A Mirror Milestone

• By Maggie Masetti
• September 28, 2012
• 1 Comment

The James Webb Space Telescope, the scientific successor to the Hubble, will be the most powerful space telescope yet! This is partly due to Webb’s enormous primary mirror, which will have 18 segments that will work together as one.

The flight primary mirror segments were recently completed, which means they went through multiple rounds of cryogenic testing, in addition to being polished and coated in very thin layer of gold. The gold coating, which is only 1000 angstroms thick (and equivalent to about 50 grams of gold or ~10 wedding rings) will optimize the mirrors for observation of infrared wavelengths of light. Because to avoid swamping the very faint, distant infrared astronomical signals with heat from the telescope, the telescope and its instruments must be very cold – thus the cryogenic testing at nearly every phase of construction!

The completed mirrors were recently packed up in special shipping cans (you can see all 18 of them here), which also gives you an idea of the scale of this telescope!

Credit: Ball Aerospace

The first two of these flight mirror segments just arrived at NASA Goddard and were delivered to our cleanroom.

What does it look inside one of these cans? We’ll have another upcoming blog post with pictures of the techs opening the cans and inspecting the mirrors – but we can show you what the flight spare mirror segment looked like in its shipping can. Shiny!

Credit: Drew Noel

Here’s a view inside the truck at the two mirrors in their cans, awaiting unloading at NASA Goddard:


Credit: NASA/Chris Gunn

Next, the mirrors were (carefully) unloaded using a forklift – wonder how nervous that driver was!

Credit: NASA/Chris Gunn

Here, four technicians moving the two mirrors in shipping canisters (cans) through the building that houses NASA’s giant clean room. Fittingly, one of the technicians (left) is wearing a shirt that pictures NASA’s Hubble telescope.

Credit: NASA/Chris Gunn

A technician gives the cans a thorough check to ensure no damages occurred during their travel from Ball Aerospace & Technologies Corp. of Boulder, Colo. who manufactured the mirrors and packed them.

Credit: NASA/Chris Gunn

And then the mirrors were wheeled into our cleanroom!

Credit: NASA/Chris Gunn

Stay tuned and we’ll have more coverage of this important milestone for the James Webb Space Telescope! If you’d like to learn more, you can visit the project’s website and you can also see what’s going on in the cleanroom live on the “Webb-cam.”