The Bad-ass gravity pump was an invention created by Professor Farnsworth and Ethan "Bubblegum" Tate. The main purpose of the invention was to move stars. The giant basketball on the end is to represent the fact that Bubblegum is a professional Basketball player. It was attached to the Planet Express ship and Fry controlled it to spell out the message "I Love You, Leela" with the stars before they were destroyed.