Hubble successor’s perfect start on its month-long 1.5 million km journey
A new window is about to open on the Universe after the launch of the James Webb Space Telescope (JWST) on 25 December 2021 at 12:20 UT. The telescope is a 6.5m-wide infrared space observatory that will be able to view the cosmos in precise detail – from the atmospheres of our neighbouring gas giants to galaxies on the edge of the Universe.
Though predominantly a NASA mission, the spacecraft was launched successfully from Spaceport Europe in French Guiana by the European Space Agency, on board an Ariane 5 rocket. At an altitude of 1,400km, the observatory and rocket separated and JWST released its solar panels a few minutes later. The telescope will spend the next 30 days travelling to the second Lagrange point (L2), a gravitational stable region 1.5 million km from Earth.
However, as the telescope was folded up to fit inside the rocket, it has undergone the most complex deployment ever attempted in space, with up to 50 separate stages. The most fraught of these is deploying the sunshield – five layers of Kapton foil, each the size of a tennis court but only 50 micrometres thick – that keeps the telescope cool. The sunshield boom deployed on 1 January, before being pulled tight over several days (with a brief delay to optimise the space observatory’s power systems).
The main mirror began deployment on 5 January, with the deployment of the primary mirror’s outer petals due a few days later (after this issue went to press).
The JWST is expected to reach L2 on 23 January, where it will spend six months checking systems and calibrating itself, before it begins scientific observations in around six months time. https://webb.nasa.gov/
Comment by Chris Lintott
My attempt to take a break from social media over Christmas has been ruined by refreshing the @NASA_Webb and @esa_Webb twitter feeds for updates on the JWST deployment. The rule is not more than once an hour, but it’s hard to be sure you’re up to date when looking beyond the official sources often pays off –a legion of astrophotographers is keeping an eye on the precious telescope, reporting a significant increase in brightness as the sunshield deployed.
There’s been little drama, with the biggest news being that the JWST team took a day off over New Year. I hope they spent it relaxing; what they’re doing really could change our view of the Universe for ever, as well as my Twitter habit!
Chris Lintott co-presents The Sky at Night