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View Full Version : Tiny Shutters in the James Webb Telescope Improve its Vision



Fraser
2007-Jan-26, 01:53 AM
NASA has a new article on their site describing one of the technologies going into the mighty James Webb Space Telescope; the successor to the Hubble Space Telescope. ...

Read the full blog entry (http://www.universetoday.com/2007/01/25/tiny-shutters-in-the-james-webb-telescope-improve-its-vision/)

milk
2007-Jan-27, 10:10 PM
I wonder how they are going to maintain those 62,000 shutters. If many of those lock up, I would expect worse performance from the telescope.

suitti
2007-Jan-29, 04:22 PM
Once the Webb goes up, that's that. My guess is that the whole shutter system can be removed from the light path, and it's only used when needed.

One might think that an LCD grid could have been used. However, LCDs have trouble with cold. I was out the other night with my scope. I use my Palm Pilot for star charts. It was pretty sluggish in the 20 degrees F (-6 C). So, i need some way to get it back into my shirt pocket.

From the description, my guess is that these things are either going to work or not. As long as they don't get contaminated. There may be wear with each use, but it's not going to be incredibly high use. My guess: you take a deep shot, then take a second one with some of the shutters closed. I bet most shots don't use it.

trinitree88
2007-Jan-30, 09:49 AM
[QUOTE=suitti;914984]

One might think that an LCD grid could have been used. However, LCDs have trouble with cold. I was out the other night with my scope. I use my Palm Pilot for star charts. It was pretty sluggish in the 20 degrees F (-6 C). So, i need some way to get it back into my shirt pocket.

Suitti. Try one of those catalytic handwarmers for skiers and snowmobilers...50 cents, works for hours, gives about 120F..iron-iron oxide. Keep your Palm pilot toasty. A little insulation will temper the admittance of the air(oxygen supply)...and keep your hands toasty too, without creating too much of a local thermal near your scope. Wal-Mart 3/2 bucks.Sporting goods. pete