South Korea lost contact with their launch vehicle a little over two minutes into its flight profile and during its first stage burn.
It was to hoist a modest 100kg payload and the launch vehicle itself was similarly modest–we’ll call it old school–with a Russian supplied first stage that used the traditional ‘highly refined hydrocarbon (kerosene) and liquid oxygen as fuel. The second stage was a solid. This is the second consecutive failure.
South Korea, as does SpaceX, knows the challenge of building a space launch vehicle and getting to space. If it was easy, many more would already have done it.
SpaceX achieved success with its Falcon 1 on its fourth attempt and was fully successful on their first attempt with the much more capable Falcon 9 vehicle.
Expect South Korea to be tenacious as well.