The European Space Agency is getting ready to loft the biggest mirror ever in a space telescope: the 3.5 meter giant for the Herschel Space Telescope. That's big: Hubble's is only 2.4 meters, so this one will have over twice the area of Hubble.
Incredibly, the whole mirror assembly -- the big primary, a smaller secondary, and the support structure -- will mass only 320 kilograms (700 pounds). That's incredibly lightweight for such a large amount of hardware! I'm impressed.
The picture above shows this cool device (click here for a very embiggened picture). The telescope is optimized for far infrared light; meaning it will look at dusty disks around stars, planets and stars forming, ancient distant galaxies, and more. No space telescope has ever looked at just these wavelengths before, so this should provide an interesting view of the Universe. It's supposed to launch late this year. I can't wait!