At The newly Upgraded KSC funding was tight after the completion of Kerbin Station Alpha, and was barely afloat with shuttle missions and satellite contracts.
Gene Kerman, slightly drunk after the party that ensued after the station was in orbit, and Jeb was back home, Had been contacted by a Jacob Kerman who offered a very lucrative contract which gene signed without reading the fine print.
He Had just accepted a mission to Jool, to land on all 5 of its moons, and return in one ship.
Wernher had an unexpected visit from Gene who asked him to design a vessel for the mission.
After a few frantic weeks, Wernher had come up with a vessel for the trip.
But first...
He wanted to launch a few probes.
https://imgur.com/gallery/mvheXqo