Spaceflight Insider

James Webb Space Telescope’s woes continue

A NASA technician prepares part of the James Webb Space Telescope for cryogenic testing of its primary mirror segments. Image Credit: David Higginbotham / Emmett Given / NASA / MSFC

Within weeks after launch it was clear something had gone drastically wrong with the Hubble Space Telescope. While the issue, a slightly misshapen mirror, was quickly identified as the culprit, it would take another three years before another shuttle mission as sent to finally adjust the error on orbit. Engineers at NASA constructing Hubble’s replacement are under considerable pressure to ensure everything goes smoothly with the flight of its successor, the James Webb Space Telescope (JWST). However, the infrared telescope, already nearly a decade behind schedule and eight times the initial cost – already has an uneasy legacy. Things appear however, to not be improving for spacecraft.

Designed to follow in Hubble’s footsteps, JWST has been in development since the mid 1990s. It is currently set to be launched in 2018 atop an Ariane 5 rocket from Kourou, French Guiana. At a current cost of some $8.8 billion, the telescope has, for more than a decade, been among NASA’s most expensive and troubled science missions. Yet consistent cost overruns and, more recently, a number of technical issues have prompted some in the government to go as far as to call for its cancellation (not the first time that the telescope has been under the axe).

JWST was under consideration to be cancelled by the U.S. Congress in 2011 after approximately $3 billion had already been spent. Luckily, some 75 percent of the JWST’s hardware had been produced or was undergoing testing at that time. In November of that year, Congress allowed the program to move ahead – but capped additional spending on it at $8 billion.

Of the four scientific instruments to be housed in Webb’s Integrated Science Instrument Module (ISIM), at least two have suffered setbacks in the last three years.

A full-scale mockup of the James Webb Space Telescope as envisioned by NASA. Image credit: NASA

A full-scale mockup of the James Webb Space Telescope as envisioned by NASA. Image credit: NASA

In 2011, the European Space Agency’s (ESA) near-infrared spectrograph (NIRSpec) unit appeared to be damaged with several cracks, prompting a lengthy rebuild during which shutter problems continued to delay the team. The faulty shutter is expected to be swapped out in 2015 between rounds of testing.

In that same time NASA has also been wrestling with malfunctioning cryogenic coolant valves for the mid-infrared instrument (MIRI). The coolant system is required to ensure the continuous and safe operation of ISIM instruments in the wildly changing temperature fluctuations of deep space. A poor fitting valve was found leaking, and while NASA is testing replacements the Space Agency is also considering whether to move forward with alternative valves procured from a second subcontractor.

As noted in a recent article appearing on Space News, in March of 2013 deputy program manager for JWST Eric Smith acknowledged, “the cryo-cooler has been a problem for many years.” Nevertheless, the coolant system delay appears to have had no impact on the telescope’s ultimate launch deadline. Whether that remains the case will hinge on how well the valve components sustain vacuum tests set to begin this summer.

The James Webb Space Telescope, was named after NASA’s second administrator and is intended to be a large infrared telescope with a primary mirror almost twenty feet in diameter. It is hoped that the telescope’s data will be used by thousands of astronomers and universities from points across the globe to study everything from events just after the big bang to the search for Earth-like planets circling distant stars. The telescope is currently on schedule and within its adjusted budget.

 

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Since 2011 Joshua Tallis has served as the manager for research and analysis at an intelligence and security services provider in Washington, DC. Josh has co-authored several articles in the Journal of Counterterrorism and Homeland Security International with colleagues from the defense community. Previous work experience includes internships at the U.S. Congress and the Foundation for Defense of Democracies. Josh is also a PhD student in International Relations at the University of St Andrews' Centre for the Study of Terrorism and Political Violence. He is a Summa Cum Laude, Phi Beta Kappa and Special Honors graduate of The George Washington University where he received a BA in Middle East Studies from the Elliott School of International Affairs.

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