The Space Core is the yellow eyed core, who occasionally lets off sparks as it twitches, from Portal 2. Space Core was the result of the writers wanting a "rainman personality core" that wanted, and focused, only on one thing. Initially the writers didn't know what his one interest should be, but after deciding how the game would end, the answer was 'space'.
It is said by the writers themselves that Core 1 was the only character in the game to have a truly happy ending, although this is clearly inaccurate as Chell is reunited with the Weighted Companion Cube and set free. His dialogue is characterized by fast excited statements and exclamations. His design is based on the personality cores seen at the end of Portal.
At the end of Portal 2, when it is floating in space with Wheatley, it repeats "So much space! We're in space!" He does not however seem to know much about space, despite being obsessed with it.
