NASA has announced yet another delay for the launch of the James Webb Space Telescope (JWST), following the publication of a report from the Independent Review Board (IRB) set up to assess the progress of the project in the wake of multiple setbacks. The flagship telescope will now launch no earlier than March 30, 2021, and is expected to significantly overrun the US$8 billion development budget allotted by Congress.
Once launched, the JWST will represent the most powerful and complex orbital observatory ever put into service. It will be capable of performing a vast array of tasks, from capturing the light emitted by the very first stars to populate the cosmos, to exploring the atmospheres of distant exoplanets for signs of life.
However, for these scientific wonders to be achieved, the telescope has to be, well, launched. The road to launch has been characterized by numerous delays and ever-increasing cost, due in part to the technical issues synonymous with building a telescope of this incredible complexity, paired with a significant amount of human error.
When designing and building a flagship space telescope such as the Hubble Space Telescope or the even more complicated JWST, mission success is critical. The worst-case scenario for NASA is to put a broken telescope into orbit. This is essentially what happened to Hubble, which was lofted into space with an imperfectly ground main mirror, requiring multiple rescue and servicing missions to remedy.
The difference here is that whilst Hubble orbits the Earth at a trifling distance of 547 km (340 miles) from the surface, the JWST, once in its final orbit, will actually orbit the Sun at a location known as Lagrange Point 2, which will place it some 1.5 million km (1 million miles) from our Blue Marble. As if the distance alone isn't troublesome enough, NASA has no spacecraft at its disposal with which to mount a rescue sortie, so best to get it right before the asset reaches the launch pad.
To avoid a catastrophe, exhaustive ground-based testing is the way to go. Unfortunately, this has a nasty habit of bringing new problems to light, but as previously discussed, better that this happens in a controlled environment rather than in the troublesome vacuum of space.
Since its original launch date back in 2007, numerous technical problems and myriad other issues have forced T-0 back again and again. Prior to today's announcement, NASA had been targeting a launch date of May 2020. The new March 2021 launch date takes into account the findings of the IRB, as well as existing delays, caused in part by a serious issue that emerged during acoustic testing of the spacecraft element.
During the acoustic test, which is intended to simulate the stresses that will be experienced by the spacecraft during launch, fastening hardware designed to hold the sunshield membrane in place came loose. The tennis court-sized sunshield is one of the most vital parts of the whole spacecraft, as it protects the telescope and delicate scientific instruments from the heat of our star. Rectifying this fault alone is estimated to have added about six months to the testing schedule.
The newly-published IRB report identifies a number of factors influencing launch delay and cost, including human error, hardware issues that remain undetected until testing, excessive optimism, and the fact that many facets of the cutting-edge telescope tread entirely new ground.
Despite the issues with the project, the board unanimously agreed that production and testing of the JWST should continue, due in part to the compelling scientific discoveries that the telescope is capable of making, and the national importance of the project.
To help reduce the risk posed by the aforementioned factors, the board has issued 32 recommendations designed to maximize the chances of mission success. According to NASA, many of these recommendations – which deal with elements such as procedure and personnel training – are already being implemented.
During the teleconference, NASA announced that it had an 80 percent confidence regarding their chances of meeting the new launch date. Regarding the effect that the delay would have on procuring the Ariane 5 launch vehicle for the JWST, Thomas Zurbuchen, associate administrator of NASA's Science Mission Directorate, stated, "We are assured by our ESA colleagues that the launch vehicle as foreseen will be available."
NASA also announced that in order to accommodate the revised launch date, and implement the recommendations of the IRB, that the estimated development cost of the JWST had risen from $8 billion to $8.8 billion. The total lifecycle cost of the project which takes into account development, testing, and five years of operational costs once in orbit, has risen to $9.66 billion.
The JWST had previously been allotted an $8 billion spending cap, and now that this cap is broken, NASA will need to seek further congressional approval to account for the new estimate.
Source: NASA