The First Major Reviews And A Financial Shock
As is typical in major NASA developments, the element, systems and subsystems teams proceeded ahead of the overall mission reviews. All the science instrument teams, except for the NIRSpec team, passed their preliminary design reviews in 2005 and began development of their long lead items and engineering models. In May, Brush Wellman had delivered all 20 Be segments to Axsys for light-weighting.
NASA administrator signed off on the use of the Ariane 5 on February 2005. Despite this good news, which formalized the contributions of ESA to the mission, the Project discovered both technical and financial difficulties that forced another schedule and technical replan. With the better defined observatory and system designs, the overall observatory mass estimate had become too high for the phase of the project (before PDR and Critical Design Review – CDR). To reduce mass, particularly in the area of the ISIM and optics, the Project and MIRI changed from a cryostat to a cryocooler. Fortunately, the cryocooler technology development had progressed to the point where this posed little risk to the MIRI and observatory design. NASA and CSA agreed to reduce and simplify the Tunable Filter Imager.
Financial problems were more difficult to address. NASA received new estimates on the cost-to-complete from Northrop Grumman and the NASA ISIM team (science instruments and their support). Along with the reserves required to cover unknown difficulties in development, the estimated overall development cost almost doubled, from about 2B to 3.5B. This led to a major re-planning exercise and the chartering of the Science Assessment Team. Their report prioritized the scientific capabilities of Webb and endorsed relaxation of several driving performance requirements. The SAT also recommended that the I&T tests be simplified to take advantage of the adjustable optics.
Following a number of reviews and the recommendations of the SAT and Independent Program Assessment Office (IPAO), the JWST Project re-baselined the project for a launch date no earlier than June 2013. The Project team identified significant savings and risk reductions. Using a "cup-up" configuration for the final optical testing of JWST at the Johnson Space Center would save more than $100M and significantly reduce the costs of additional testing, if required. The SAT's recommendation to relax the optical requirements at 1 micron also significantly reduced the cost of additional cryo-polishing cycles for the Be primary mirror segments (the individual segment quality was relaxed). While many areas in the program had slowed down due to lower funding levels, the Project maintained schedule on the manufacture of mirror segments and in reaching the appropriate flight qualification of new technologies.