
"Extending the launch window provided the project up to 4 months of schedule reserve. However, shortly after requesting the new launch window in September 2017, the project determined that several months of schedule reserve would be needed to address lessons learned from the initial folding and deployment of the observatory's sunshield. Given remaining integration and test work ahead--the phase in development where problems are most likely to be found and schedules tend to slip--coupled with only 1.5 months of schedule reserves remaining to the end of the launch window, additional launch delays are likely. The project's Standing Review Board will conduct an independent review of JWST's schedule status in early 2018 to determine if the June 2019 launch window can be met. JWST will also have limited cost reserves to address future challenges, such as further launch delays, and is at risk of breaching its $8 billion cost cap for formulation and development set by Congress in 2011. For several years, the prime contractor has overestimated workforce reductions, and technical challenges have prevented these planned reductions, necessitating the use of cost reserves. Program officials said that existing program resources will accommodate the new launch window--provided remaining integration and testing proceeds as planned without any long delays. However, JWST is still resolving technical challenges and work continues to take longer than planned to complete. As a result, the project is at risk of exceeding its $8 billion formulation and development cost cap."
Keith's 1 March update: NASA PAO just sent me this statement to post: "After the successful test performance of the James Webb Space Telescope science payload last year, and the delivery of that payload to Northrop Grumman Aerospace Systems, NASA looks forward to the mission's final integration and test phase now that the two major observatory elements (science payload and spacecraft with sunshield) are together under one roof for the first time. As we enter this critical and challenging period, the Webb project is carefully reviewing its plans for the remaining tasks. The mission's Standing Review Board will begin an independent assessment of the project plans in mid-March with an expected report out in early April."