Webb Update

Massimo Stiavelli, mstiavel@stsci.edu

Developing the James Webb Space Telescope is now in full swing. Components representing 14% of the mass of the observatory have been fabricated, and other parts for 47% of the mass are under construction. The remaining 39% of the mass will be completed over the next two years. Important components of the observatory—and, indeed, the mission itself—recently passed major reviews. A test of figuring primary-mirror segments was a success. With these milestones accomplished, the phase of designing and analyzing Webb winds down, and the era of integrating and testing ramps up.

In February 2010, the demonstration model of the Near Infrared Spectrograph was delivered to the Goddard Space Flight Center to begin testing. The large clean room used for work on Hubble servicing missions is now being used for Webb. NASA has installed a “Webb cam” in the clean room to provide continuous coverage of the assembly of the Webb instruments and telescope (view it here).

Passed Reviews

In October 2009, Webb’s Optical Telescope Element (OTE) passed its critical design review (CDR). The OTE comprises the primary, secondary, tertiary, and fine steering mirrors.

In January 2010, the Webb sunshield passed its CDR. The sunshield is a critical component of the observatory, as it enables the telescope optics and instruments to radiatively cool down to 40 K. At launch, the sunshield will be folded, but will deploy to its full tennis-court size en route to L2. NASA had delayed manufacturing the sunshield so the design team could work through several prototypes before selecting the design that offered the greatest deployment reliability and protection during integration and launch.