In November (or early December) of this year, NASA’s James Webb Space Telescope (JWST) will finally launch into space after many appalling delays. As the most advanced and complex observatory ever deployed, the James Webb will use its advanced suite of instruments to observe stars, exoplanets and galaxies in the near and mid-infrared spectrum. It addresses some of the most enduring mysteries about the nature of the universe.
In due course, the James Webb will fly aboard an Ariane 5 rocket from the European Space Agency (ESA) launch facility near the town of Korou, French Guiana. Overnight on August 17, 2021, the upper stage of Ariane 5 took off in its freight container from the ArianeGroup plant in Bremen to the Neustadt port, where it will board a ship for the ESA spaceport in French Guiana.
In addition to providing the launch services through its commercial partner Arianespace, ESA was also responsible for developing and qualifying the Ariane 5 adaptations for the JWST mission. This was necessary given the complexity and size of the JWST, which when fully utilized is about the size of a tennis court. In order to fit into the payload fairing of a rocket, the telescope was flipped up.
The second stage of Ariane 5 is supposed to transport a folded JWST into space. Photo credit: ESA
This is necessary because of the large sun visor that the observatory carries, which shields the extended main mirror and the tower that holds the secondary mirror. When fully unfolded, this five-layer structure measures 21 mx 14 m – or 294 m2. When folded, it measures just 10.66 mx 4.5 m (~ 35 x 15 ft) – or ~ 48 m2 (~ 525 ft2). As a result, it fits into the narrow space – 5.4 x 17 m (~ 18 x 56 ft) or 91 m2 (1,008 ft2) – of the payload fairing of the Ariane 5.
Other adjustments include new hardware that keeps the vents around the base of the payload fairing fully open. This is to minimize the pressure release shock when the two halves of the fairing drop away from the launcher after the second stage carry the James Webb above the Earth’s atmosphere. In addition, the Ariane 5 will perform a specially developed roll maneuver to protect the telescope from solar radiation and heat caused by friction with the atmosphere.
In addition, the Ariane 5 carries an extra battery so that the upper level can receive a boost after the telescope is triggered, so that it has an extra distance between it and the James Webb. The observatory will also be integrated via a launcher adapter ring that could be used by future spacecraft to grab the observatory and correct its orbit (in case there are any problems with the deployment).
The upper stage of Ariane 5, which will transport the JWST, will be transported from Bremen to Neustadt on August 17th. Credit and ©: ArianeGroup
Once in Neustadt, the second stage goes on board the cargo ship MN Toucan, where it joins the other elements of the launcher and continues its journey to South America. According to the latest statements by officials from NASA’s Science Mission Directorate (SMD), the telescope will be shipped to the launch site later this month (possibly sometime in September). From that point on, it will take 10 weeks for the telescope to be ready for launch, with 55 days alone required to load it onto the rocket.
Compared to its predecessor, the venerable Hubble space telescope, the James Webb is significantly larger. Its main mirror measures about 6.5 (21.3 ft) in diameter, about 2.75 times larger and about six times the size of Hubble’s. But while Hubble weighed around 12,250 kg (27,000 lbs), the James Webb will weigh a little over half that – roughly 6,500 kg (14,300 lbs).
The James Webb is the result of decades of hard work and development by scientists as well as a lucrative international partnership between NASA, ESA and the Canadian Space Agency (CSA). Once operational, it will become the premier observatory for the next decade, serving thousands of astronomers worldwide and enabling all kinds of breakthroughs in our understanding of the universe and the physics that govern it.
The JWST will enable some truly amazing astronomical and cosmological studies. Photo credit: NASA
Its suite of advanced optics, IR imaging capabilities, spectrometers, and coronagraphs will enable astronomers to characterize the atmospheres of exoplanets, which is key to determining whether or not they could or may not support life as we know it. It will be able to look back to the earliest periods of the universe (also known as the “cosmic dark ages”) and see the first galaxies when they were still forming.
It will also be used to study star systems in the process of formation and provide valuable clues as to how systems that are capable of supporting life were formed. Here at home there will also be valuable insights into the evolution of the solar system, the types of objects that populate the Kuiper Belt, and study bodies such as Europe and other “ocean worlds” (which may harbor their own life forms!)
For these reasons, there is no shortage of scientists and ordinary people who can’t wait for it to get into space so that it can start its work!
Further reading: ESA