Private South Korean rocket exploded last December due to hardware failure, investigation finds

South Korea's Innospace has closed the books on its first orbital launch failure, and the answer is not a good look for the company's ground operations. The Seoul-based startup announced March 17 that a joint investigation with Brazil's aerospace accident authority CENIPA had pinpointed the cause of the Hanbit-Nano rocket's in-flight breakup on December 22, 2025: a gas leak at the forward section of the first-stage hybrid rocket combustion chamber, 33 seconds after liftoff from the Alcântara Space Center. The leak triggered a rupture that broke the vehicle apart. The root cause was decidedly unglamorous. During launch preparations at Alcântara, technicians had replaced the forward chamber plug — a component sealing the combustion chamber — and then reassembled it. The sealing components suffered plastic deformation during this reassembly, resulting in insufficient compression and uneven sealing. When the rocket lit up and started pushing propellant through that seal, hot combustion gas escaped rather than going out the nozzle. Innospace recovered more than 300 pieces of debris across two phases at the launch site. The flight data, telemetry, tracking records, ground facility data, launch operation logs, and video footage all painted the same picture: nominal liftoff, nominal initial flight, then a fast-developing rupture. Colonel Alexander Coelho Simão, the investigator-in-charge at CENIPA, said the agency maintained close cooperation and transparency with Innospace and Korea's Aerospace Administration throughout the process. CENIPA formally classified the event as an 'incident' rather than an 'accident' — a distinction that matters for regulatory and liability purposes. CEO Soojong Kim called the investigation valuable, saying it had given the company a comprehensive understanding of the launch sequence and technical assets that would inform future improvements. Innospace says it is implementing design upgrades to the affected components, strengthening its assembly and quality management processes, and adding functional verification steps. The company is targeting a follow-up launch in the third quarter of 2026, again from Alcântara, pending authorization from KASA. Hanbit-Nano is a 17.3-meter, two-stage hybrid rocket that burns liquid oxygen and paraffin. Its first commercial mission carried five customer payloads from Brazil and India, plus three technology demonstrators — all lost. The rocket was designed to deliver up to 90 kilograms to sun-synchronous orbit. A first launch failure is not unusual for a new rocket. What matters now is whether Innospace's fixes hold and whether it can demonstrate the reliability that commercial small sat operators need. That Q3 2026 flight will be the real test.