The 40 cm diameter WISE telescope. The WISE telescope is an all aluminum optical system that will produce images of the sky with 2.75 arcsec resolution in four infrared spectral bands. Here the lead optical test engineer attaches the back-end imager optics to the afocal. This entire telescope will be mounted inside the WISE cryostat and cooled to about 17K. The WISE telescope was developed by L3 Communications-SSG. (Photo: NASA/JPL-Caltech/SSG)