Flight control turned on the telescope’s motors for 297 seconds on Monday, exactly as planned. As a result, the speed increased slightly, just enough to ‘park it in’. The James Webb now flies in a stable place in the shadow of the earth and orbits the sun with the earth. It uses as little energy as possible there, has an unobstructed view of the universe and can easily send images and measurements.
The James Webb is the successor to the famous Hubble Space Telescope, which has been operating since 1990. His end is near. That is why Europe, the United States and Canada have developed the new telescope. From the Netherlands, Leiden University and research institute TNO are involved in the project, among others.
Tennis court
The new space telescope is about the size of a tennis court. The core is a 6.5-meter mirror, six times the size of the Hubble. That mirror was flipped open two weeks ago. It captures the light from space and reflects it to a second mirror, which bundles the light and sends it to the measuring instruments on board. The main mirror consists of eighteen hexagons that sit together, but can move independently of each other to focus. The mirror is made of beryllium, with a tiny layer of gold 100 nanometers thick on top. That’s a thousand times thinner than a human hair or a sheet of paper. Beryllium is light, strong and can withstand extreme cold. The gold ensures that the mirror is better able to see infrared light.
Among other things, the James Webb has to search for planets where life might be possible, distant galaxies and traces of the Big Bang. It can see a billion years further back in time than Hubble. At his workplace far away from the sun, the temperature is 233 degrees below zero. This extreme cold makes the measurements more accurate and reliable. The project will cost a total of approximately 8 billion euros.
The James Webb can’t get started right away. One of the measuring instruments on board must be cooled to 266 degrees below zero. That takes about a month. After that, it takes a few months to test if everything is working properly. The James Webb will probably be able to take the first measurements in the summer.