The Delta II rocket on Launch Complex 17-B, Cape Canaveral Air Force Station, waits for additional solid rocket boosters to be mated. The Delta II will launch the Space Infrared Telescope Facility. The second stage will later be hoisted atop the first stage. 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.