I read it as “A Spaceship for the King” I remember reading it and the Kelly Freas cover art, but I’ll be darned if I can remember anything about it.
It’s set in Pournelle’s CoDominium future history, and the planet in question has reverted to a “steam, steel, and coal” stage. When it’s re-discovered by the CoDominium, it will essentially be a protectorate due to its technological backwardness...but if it can demonstrate the ability to send someone into orbit, it will be allowed self-rule.
So with technology that hasn’t yet managed to re-invent the airplane, they have to make a spaceship.