UPDATE: As of mid-July, 2014, parts of this mural look different and include more Star Wars stuff. As of August 9, 2015, no traces of the original were visible and it was actively being repainted, particular the part that formerly showed the death star. Pictures of the mural can be seen here.
The Simpsons in Space Mural (actual title unknown) was on the back of the building that houses Hawker Fare at 320 23rd St. It includes a number of stylized tags, and features characters from The Simpsons TV show, with Homer in Star Wars stormtrooper armor. There's also an image of The Great Gazoo who appeared in The Flintstones TV show and was obliquely referenced in The Simpsons as Ozmodiar. A side panel includes an image of the Star Wars Death Star and a TIE fighter.
Artists are EMT, Goser, MR. EF, Roar, 7Seas, Ryno, Germs, Resk and others. EMT is also responsible for the Tony the Tiger mural nearby.