In the Vertical Processing Facility, a TRW technician checks the attachment of the solar panel array (out of sight to the right) to the Chandra x-ray Observatory, at left. Formerly called the Advanced x-ray Astrophysics Facility, Chandra comprises three major elements: the spacecraft, the science instrument module (SIM), and the world's most powerful x-ray telescope. Chandra will allow scientists from around the world to see previously invisible black holes and high-temperature gas clouds, giving the observatory the potential to rewrite the books on the structure and evolution of our universe