READY: 1 to 3 years The KN-14, which could reach California, has been shown in parades but not flight-tested. David Wright, missile expert at the Union of Concerned Scientists, says that the paraded KN-14 can be seen to have two stages. This indicates that liquid fuel rather than solid is being used. Although liquid fuel requires relatively heavy pumping systems, it tends to be better at lifting mass. And, with fewer stages, there is less potential for complications.