ampoule

North Korea said the Wednesday test verified the "reliability of fuel ampoule system under the winter weather conditions", suggesting it is seeking to ensure the stability of such systems.

Recent tests suggest North Korean military scientists are pursuing a third option: a "missile fuel ampoule" system to seal the liquid propellant and oxidizer tanks within the missile's airframe, allowing them to be fuelled at the factory and ready to use.

The same type of rocket booster with an ampoule system may have been used last week in a second hypersonic test.

Pak Jong Chon, a senior official who observed the test, said the North plans to expand the ampoule system to all of its liquid-fuel missiles.

The agency also said the test confirmed the stability of the missile’s “fuel ampoule,” indicating a technology to pre-fuel the liquid propellant missile and seal it in a canister so that it could stay launch-ready for years.