GLAST has just been successfully launched into low earth orbit. GLAST is a gamma ray space observatory which you can think of as the Hubble for gamma rays. It should be able to observe a very different universe than what we can see with visible light. Stuff such as active galactic nuclei, thirsty black holes, and large exploding stars are among the things that it should be able to observe. And who knows? It might actually give us a clue on what dark matter is.
The photograph of GLAST at the Naval Research Observatory is from the archives of NASA.