Back near the end of 2025, December 22, South Korean rocket company Innospace sent its Hanbit-Nano rocket skyward for the first time ever, from the Alcantara Space Center in Brazil. But the landmark flight — the first-ever orbital launch attempt by a South Korean company — didn't last long, as the Hanbit-Nano exploded less than a minute after leaving the pad.
Now Innospace has released new details about that launch failure and the results from a joint investigation, which shed light on what went wrong and how the company plans to move forward.
A gas leak in the forward section of Hanbit-Nano's first-stage hybrid rocket combustion chamber triggered a rupture, ultimately leading to mission failure, according to a March 17 Innospace update.
The leak "was caused by insufficient compression and uneven sealing performance resulting from plastic deformation of sealing components during the reassembly process following the replacement of the forward chamber plug during launch preparation activities in Brazil," the update reads.
Talking about "plastic deformation of sealing components" sounds a lot like the kind of improper sealing that gets seen pretty regularly on SLS and other launch vehicles.
The Hanbit-Nano first stage uses a fuel combination I don't recall hearing about before, Liquid Oxygen is the oxidizer and the common part, while the fuel itself is paraffin. There are two versions of the second stage, which will run on either the same paraffin/LOX combination as the booster or with a liquid methane/LOX. Hanbit-Nano is a small, 57-foot-tall, light-lift system designed to put 90 kg (about 198 lb.s) into a sun-synchronous orbit from its Brazilian launch pad. For comparison, the Rocket Lab Electron is a small payload launcher as well but it's rated for 660 pounds to LEO, over 3x the Hanbit-Nano's payload.
Innospace conducted its investigation into the mission's failure alongside CENIPA, the Brazilian Air Force authority responsible for aerospace accident investigations. Innospace says it is already implementing design improvements to affected components and introducing additional verification steps to prevent similar failures in future launches.
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The company plans to move ahead with a follow-up launch, pending authorization from the Korea Aerospace Administration (KASA). That next attempt is currently targeted for the third quarter of 2026, with Brazil expected to remain the launch site.
The South Korean rocket company Innospace has closed its investigation into
the failure of its Hanbit-Nano rocket in December and is targeting the third
quarter of 2026 for its next launch. (Image credit: Innospace)
Paraffin is not a structurally strong material at even room temperature let alone Brazilian summer. Are they using as a solid or a heated liquid? As well it has a higher carbon to hydrogen ratio than methane or kerosene. Must be the oriental mind at work. Will be interesting to learn how their follow-up performs.
ReplyDeleteSolid paraffin though your point about melting might have bearing on the failure?
DeleteSome people refer to kerosene as paraffin, so they may mean kerosene - which makes lots more sense than the wax we in the US usually refer to paraffin.
ReplyDeleteJonathan
Innospace says the paraffin is "solid". They chose it over other solids because it was less likely to spontaneously explode. The link discusses the fuel in the prior test vehicle; I was not able to confirm the composition of the paraffin is the same in the two rockets. https://www.innospc.com/myboard/sub04_02/178285
DeleteHybrid rockets are a mix of solid and liquid or gas. Hence the parafin, which provides the fuel while LOx or LO2 would be the throttleable oxidizer.
DeleteSo what does that look like? Is the top of the combustion chamber a solid block of paraffin and they just sprinkle LOX onto it with a continuous burn, or - I don't know - a cheese grater to make powdered paraffin that gets trickled or dumped into a combustion chamber? It can't it be like a solid fueled rocket with the oxidizer and fuel cast into a single block - like SRBs we see everywhere. If it was that, they couldn't use liquid oxygen.
DeleteIt's Wikipedia, but this is not political nor religious, so it tends to be accurate:https://en.wikipedia.org/wiki/Hybrid-propellant_rocket
DeleteThanks, Mark. The Wikipedia link helps. For some reason the "Basic Concepts" section's illustration resonated a lot better in my mind than the leading section's.
DeleteThanks also to "Old Surfer" as well.
The fuel grain looks much like a solid fuel grain, the whole tube forms the combustion chamber, oxygen fed in at the top.
ReplyDelete