Space Shuttle Endeavour thunders off into orbit in a rare night launch. This March 1995 mission is most famous for operating the set of astronomical telescopes known as Astro-2. Astro-2's telescopes observed the universe in ultraviolet light - light so blue humans by themselves can't see it. Astro-2 measured the amount of ultraviolet light emitted by several interesting stars, galaxies, planets, and QSOs. Analysis of data from this NASA mission has yielded the first clear detection of helium created during the beginning of the universe.