Can NASA save money by scaling JWST down to a 4-m?
No. Blanks for the eighteen primary mirror segments for JWST’s 6.6-m mirror have already been manufactured and are in various stages of polishing. Changing to a smaller diameter mirror now would require a major mission redesign with a concomitant delay, yielding a large net cost increase. Even simply removing several mirror segments from the current design would create problems with stray light in the optics and the balance of mass in the spacecraft. • Who paid for the full-scale JWST model? The full-scale model was built and is supported entirely with Northrop Grumman internal funds. JWST’s Instruments • What are the capabilities of NIRCam? The Near-Infrared Camera (NIRCam) provides filter imaging in the 0.6 to 5.0 micron range. With a dichroic splitting the light at 2.4 microns, NIRCam provides simultaneous imaging of a 2.2 by 4.4 arcmin2 field of view in two filters. The short wavelength channel contains eight 2048 by 2048 pixel detectors with 32 milliarcsec pixels, and the long wav
