Will the Jwst ever launch?
Beset by delays and with costs rising, the government may pull the plug
NASA scientists join a debate about the delayed telescope
When NASA began work on its nextgeneration Space Telescope in 1996, six years after Hubble had been launched, there was great excitement among scientists that space was about to get ever closer.
Here was a plan to position a gigantic space observatory near the Earth-Sun L2 Lagrangian point, some 1.5 million kilometres (932,000 miles) away from Earth. With seven-times the lightcollecting power of Hubble, it was envisaged it would be an advanced time machine of sorts, allowing astronomers to peer back like never before and uncover wonderful nuggets about our universe that, up until now, have frustratingly evaded us.
What nobody foresaw some 23 years ago, however, was just how distant those plans would become. In that time the complex structure that was renamed the James Webb Space Telescope (JWST) in 2002, after NASA's second administrator, has been beset with problems and delays. It still
hasn't been launched, and the infrared-optimised telescope may not even get off the ground at all.
In many ways that sounds crazy, given the amount of time and effort that has already been invested. But, judging by the noises coming from the American government, the project will not be allowed to turn into a money pit. The JWST started with a budget of just $0.5 billion in 1996, but it has certainly snowballed since then. In 2001 the United States Congress rubber-stamped a pre-launch cap of $8 billion, yet costs have now smashed through that ceiling to $8.8 billion.
That has led to some alarm among America's top brass amid fears the costs could increase further. To that end NASA has been provided with $21.5 billion within the Commerce, Justice and Science spending bill, but while that includes $304,600,000 for JWST, an accompanying report expressed “profound disappointment with both NASA and its contractors regarding mismanagement, complete lack of careful oversight and overall poor basic workmanship”. It was, in a nutshell, rather damning.
But just how has it come to this? If the report is to be taken at face value then “NASA and its commercial partners seem to believe that congressional funding for this project and other development efforts is an entitlement, unaffected by failures to stay on schedule or within budget”. The truth, however, is much more complicated than a claimed lazy attitude, but NASA certainly has to tread carefully. Should it not adhere to the new cap of $8,802,700,000, “JWST will have to find cost savings or cancel the mission” and, for science, that would be devastating.
Had everything gone to plan, JWST would have launched by now. The original timeframe was October 2018, but it has slipped numerous times, first to spring 2019, then to May 2020 and now to March 2021 – a decision taken last June when it emerged there had been an acoustics test anomaly.
One of the big issues has concerned the use of a sunshield, one of the two vital components of this project – the other being the telescope itself.
The sunshield is the size of a tennis court and is made up of a five-layer membrane, each one cooler than the one below. Composed of heat-resistant Kapton and coated with aluminium, their role is to deflect the Sun's light rays, allowing the mirrors to be kept below -220 degrees Celsius (-364 degrees Fahrenheit) and ensuring readings are not distorted.
Unfortunately this complex structure is also prone to tearing, as engineers have found to their – and the JWST's – cost. When they discovered the sunshield was unfurling, folding and stowing much more slowly than desired they also noted there was too much slack on the cables. The sunshield got caught on these, and it tore as much as ten centimetres (3.93 inches) of the material. There were seven rips in total and, as if that wasn't enough, there were also some leaky valves within the spacecraft's propulsion system to contend with.
Under normal circumstances problems such as these could be sorted after a telescope has been deployed, but JWST is going to be so far from Earth
“Had everything gone to plan, JWST would have launched. The original timeframe was October 2018”
that sending robots on repair missions simply isn’t an option. It's why problems are causing extremely lengthy delays – this is a one-shot mission. Should it go wrong once it's comfortably in position and the sunshield is unfurled, it really would spell the end.
That, of course, would be a real shame for science. JWST comprises 18 hexagonal segments that make up a 6.5-metre (21.3-feet) primary mirror made of beryllium, making it powerful enough to be able to peer at some of the first stars and galaxies which appeared in the universe. What's more, the telescope will also give a greater insight into potential signs of life in the atmospheres of nearby exoplanets. Able to observe from visible red/orange to mid-infrared, it can pick up on highredshift objects. But none of that will be possible if it remains on the ground.
Luckily there is a great desire to see it lift off. NASA administrator Jim Bridenstine said: “Webb is vital to the next generation of research beyond NASA's Hubble Space Telescope. It's going to do amazing things – things we have never been able to do before – as we peer into other galaxies and see light from the very dawn of time.”
It was also heartening that the Independent Review Board (IRB), as recently as July, recommended development should continue. Thomas Zurbuchen, associate administrator of NASA's Science Mission Directorate, said it meant JWST's total lifecycle cost is now likely to top
$9.66 billion, but he drew attention to the “exceptional potential and science insight” the telescope will promise.
“Webb's world-class science,” he wrote, “will underpin many other astrophysics projects that will use its high-calibre capabilities to enhance their science return.” And yet there remains a need to step up a gear. The telescope's primary contractor Northrop Grumman came under fire when it emerged human error caused the wrong solvent to be used when cleaning a fuel valve. Excessive voltage was also applied to transducers thanks to incorrect wiring: mistakes that racked up the price and caused delays.
The IRB also drew attention to the complexity of the systems, a lack of experience in areas such as sunshield development, embedded problems and excessive optimism. It has become clear that NASA didn't really have a handle on the costs from the start, but that has tended to be the case with such things. Indeed, Hubble cost six-times the original projection of $200 million.
NASA, however, must now take on a greater role in overseeing the project and check test reports daily and weekly. The good news is that all of the technologies needed for the project have now been invented – something that wasn't the case at the start – so the project should from this point on be purely about perfecting the systems.
It is also worth bearing in mind that, even at $8.8 billion, the telescope is something of a bargain for the results it should bring. In the fourth quarter of the fiscal year 2018 Apple raked in $62.9 billion from the sale of iPhones alone: and, try as you may, you'll never detect light from the first stars and galaxies using one of those.