James Webb Telescope is About to Get Chilly in Cryogenic Testing

NASA’s [James Webb Space Telescope] will soon undergo intense cryogenic testing in a massive chamber at the Johnson Space Center in Houston as it prepares for its launch to space in October 2018.

The giant honeycomb-shaped satellite will spend 100 very cold days in Chamber A, aka the coldest place on Earth. Temps go down to 11 Kelvin, or about minus 440 degrees Fahrenheit, which is about the temperate in outer space.

It is able to mimic the vacuum-like conditions of space by simulating the light and heat of unfiltered sunlight, as well as the frigid temperatures within Earth’s shadow. The cylindrical chamber is 55 feet in diameter and 97 feet tall, with a 45-foot tall door on one side that weighs 40 tons. Chamber A has been testing historic spacecrafts, like the Apollo spacecrafts, since its inception in the 1960s.

The Chamber had to be modified for deep space since the James Webb Telescope will actually be in the Sun’s orbit, one million miles from Earth. It was redesigned to be hydrocarbon-free and ultra-clean, on the order of class 10,000 clean room conditions. The telescope must endure 100 days inside the chamber, which will dip to 35 Kelvin, or about minus 396 degrees Fahrenheit.

Chamber A at the NASA Johnson Space Center simulates the vacuum of space. 


The telescope itself looks like a blossoming flower of mirrors that will capture incoming infrared light from distant stars, allowing the telescope to peer beyond to planets and other objects never before seen. There are 18 segments of mirrors in total and the structure is about 21 feet wide, so it will fit nice and cozy inside Chamber A.

Once the James Webb passes this test, it will move on to Northrop Grumman Aerospace Systems in Redondo Beach, California, for final assembly and testing before launch in October 2018. The telescope will be carried to space via an Ariane 5 rocket from French Guiana and will reach its desired orbit around the sun one month later.

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