There's a button on the back of the handle that lights up the orange blade when pressed. The space theme adds additional interest along with the "E" in "SPACE" and the "L" in "LIGHT" connecting, reminiscent of the Star Wars logo.
the sticker on the handle includes a key to morse code, so maybe this sword's not for dukin' it out with your buddies but instead a means of communication...
Translation: LETS FIGHT!!!
Above is what it looks like when the orange blade is removed. The white cap can be unscrewed, allowing you to slide in three AA batteries. Mine no longer works, but I remember when it did work that it only lit up and didn't produce any sound effects.
For anyone wondering where I got the Space Light Sword, I'm afraid I can't be of much help. I was a little kid when I got it so the memory's not really clear, but I think I got it at a circus. I know I also got a light up sword that had a curved (like a scimitar or a pirate sword) yellow blade. I don't recall for sure if it had a space theme, but I don't think it did.