NASA tweeted "Our @NASAWebb Space Telescope is now undergoing final integration & test phases that will require more time to ensure a successful mission". This infrared space telescope will revolutionize our ability to detect and characterize exoplanets, study the very early universe, and peer deep into the dusty clouds where stars are born.
Back in 2011, politicians on Capitol Hill said the observatory should not take more than $8bn to build and $800m to operate over five years in orbit.
Launching a project of this size and scope will be an unbelievable achievement, but it is not without its challenges. Robert Lightfoot, NASA's acting administrator stated, "The project has achieved numerous successful milestones, and 100 percent of the observatory's flight hardware is now complete".
Testing is extremely important for any observatory, but this one perhaps more so than previous projects. That means that NASA would need to ask lawmakers to provide more money for further testing and completion of the space telescope.
Testing the hardware on the observatory's telescope element and spacecraft element demonstrate that these systems individually meet their requirements.
But even thinking about what might happen once the JWST reaches orbit might be getting ahead of ourselves.
The telescope uses huge, gold-coated mirrors necessary to observe distant objects, and it comes complete with a giant tennis court-sized sunshield which should help keep the spacecraft cool as it gathers data on humanity's behalf. Before being officially aproved, the Next Generation Space Telescope, as it was known back then, was thought likely to cost from $1bn to $3.5bn. Since the project began in 1996, its scope has widened and its budget has ballooned from $0.5 billion to $8.8 billion. A review board recently determined, however, that more time is needed to test and integrate the components together.
It was during the testing of the spacecraft element that several technical issues arose.
Associate administrator of NASA's Science Mission Directorate, Thomas Zurbuchen stated that, "Considering the investment NASA and our worldwide partners have made, we want to proceed systematically through these last tests, with the additional time necessary, to be ready for a May 2020 launch".
Where does the project stand now?
This is a pivotal year for Webb when the 6.5-meter telescope and science payload element will be joined with the spacecraft element to form the complete observatory. Furthermore, the telescope will be located 1.5 million kilometers from the Earth, so it will be impossible for astronauts to go there to fix the machine in case of a problem as was the case with the Hubble Space Telescope, orbiting at only a few hundred kilometers.
NASA is establishing an external Independent Review Board (IRB), chaired by Thomas Young, a highly respected NASA and industry veteran who is often called on to chair advisory committees and analyze organizational and technical issues. During testing of the sunshield's folding process and subsequent deployment sequence, it was found that tears developed and the sunshield's tensioning cables had to be redesigned, as the original design left too much slack. NASA says it will take both recommendations and findings from both boards, ultimately giving its own assessment to Congress later on this summer.