Workers add another base plate segment to the shrouded Space Infrared Telescope Facility. The base plate is being added for the canister. 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. SIRTF is currently scheduled for launch aboard a Delta II rocket from Launch Complex 17-B, Cape Canaveral Air Force Station.