Finally ! A month following taking off from Kourou, Guyana, the James Webb Space Telescope is due to arrive at its destination on Monday, January 24. After a third and final maneuver, the machine should enter orbit at the second Lagrange point, L2, 1.5 million kilometers from our planet. James Webb will not be alone on the spot, since it is also there that the European observatory Gaia is located, which identifies and catalogs celestial objects since 2014.
→GRAND FORMAT : James Webb Telescope: in search of the origins of the universe
“In this position, the James Webb Telescope will revolve with the Earth around the Sun and not around the Earth, as the Hubble Telescope does., described Pierre Ferruit, co-responsible scientist for the European Space Agency, during the launch last December. Unlike Hubble, which cannot observe permanently, the entire sky will be accessible over the course of a year with James Webb. »
One of the best Ariane 5 launches
Once at destination, five months of commissioning are planned: a period during which the telescope and all its instruments will be tested, before launching the collection of scientific images in the summer of 2022. Planned to last regarding ten years , the telescope’s mission should actually be able to last almost twenty years, according to NASA engineers.
→ ARCHIVES. 40 years ago, the first Ariane rocket took off
The reason ? A perfect launch from Ariane 5, the flagship of French space. As the story goes the specialized site Ars Technica, the engineers and technicians involved throughout the production line of Ariane 5 rocket components each time set aside the best machined part, specifically for the rocket that carried the James Webb. This involvement of industrial know-how allowed the planned trajectory to stick to the ideal trajectory. And therefore fewer small propulsions to align the telescope at point L2, saving fuel.
A need for fuel to maintain orbit
Because if the scientific instruments of the James Webb are powered by solar panels, the machine still needs fuel to maintain its position in space. The telescope will indeed not be exactly at the Lagrange point, which is stable, but in orbit around it. Orbit that must be constantly readjusted, thanks to thrusters. At 1.5 million kilometers from Earth, no resupply mission is planned.
To communicate with their protege so far away in the earth’s shadow, the specialists rely on steerable radio antennas on the telescope and on the “Deep Space” network on Earth. The operations, carried out from Baltimore in the United States, bring together international teams who take turns 24 hours a day, 7 days a week.
Ultimately, this international project should make it possible to learn more regarding the first hundreds of millions of years of the Universe, with the formation of stars and galaxies, but also regarding exoplanets and their atmospheres.
