One of the longer-running R&D programs has been work on docking ports for spacecraft to join up in orbit and transfer crew and materiel. The program was begun after orbital rendezvous of spacecraft was proven to be not only possible but capable by astronauts fresh out of the Academy. The ability to join craft via fuel lines is extremely limited for long-term space operations and the eventual construction of a space station. For the first docking, a kerbed craft will rendezvous and couple with an un-kerbed craft launched into orbit ahead of time. This is mainly due to our current small astronaut corps and the unwillingness, at this stage in our program, to have two kerbed flights in orbit at the same time.
