  The International X-ray Observatory (IXO) is a joint ESA-JAXA-NASA effort to
address fundamental and timely questions in astrophysics: What happens close to
a black hole? How did supermassive black holes grow? How does large scale
structure form? What is the connection between these processes? To address
these questions IXO will employ optics with 3 sq m collecting area and 5 arc
sec angular resolution - 20 times more collecting area at 1 keV than any
previous X-ray observatory. Focal plane instruments will deliver a 100-fold
increase in effective area for high-resolution spectroscopy, deep spectral
imaging over a wide field of view, unprecedented polarimetric sensitivity,
microsecond spectroscopic timing, and high count rate capability. The mission
is being planned for launch in 2021 to an L2 orbit, with a five-year lifetime
and consumables for 10 years.
