The Spitzer Space Telescope (SST) was the largest and most sophisticated infrared space telescope ever launched. Like the Infrared Space Observatory (ISO), SST is designed for targeted observations, rather than all-sky surveys. It is, however, much larger than ISO, and it has much better image-taking and spectroscopic resolution and sensitivity, as well. The Spitzer Telescope was launched on August 25, 2003, and its first images were released to the public on December 18 of that year.