via New Scientist.
No-one now complains about images coming back from the Hubble Space Telescope (except for astronomers who failed to get time on it). However, when the space observatory first went up, a problem with the shape of its mirror meant the images that came back were well below standard. This was fixed and Hubble never looked back.
Now a new asteroid hunting survey has suffered a similar set back. Pan-STARRS, the Panoramic Survey Telescope And Rapid Response System, will involve four telescopes scanning the skies with 1.8m mirrors and 1.4 billion pixel digital cameras. The aim is to snap asteroids within our vicinity of 300m or greater diameter (as opposed to the 140m or greater considered ‘threatening’ by the Near Earth Object Advisory Board…). This will be the most in depth survey of the skies for asteroids in operation, but the first telescope PS1, presently being tested has an optical fault.
The telescopes deal with the waves and motion of the atmosphere by adjusting parts of the telescope mirror in what is known as an adaptive optics system. It is believed something in the eighteen rods that do the adjustment has gone wrong. The data is 40-50% more fuzzy than it should be under this system. Initially the mirror was plagued with another problem that produced banana shaped stars near the edges and donuts in the middle, but that was solved relatively simply. Fine tuning the telescope will be a bit more arduous. The telescope and its three partners won’t be commissioned until 2012, but even so, it’d be nice having the prototype working before the others are built.
Until then, lets hope the asteroids have the decency to stay up there…