SOFIA, the Stratospheric Observatory For Infrared Astronomy is an ambitious project. This is an infrared telescope mounted in a modified Boeing 747 airplane. It has been under construction for several years and cost nearly $600 million, but it is finally about finished.
Infrared light, or what most of us would call "heat," allows astronomers to look through clouds of dust in our galaxy, exploring star birth that has been invisible. Infrared light also allows astronomers to look for evidence of planets around other stars. The problem is that most infrared light from space does not reach Earth's surface. So in order to see infrared objects, astronomers need to get above much of the atmosphere. That can be done with satellites, like the Spitzer Space Telescope, or with airplanes.
So, after a lot of time and money, SOFIA is just about ready to fly. So why has NASA zeroed out the budget starting in 2007? Without (promised) money, SOFIA will not be able to operate, and $600 million of equipment, not to mention a world-class telescope, will sit in storage, doing nobody any good. Yes, SOFIA has had problems and cost overruns. And yes, money is tight. But it seems wasteful not to try.
SOFIA is not dead yet; it will have a performance review soon and could easily see its funding restored. Let's hope all goes well!