Image credit: NASA/Desiree Stover
Updated Dec. 22, 2021: The launch date of JWST has been postponed due to weather from Dec. 24, 2021 to Dec 25, 2021 at 7:20am EST. The article below has been edited.
When the Hubble Space Telescope launched into orbit around the Earth in 1990, the first images were blurry. It had launched with a flaw in the mirror – one that made the curve off by a width of 1/50th of a single sheet of paper.1 That tiniest of flaws made the $1.5 billion telescope nearly useless. A servicing mission was sent up three years later on a space shuttle, when astronauts installed a new optics package to correct the problem. Since then, it has taken thousands of the most stunning and scientifically groundbreaking images we have ever seen of our universe.
When Hubble’s successor, the $11 billion James Webb Space Telescope (JWST) launches this Friday, it will have no opportunity for service missions to fix flaws in its mirrors. It’s not going to low earth orbit (LEO) like Hubble, it’ll be headed for Lagrange Point 2 – a gravity-balanced orbital parking spot some 1.5 million km away from Earth.2
JWST’s mirror is three times the width of Hubble’s, allowing it to see further and more clearly into the depths of the universe.3 But that heft also presented a massive operational challenge for NASA. Launching a telescope the size of JWST has never been done before and everything needs to be right the first time. The sheer complexity of this project resulted in multiple delays, repeatedly pushing projected launch dates from the originally scheduled launch in 2007 all the way to Christmas Eve Day, 2021.4
Constructing the World’s Most Advanced Telescope
The problem with launching a 6.5 metre wide telescope into space is that there are no launch vehicles capable of carrying something that wide. The JWST team had to get creative, designing a new type of mirror that could be folded into a compact shape for launch and then be able to unfold itself once at the correct orbital point.5
Animation of telescope deployment. Credit: NASA’s Goddard Space Flight Center Conceptual Image Lab6
Beryllium, a rare metal NASA mined in Utah, was used for the 6.5m mirror, drastically reducing the weight of the telescope while improving resistance to warping in the extreme temperatures of space. The five-layered, kite-shaped shield that protects the telescope and its data includes several advances in materials engineering. Technology was invented specifically to enable JWST to make its own in situ calibration and focusing adjustments to within 1/10,000th the width of human hair.5,7
In all, ten brand-new inventions were required to create the world’s most advanced telescope – new technologies that have already begun to be recycled for use in medical, manufacturing and scientific applications.10 New ideas to overcome challenges never before seen; challenges causing 14 years of launch delays and spanning, in some cases, whole careers.
The Long Road to Launch
Construction of JWST was finished in 2016, but the telescope’s journey was far from complete. It suffered several years of testing delays before the telescope was finally declared ready for launch with a date set for October 31, 2021.11 Unfortunately, even though the telescope was finally ready, the launch vehicle was not.
The Ariane 5 booster rocket is a major contribution to the JWST project from the European Space Agency (ESA).12 It is the only launch vehicle currently capable of launching such a heavy load intended to travel such a great distance. And until Fall 2021, it had been grounded for a year due to an issue with its payload fairings.11 Luckily, this issue was fixed within a short window and the launch was rescheduled to December.
With the rocket and the telescope ready, it was time to put them together. Transporting a 6,200 kg, $11 billion space telescope from Northrop Grumman in California to the Ariane 5 launch site in Kourou, French Guiana was no small feat. To get there, the telescope had to be packed in a transportable ‘suitcase’ called STTARS, and shipped nearly ten thousand kilometers by sea through the Panama Canal to the northeastern corner of South America.12
STTARS is the specially-engineered Space Telescope Transporter for Air, Road and Sea. Essentially a custom-built shipping container, it was already used for JWST several times during its construction stage, including transporting section pieces from Houston to California for final assembly. For that journey, it had to be trucked to an airfield where the whole truck and trailer system was pulled, inch by painstaking inch, onto the largest transport aircraft in the US military via an electric winch before being flown to Los Angeles.13
STTARS using its hydraulics to unload from a cargo plane. Credit: NASA/Mike McClare14
The container, at 175,000 kg, weighs over ten times the telescope it carried. Acting as both transport protection and a mobile clean room, it’s been equipped with environmental controls and a hydraulic system for raising and lowering the trailer.
Every road, bridge and intersection had to be analyzed and driven ahead of time by the telescope’s logistics and launch site processing manager, Charlie Diaz. He and his team picked the routes based off of satellite imagery, then arranged for police escorts to help them conduct field surveys to ensure the roads would be safe for STTARS and its precious cargo. Where the routes were left wanting, Diaz’s team made recommendations for improvements, and many a pothole has JWST to thank for being filled. Pull-off points were identified throughout the route for safe maintenance, should it be needed, or for the team to stop if outside the STTARS restrictive travel hours (it could only travel between midnight and 6am at speeds limited to less than 16km/h). At double the length of a standard tractor trailer and a massive weight, not every bridge and intersection makes the cut when it comes to accommodating the route. Some street lights even had to be lifted so the telescope could pass safely underneath.
For the final leg of its journey on Earth from California to French Guiana, it only needed to traverse by land to and from ports and facilities on either end of the journey – the bulk of the route, 9,300 km, was by sea aboard the MN Colibri. The journey by air would have been faster, but the road from the local airport to the launch site was much farther and required seven bridge crossings – bridges not built to withstand the weight of STTARS. The MN Colibri was purpose-built for transporting rocket parts and was the ideal delivery system for JWST, requiring only a very short drive on either end of the voyage.
To load STTARS and the telescope it carried onto the ship, the truck and trailer system first had to be loaded onto a barge at Seal Beach, California. A tugboat carefully rotated the barge to line up with the MN Colibri‘s cargo ramp before the truck could slowly back up into the ship’s hold. A reverse of the process would happen after its 16 day voyage through the Panama Canal.15
Sandra Irish, lead structural engineer, helped chart the special sea route to avoid rough seas and heavy rocking that could damage the cargo.12 The route not only included natural risks but could also be targeted by opportunistic pirates, for whom the telescope would have been a valuable hostage. Several security measures were taken to obscure both the identity of the ship and the shipment date to thwart potential bandits from holding the telescope for ransom.16 Full security measures have not been revealed to the public but have been speculated to include decoy ships and naval escorts.
Space pirates aside, JWST arrived safely in French Guiana on October 12. It has spent the last two months running through final tests and being (carefully) hoisted onto the Ariane 5 booster.17 As of this article’s writing, it sits atop its rocket awaiting liftoff in the early morning hours of Christmas Eve Day. Assuming no more delays or reindeer-related launch complications, this is still just the first step in its incredibly complex journey.
Thirty Days of Terror
After the launch, JWST will undergo a complex series of maneuvers to reach its orbital destination and deploy its instruments, the whole process taking about a month.18 Because of the complexity of the sequences, the inventiveness of the technologies and the complete lack of safety net, the global astronomy community will be collectively holding its breath until full deployment is achieved.
When it is fully deployed, calibrated and comfortably in orbit 1.5 million km from home, JWST will finally be able to begin to realize its true purpose. After twenty-five years of work and innovation and budget wrangling, after ten thousand kilometers by sea and a long-awaited liftoff on Christmas Eve Day, after thirty days of terror and months of final calibrations, it can finally give us the gifts those first scientists wished for – a vision of the early universe, a glimpse at solar systems as they are born, a breath of an extraterrestrial atmosphere as an alien sun shines through it.
