The James Webb Space Telescope awaits its heat shield – South West

Le James Webb Space Telescope is not at the end of the road and the technicians of the Space Telescope Science Institute from Baltimore (Maryland, on the east coast of the United States) are not done with stress.

Several essential stages mark the long course of the observatory towards the point of Lagrange L2, 1.5 million kilometers from Earth, or four times the Earth / Moon distance. This December 28, three days after the launch operated by Arianespace from Kourou, Guyana, the deployment of the telescope’s heat shield is due to begin.

>> Follow the James Webb telescope on the official NASA website

This equipment is essential for the correct functioning of the device. This will scan the universe with its back to the Sun, in the shade and (almost) absolute cold, at -266 ° C. It is the temperature required to observe in the infrared, the wavelength in which the on-board instruments are specialized – in particular MIRI, the tool with a strong European contribution which will be able to look through clouds of gas and dust.

Five thin reflective layers

James Webb’s heat shield is made up of five distinct thin layers. For the moment, they are folded into an accordion in the cocoon of the observatory. The first phase of their deployment will begin. If all goes as hoped, the shield will be stretched like a sail in a few days. Its size will be around that of a tennis court. The unfolding of the mirror itself will then be able to engage.

Last night the second telescope course correction was made. It was shorter (9 min and 27 sec) than the first which took place immediately after the launch phase. The observatory is now sailing more than 450,000 kilometers from Earth at nearly 4000 km / h. He has shot more than 30% of the distance between him and his destination. But he will only reach it after a month. It will then take long weeks of “calibration” of the instruments before scientific observations begin, normally next June.