Richmond company helping build the next space telescope
By Shelly Meron
Contra Costa Times
Posted: 07/17/2011 07:40:02 PM PDT
Updated: 07/17/2011 07:40:55 PM PDT
Robert Garfield, a manufacturing process engineer, points to a 650-pound secondary telescope...
A little piece of Richmond will blast off into space in 2018.
Make that 18 hexagonal pieces of beryllium mirrors, made and polished by the Richmond-based company L-3 Tinsley. The flashy pieces will make up the new James Webb Space Telescope, the successor to the world-famous Hubble.
The company "is very proud to have been selected to manufacture the main telescope mirrors," and to complete the job three and a half months early, John Kincade, vice president and general manager, said Friday. Tinsley has been working on the project since 2003, and the firm completed the mirrors just last month. The company was chosen to work with Northrop Grumman Aerospace Systems, the main contractor for NASA on the Webb telescope, because they had the most experience making such mirrors out of beryllium, a lightweight metal mined in Utah.
The new telescope will allow scientists "to see things that no human has seen, as far back as physically possible," said Scott Texter, Northrop Grumman's telescope manager.
That includes studying planets orbiting other stars, or finding water in the atmospheres of "super Earths" -- planets with masses ranging between Neptune and Earth.
Mirrors are used in some telescopes to reflect light and capture an image of a faraway, sometimes dim object. With the Webb telescope, a primary mirror acts as the reflector while a secondary mirror directs the image back to the scientific instruments that collect data. Beryllium was chosen because it is light enough to ship into space, but still hardy enough to retain its shape in extreme temperatures.
The process of making the mirrors began when Tinsley got a large chunk of beryllium after it was mined, ground up into fine powder and purified, put into a pressure cooker-type machine and made into a solid block. The resulting slab was about 2 inches thick, 5 feet in diameter and weighed 600 pounds.
Workers removed most of the weight and the resulting chunk of beryllium was only 40 pounds and 1 millimeter thick -- light enough for a trip to space.
That's when Tinsley employees got the beryllium and began a precise method of polishing to get the metal within 10 nanometers -- one nanometer is one billionth of a meter -- of the perfect mathematical shape.
"We're basically removing a few atoms at a time at that level," Texter said. At this point, he added, the mirrors are still "a thousand times the wrong shape."
That's because the telescope has to function at 440 degrees below zero Fahrenheit. Since an object's shape changes depending on the temperature, if the mirrors are the correct shape at room temperature, they will be off when placed in the colder environment.
So after testing the metal hundreds of times in room temperature and polishing a bit at a time, Tinsley workers cooled it down in a test container, and polished it to make the necessary adjustments.
The 18 resulting mirrors will be assembled into one large mirror and installed on a truss-like structure. A tripod, secondary mirror and other scientific instruments also will be added.
The whole thing is tested again in cryogenic temperatures at the Johnson Space Center in Houston before a sun shield and space craft are attached.
And in 2018, Texter said, "We fold it up, stick it in a rocket and push a button," sending the new Webb telescope into space.