This year marks the 30th anniversary of the Hubble Space Telescope. When you see all the great pictures today, it is hard to remember that when it first launched, it was nearly a failure, taking fuzzy pictures. The story of how that problem was fixed while the telescope was whizzing through space is a good one. But there’s another story: how did a $1.5 billion satellite get launched with defective optics? After all, we know space hardware gets tested and retested and, typically, little expense is spared to make sure once a satellite is in orbit, it will work well for a long time.
The problem was with a mirror. You might think mirrors are pretty simple, but it turns out there’s a lot to know about mirrors. For astronomy, you need a first surface mirror which is different from your bathroom mirror which almost certainly reflects off the back of the glass. In addition, the mirrors need a very precise curve to focus light.
Perkin Elmer — a name you don’t hear much anymore outside of the medical field, used to make many kinds of things including computers after they acquired Interdata. However, they also had a history working with optical systems, including for the KH-9 spy satellite. They were in charge of building and testing the Hubble’s mirror. It was off by about 2 micrometers. That doesn’t sound like much, but when you are focusing light — especially light from billions of miles away — it is a lot.
How Bad Was it Really?
Here are two pictures of the M100 galaxy taken by the Hubble. You can ..
Support the originator by clicking the read the rest link below.
