At Europe’s Spaceport near Kourou in French Guiana, technicians are busy getting the James Webb Space Telescope (JWST) ready for launch. The observatory arrived at the facility on Oct. 12th and was placed inside the upper stage of the Ariane 5 rocket that will carry it to space on Nov. 11th. The upper stage was then hoisted high above the core stage and boosters so that a team of engineers could integrate them.
Unfortunately, an “incident” occurred shortly after when the engineers attempted to attach the upper stage to the launch vehicle adapter (LVA) to the launch vehicle. According to a NASA Blogs post, the incident involved the sudden release of a clamp band (which secures the JWST to the LVA), which sent vibrations throughout the observatory. According to NASA, this incident could push the JWST’s launch date (slated for Dec. 18th) to Dec. 22nd.
A NASA-led anomaly review board was immediately convened to investigate the unexpected development and recommend how to proceed. The board recommended that additional testing be instituted to “determine with certainty” that the incident did not damage any components. NASA also indicated that it and its mission partners would provide an update when the testing is completed, which is expected to be by the end of this week.
The second stage of the Ariane 5 is ideally suited to transporting the JWST to space. Credit: ESA
In the meantime, these additional tests mean that the JWST will not make its target launch date of Dec. 18th. But that is not surprising given the telescope’s development history, which has been plagued by delays from the beginning. Development efforts began in 1996 with an initial plan to launch by 2007, but delays and cost overruns meant that the observatory was not finished construction until 2016.
Further delays occurred in 2018 when a section of the Sun Shield ripped during a practice deployment and again in March 2020 due to the pandemic. Once work resumed, a launch date of Oct. 31st was selected but was delayed yet again due to concerns over the Ariane 5 launch vehicle. These concerns were due to issues experienced during two previous launches, where the vehicle accelerated unexpectedly during rocket-fairing separation.
Despite these anomalies, the Ariane 5 rocket has a solid reputation for safely sending payloads to space. Since 1996, 111 launches have been made using this launch vehicle, and only five were unsuccessful (two failures and three “partial failures”). That’s a 95.5% success rate, which is nothing less than excellent. But given the precious nature of the cargo, there can be no room for doubt when the JWST launches.
As of the writing of this article, the date for Webb’s launch stands at Dec. 22nd at the earliest. Once additional tests are complete and the JWST and upper stage are given a clean bill of health, the Webb and Ariane 5 engineering teams will resume their efforts prepping the telescope for launch. This will culminate with the Webb and Ariane 5 teams uniting for the final integration of the upper stage to the core stage and boosters, then launch.
A primary mirror segment of the James Webb Space Telescope, made of beryllium.
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