Cryocooler of The James Webb Space Telescope

This image depicts the cryocooler, a cooling apparatus designed specifically for the Mid-Infrared Instrument (MIRI) - one of the four instruments on the James Webb Space Telescope. The MIRI needs to operate at a lower temperature than the other instruments, and the cryocooler facilitates this requirement. Credit: NASA/JPL-Caltech. 

The James Webb Space Telescope (JWST) is set to revolutionize our understanding of the universe. Launched in 2021, the telescope is designed to detect the faintest signals from the most distant objects in the cosmos. To achieve this, the JWST is equipped with some of the most advanced technology ever developed, including a cryocooler.

In this article, we will explore what a cryocooler is, why it is necessary for the JWST, and how it works.

What is a cryocooler?

A cryocooler is a device that cools objects to very low temperatures, typically below 100 Kelvin (-173.15 Celsius or -279.67 Fahrenheit). Cryocoolers are used in a variety of applications, including in the medical and aerospace industries. In the case of the JWST, the cryocooler is necessary to cool the telescope's mid-infrared instrument (MIRI). This instrument is sensitive to the faintest heat signals from distant objects, but it must be kept extremely cold to function properly.

How does the cryocooler work?

The cryocooler on the JWST uses a Stirling cycle engine to cool MIRI. The Stirling cycle engine is a type of heat engine that uses a piston to compress and expand a gas, which causes the gas to heat up and cool down. This heating and cooling process is used to transfer heat away from the instrument and into space. The Stirling cycle engine is powered by solar panels on the JWST. These panels generate electricity, which is used to drive the engine. The cryocooler also uses a heat exchanger to transfer heat away from the instrument and into space.

Why is the cryocooler necessary for the JWST?

The JWST's MIRI instrument must be kept extremely cold to detect faint heat signals from distant objects. Without the cryocooler, MIRI would quickly warm up to the point where it would no longer be able to function properly.

The cryocooler is also necessary to keep the JWST's other instruments cool. The telescope itself is shielded from the sun by a sunshield, but it still absorbs some heat from the sun and from the warm spacecraft electronics. The cryocooler helps to keep the entire telescope at a stable temperature.

The cryocooler on the JWST is a crucial component of the telescope's advanced technology. It is necessary to keep the MIRI instrument and the entire telescope at extremely cold temperatures to detect faint heat signals from distant objects. The cryocooler uses a Stirling cycle engine and a heat exchanger to transfer heat away from the instrument and into space. With the cryocooler, the JWST will be able to make groundbreaking discoveries and revolutionize our understanding of the universe.