Buster's Cube (Unabridged‪)‬

Despite his genius, Buster Ames never made it as a scientist, and despite his ambition, Philip Benson never made it as a fantastically wealthy entrepreneur. But when an afternoon fooling around with four-dimensional cubes snares the duo a fully working spacecraft, Philip sees the way to untold riches: an interplanetary passenger service. All they have to do is find passengers without alerting the authorities, fly into space without alerting the Air Force, and find their way across the solar system with only a box of sandwiches and a hacked sat-nav.