After numerous delays, the James Webb Space Telescope (JWST) has finally passed its last revision and is ready for launch. The new jewel, a result of an international collaboration between the European Space Agency (ESA) and the Canadian Space Agency (CSA), and is on track for the scheduled launch on October 31st, 2021.
Last revision carried out in recent weeks had the task of measuring whether the mechanical forces, vibrations, and temperature variations could be compatible with such a delicate payload as James Webb. This important milestone confirms that Ariane 5, James Webb and the flight plan are ready for launch. “We are excited to have passed this important step towards the launch of Webb. We have received the green light from Arianespace and NASA“, says Peter Rumler, ESA’s project manager.
James Webb: the most powerful telescope ever launched into space
ESA, with the Ariane 5 rocket, is the carrier responsible for this delicate mission. In collaboration with its partners, ESA has been responsible for the development, qualification and adaptations of Ariane 5. The European carrier will deliver the telescope directly into a precision orbit towards its destination. The point is about 1.5 million km from Earth towards the Sun call second Lagrange point (L2).
Once in position with the thermal shield facing the Sun, the telescope will be 8m tall and as big as a tennis court. Its technology based on 18 ultralight beryllium hexagonal mirrors will allow observations in the near and medium infrared. While the 5 separate layers of Kapton, a plastic film material will shield it from solar radiation, ensuring stability to the notable thermal excursions to which the instruments will be subjected.
The choice of an infrared telescope has been well considered. Thanks to the experience gained with Hubble, it has been understood that orbiting telescopes overcome the problems related to the atmosphere that blocks or alters the light coming from space. But cosmic dust and gas from interstellar clouds are also a limitation for optical space telescopes.
James Webb’s observations will go beyond these obstacles. The telescope will allow the study of bodies in deep space, objects that are continuously moving away and more easily detected with instruments optimized for infrared frequencies. Additionally, the use of infrared will make regions of space visible that are otherwise obscured by gas and dust in visible light.