’s highest point, or apogee.
And its ‘Lightspeed Rangefinder Transponder’ measured its distance to multiple points on the ground to calculate the craft’s radio-based, radar-like method known as trilateration.