KENNEDY SPACE CENTER, FLA. - Workers on an upper level of the launch tower on Launch Complex 17-B, Cape Canaveral Air Force Station, watch as the Boeing Delta II second stage is lifted. It will be mated with the first stage, completing the erection of the launch vehicle for NASA's Space Infrared Telescope Facility. SIRTF will obtain images and spectra by detecting the infrared energy, or heat, radiated by objects in space. Most of this infrared radiation is blocked by the Earth's atmosphere and cannot be observed from the ground. Consisting of an 0.85-meter telescope and three cryogenically cooled science instruments, SIRTF is one of NASA's largest infrared telescopes to be launched.