The Space InfraRed Telescope Facility (SIRTF) is the fourth and final element in NASA's family of Great Observatories and represents an important scientific and technical bridge to NASA's Astronomical Search for Origins program. The Observatory carries an 85-centimeter cryogenic telescope and three cryogenically cooled science instruments capable of performing imaging and spectroscopy in the 3.6 to 160 micron range. In January 2003 SIRTF will be launched on a Delta 7920H from NASA's Kennedy Space Center into an Earth-trailing heliocentric orbit. While the SIRTF cryogenic lifetime requirement is 2.5 years, current estimates indicate that achieving a goal of a 5-year cryogenic mission is possible.

For the past two and a half years, I have worked on the InfraRed Array Camera (IRAC), one of three science instruments on board. I will give an overview of SIRTF's instrumentation and discuss some of the science planned for the first two years of operation.