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Webb is optimized for seeing the sky in infrared light, and its instruments must be kept cool. Thus, the telescope will sport a giant sunshade the size of a tennis court, which will unfold after Webb has reached its final destination, a gravitationalally stable place at about 930,000 miles (1.5 million kilometers ) of the earth.
The road to this destination has been quite bumpy to this day. Webb is a very complex observatory that has proven difficult to build and test for the main contractor Northrop Grumman, as evidenced by the repeated delays.
Until recently, NASA was aiming for a launch in October 2018. In September of last year, however, NASA announced that shipboard integration issues had delayed launch until the spring of 2019. Then, last March, the agency postponed the scheduled date of takeoff until May 2020. More time was needed to test Webb complex systems and deal with setbacks, such as small tears in the sun visor, NASA officials said at the time.
The agency also set up an Independent Review Committee (IRB) in March to monitor the progress of the observatory and develop recommendations. The IRB reported to NASA on May 31, and the agency completed its response to this report on June 26. (You can read NASA's report and response here.)
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traced back the 29 month delay (from a targeted launch date of October 2018 to March 2021) to five factors: human error, "nested problems", excessive optimism, complexity of systems and lack of experience in key areas, such as the development of sunshades. .
IRB President Tom Young outlined some of the most significant human errors at today's news conference. Technicians used the wrong solvent to clean the propulsion valves, used improper wiring that caused excessive strain on the transducers, and improperly secured the sunshade mountings before a key test, he said.
"All the simple repairs that have not been implemented have resulted in a delay of about a year and a half, at a cost of about $ 600 million," Young said. , former director of NASA's Goddard Space Flight Center in Greenbelt, Maryland. President and Chief Operating Officer of Martin Marietta Aerospace Corporation, which merged with Lockheed Corporation in 1995, forming Lockheed Martin.
The IRB report played a key role in NASA's latest plan for Webb, agency officials said. Indeed, the review panel made 32 separate recommendations for the development of the observatory, of which 30 are fully in agreement with NASA, said Zurbuchen. The agency still considers the other two, he added.
Basically, the IRB did not recommend pulling the plug on the telescope.
"With all the factors I've discussed, the IRB believes that JWST should continue, because of convincing science, and because of the national importance of JWST," Young said.
The increase in mission development costs from $ 8 billion to $ 8.8 billion could, however, complicate this vision. The old number was a limit imposed by Congress, which means that Webb needs another approval from Capitol Hill to continue.
"We are submitting our final violation report to Congress this week," NASA Associate Administrator Steve Jurczyk told the press conference today. "And then, it is true that the Congress will have to reauthorize Webb through this next cycle of credits."
Originally published on Space.com .
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