The 3.5-meter-long SST3 soared to an altitude of 8.3 kilometers, becoming the largest solid-propellant sounding rocket launched in Taiwan to date by a university-led team. (Photo credit: TASA)

SST3 Reaches 8.3 Kilometers and Sets a New Benchmark

The SST3 stood 3.5 meters tall and measured 16.3 centimeters in diameter. Its target was ambitious: 9 kilometers, roughly three times the altitude pursued in the team’s earlier test program. The rocket was developed to validate the performance and system specifications needed to compete in the 30,000-foot category of the Intercollegiate Rocket Engineering Competition (IREC) in the United States.

Earlier rockets in the SST series focused on flights in the 3-kilometer range. Reaching for 9 kilometers meant the team needed more thrust, longer burn time and stronger protection against heat and structural stress. At the heart of the upgraded rocket was the Pioneer-50K RNX, a solid-propellant propulsion system developed under the leadership of the Advanced Rocket Research Center (ARRC) at NYCU.

Although SST3 fell short of its 9-kilometer target, the flight represented a dramatic leap from the team’s earlier 3-kilometer tests and set a new record for a solid-rocket launch led by Taiwan’s academic community and conducted in the country. The rocket also successfully transmitted critical flight data to the ground. The flight data gave the team a detailed record of the rocket’s performance and will serve as a foundation for improving the recovery system ahead of future launches and international competitions.

For the students behind the rocket, the successful liftoff followed months of testing and redesign. “To withstand higher temperatures and sustain thrust for a longer period, we had to set much stricter thermal-protection requirements,” said Dan-Ying Cao, a first-year doctoral student in NYCU’s Department of Mechanical Engineering. “That meant conducting many more tests. Seeing the rocket lift off successfully made all that work worthwhile.”

The higher total impulse also placed greater stress on the rocket’s fins. “The structural strength of the fins became a major challenge,” said Yung-Ching Cheng, a second-year master’s student. “It was one of the areas where the team invested the most time and effort.”

One was built to fly higher than any comparable solid rocket launched by Taiwan’s academic community. It reached 8.3 kilometers. The other climbed only 532 meters. But altitude told just part of its story: It became the first rocket launched in Taiwan using a liquid-propellant system.

 

Both rockets were led by NYCU’s Institute of Space Systems Engineering (iSSE) and ARRC. Faculty members and students worked across every stage of development, from initial design and manufacturing to testing, systems integration and launch operations.

FARCX-1 Takes a Crucial Step toward Liquid Propulsion

The FARCX-1 measures 16.3 centimeters in diameter and 4 meters in length. Its primary mission was to validate the propulsion technology, rocket-system specifications and integration capabilities required for IREC’s Student Researched and Developed (SRAD) category. Unlike most student rockets, which use solid propellants, the FARCX-1 is equipped with a liquid-propellant system developed under the leadership of ARRC. The system uses high-concentration hydrogen peroxide as its oxidizer and kerosene as its fuel.

Liquid-propellant rockets require systems for fuel delivery, ignition, combustion control and multiple layers of safety protection. Their complexity and integration requirements are considerably greater than those of solid-propellant rockets. The FARCX-1 successfully lifted off, reached an altitude of 532 meters and transmitted critical flight data.

The launch achieved Taiwan’s first flight of a rocket powered by a liquid-propellant system. More than the completion of a single rocket, the achievement represents an important step for Taiwanese students and academic researchers developing liquid-propulsion technology independently. The results will provide a foundation for increasing thrust and flight altitude while improving system reliability in future missions.

Kao-San Lin, a fourth-year student in NYCU’s Department of Mechanical Engineering and a member of the FARCX-1 team, said building the liquid engine required the team to make the internal piping as compact as possible while carefully determining the location of each valve. “Every modification had to be followed by another ground test,” Lin said. “Altogether, we conducted five or six rounds of ground testing.”

Assistant Professor Shih-Sin Wei, who teaches NYCU’s Space Systems Integration course, said completing two rockets with different propulsion systems within a single semester was an enormous undertaking.

The 4.1-meter-long FARCX-1 reached an altitude of 532 meters, becoming Taiwan’s first student-developed liquid-propellant sounding rocket to successfully complete a flight test.

Building Experience for Future Competitions

As the Taiwan Cup Rocket Competition grows and its launch missions become increasingly complex, teams must do more than solve engineering and manufacturing problems. They must also use systems-engineering methods to coordinate technologies and resources across universities, academic disciplines and student teams — while, in this case, carrying out two fundamentally different launch missions at the same time.

NYCU hopes the technical demonstrations and results from the two launches will help teams competing in future Taiwan Cup and international rocket competitions build greater expertise in rocket design, propulsion, flight control and systems integration. The project is also expected to advance academic research on rockets in Taiwan and support the development of the country’s next generation of space-engineering professionals.