Talk about getting mileage out of a promotion.Lucasfilm is sending the original Luke Skywalker light saber into space, as part of its ongoing 30th-anni celebration of “Star Wars.” Following on the heels of “Star Wars” stamps and R2-D2 mailboxes, the prop wielded by Mark Hamill in the 1977 pic got a sendoff worthy of a visiting dignitary last week. Furry first mate Chewbacca made the handoff to NASA at Oakland Intl. Airport, and a squad of Storm troopers greeted its arrival at Houston’s Hobby Airport on Aug. 28. Next up: an October launch aboard the space shuttle Discovery. And, yes, the light saber will be brought back to Earth.