The James Webb Space Telescope, successor to NASA’s Hubble Space Telescope and the most powerful space telescope ever built, has just passed the interstellar space freeze test. After 116 days of being subjected to the most extreme temperatures, similar to those experienced in space, the heart of the James Webb Telescope as well as its sensitive instruments emerged unscathed from NASA’s thermal vacuum chamber at the Goddard Space Flight Center in Greenbelt, Maryland.
Since the complicated assembly was lowered into the vacuum chamber for the summer, teams of engineers and technicians have been on continuous monitoring duty.
One of the test directors, Engineer Mike Drury, ISIM Lead Integration and Test Engineer, was responsible with making sure that Webb will thrive in the most frigid of conditions when it finally reaches its destination in space, one million miles away from Earth.
“The telescope is going to L2 or Lagrange Point 2, which is a very extreme environment. The heart of Webb called ISIM is a very important part of the observatory and will provide all of Webb’s images.”
Images obtained with the James Webb Space Telescope will reveal some of the first galaxies forming 13.5 billion years ago, scientists say, as well as stars and planets forming in our own galaxy, photographed through interstellar dust clouds. In order to properly operate such a powerful telescope, incredibly cold temperatures are required. The Webb was tested at -387 degrees Fahrenheit (or 40 degrees Kelvin), a temperature 260 degrees colder than anywhere on our Blue Planet.
When trying to create such a cold temperature on Earth, engineers designed a massive thermal vacuum chamber at Goddard (dubbed the Space Environment Simulator) which duplicates the extreme temperatures found in outer space. The cylindrical chamber is 40-feet tall and has a 27 –foot diameter. Any traces of air are eliminated with vacuum pumps and liquid nitrogen is used to drop the temperatures to the desired point.
“We complete these tests to make sure that when this telescope cools down, the four parts of the heart are still positioned meticulously so that when light enters the telescope we capture it the right way,”
Paul Geithner, Webb’s deputy project manager said.
The heart of the Webb telescope weighs as much as an elephant.
“The biggest stress for this telescope will be when it cools down. When the telescope structure goes from room temperature to its super cold operating temperature, it will see more stress from shrinkage than it will from violent vibration during launch.”