I think that is certainly possible. Scaring people is what he does best. However, if he really does it to Space Shuttle, this will be probably his last stunt.
He is doing this, most of all, to shore up his domestic base, yes, and keep the bombers and snipers at a safe enough distance from himself, considering how weak his power hold is becoming. Can you believe the DPRK TV news today? I don't know if you saw a clip. Hilarious. The announcer needed to have an assistant wipe up his drool, he was so excited to announced The Republic's launch of these missiles for self defense, and also issue a threat of war while he was at it. Prime Time Pyongyang TV at its best.