Spitzer will slowly drift away from the Earth at the rate of about 16,000,000 km per year. The spacecraft is launched into a solar, Earth-trailing orbit, far enough away from the planet so Earth's radiation does not interfere with the cooling of the telescope. Key achievements: Launched into solar orbit on August 25, 2003, Spitzer was initially scheduled for a minimum 2.5-year primary mission. Spitzer Space Telescope Workers at the Kennedy Space Center at Cape Canaveral, Florida, inspecting the Spitzer Space Telescope on May 2, 2003. NASA The Spitzer observatory was launched on August 25, 2003, by a Delta II rocket .

Now it retires. Artist's concept of Spitzer Assembly of telescope Stephan's Quintet Spitzer Space Telescope Overview: The Spitzer Space Telescope, formerly known as the Space Infrared Telescope Facility, is an infrared telescope that studies the early universe, young galaxies and forming stars, and is used to detect dust disks around stars, considered an important signpost of planetary formation. The Spitzer Space Telescope is the final mission in NASA's Great Observatories Program - a family of four space-based observatories, each observing the universe in a different kind of light. By using Nature to assist in cooling the Observatory, Spitzer can carry much less liquid helium cryogen than it would need in an Earth orbit.

The SST Observatory carries an 85-cm cryogenic telescope … The Spitzer redesign also managed to cut costs by placing the observatory into an Earth-trailing orbit. This means that it will not circle around the Earth. This is because the telescope has a very particular orbit, trailing about 158 million miles behind the Earth to keep it away from interfering heat.

This database table contains the Spitzer Space Telescope (SST) log of executed and scheduled observations, and is updated on a weekly basis. NASA’s Kepler space telescope, famous for finding thousands of exoplanets – planets outside our solar system -- also settled in an Earth-trailing orbit six years after Spitzer. The James Webb Space Telescope will not be in orbit around the Earth, like the Hubble Space Telescope is - it will actually orbit the Sun, 1.5 million kilometers (1 million miles) away from the Earth at what is called the second Lagrange point or L2. The Spitzer Space Telescope (formally known as SIRTF) was successfully launched on August 25, 2003, and has completed its initial in-orbit checkout and science validation and calibration period. As NASA prepares to bid farewell to the Spitzer Space Telescope on Thursday, take a look back at some of the coolest things it’s shown us in 16 years of space-based infrared astronomy. Spitzer imaged the coiled galaxy NGC 1097 during its cold mission.

A Solar Orbit . Drifting in a unique Earth-trailing orbit around the Sun, Spitzer sees an optically invisible universe dominated by dust and stars. The telescope’s dust cover was ejected Aug. 29 and its aperture door opened the next day. NASA’s Kepler space telescope, famous for finding thousands of exoplanets – planets outside our solar system -- also settled in an Earth-trailing orbit six years after Spitzer. The end of Spitzer leaves NASA without a space-based infrared telescope at least until the launch of JWST, followed by the Wide-Field Infrared Survey Telescope in the mid-2020s. Instead, it will trail behind the Earth as the Earth orbits around the Sun. The Spitzer Space Telescope was launched into an innovative Earth-trailing solar orbit. In January 2020, NASA’s Spitzer Space Telescope mission ended, bringing to a close a pivotal chapter in astronomy. Instead of orbiting Earth itself, the observatory trails behind Earth as it orbits the Sun â and drifts away from us at about 1/10th of one astronomical unit per year.

Spitzer 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. Ever since NASA launched Spitzer Space Telescope in 2003, it's sent stunning infrared images and new insight into the wonders of our universe. In this orbit, at 0.996 × 1.019 AU, Earth doesn’t hinder observation of potential targets. On this date, NASA’s Spitzer Space Telescope will send us its final observations, finishing a remarkable,16-year exploration of the universe at infrared wavelengths. But the space telescope has lasted far beyond its expected lifetime. Spitzer is designed to detect infrared radiation, which is primarily heat radiation.

More: The infrared universe seen by NASA's Spitzer Space Telescope Spitzer launched in 2003, designed for a 2.5-year mission. Spitzer imaged the coiled galaxy NGC 1097 during its cold mission.

NASA's Spitzer Space Telescope was launched on August 25, 2003 from Florida's Cape Canaveral Air Force Base.

The mission’s observations led to many discoveries, including soccer-ball-shaped molecules in space called buckyballs; the largest ring around Saturn; and infant galaxies at the dawn …

The drifting heliocentric orbit places Spitzer in "deep space," where the temperature of the telescope without any active cooling is about 30 to 40K.