1. The Universe in the Infrared What is the Spitzer Space Telescope, and how does it work? Funded by NASA’s Spitzer Science Center Images courtesy NASA/JPL - Caltech

2. Pilachowski / August 2005 The Universe in the Infrared Slide 2 Outline  NASA’s Great Observatories  Introducing Spitzer  Spitzer’s Launch  Orbit  Naming Spitzer  The Telescope  Instruments  Future IR Telescopes

3. Pilachowski / August 2005 The Universe in the Infrared Slide 3 NASA’s Great Observatories Spitzer is the final spacecraft in NASA's Great Observatories program HST 1990 Compton GRO 1991 Chandra 1999

4. Pilachowski / August 2005 The Universe in the Infrared Slide 4 Introducing Spitzer The Spitzer Space Telescope is a cryogenically cooled, infrared observatory in space. Spitzer can study objects ranging from our Solar System to the distant reaches of the Universe.

5. Pilachowski / August 2005 The Universe in the Infrared Slide 5 Launch Launched from KSC on 25 August 2003 Lifetime: 2.5 years (minimum); 5+ years (goal)

6. Pilachowski / August 2005 The Universe in the Infrared Slide 6 Heliocentric Orbit Most space telescopes orbit the Earth Spitzer orbits the Sun - trailing the Earth as it moves around the Sun Spitzer is receding from Earth at 9.3 million miles (15 million kilometers) per year Spitzer now trails the Earth in its orbit by about 20 million miles (~ 32 million kilometers) By 2008, Spitzer will be about 56 million miles or 90 million kilometers away

7. Pilachowski / August 2005 The Universe in the Infrared Slide 7 Named for Lyman Spitzer  Lyman Spitzer was the driving force behind HST  Founded the study of the interstellar medium  Studied interstellar dust and star formation

8. Pilachowski / August 2005 The Universe in the Infrared Slide 8 Introducing the Telescope

9. Pilachowski / August 2005 The Universe in the Infrared Slide 9 Spitzer Specs Mirror: 85 cm (33.5”) diameter lightweight beryllium f/12 curvature Weight: Telescope: 851.5 kg He cryogen: 50.4 kg N propellent: 15.6 kg

10. Pilachowski / August 2005 The Universe in the Infrared Slide 10 Keeping Spitzer Cold Telescope operates at 5.5 K Why? - Spitzer is itself a black body radiator, and must be colder than the astronomical sources it detects How? –Heliocentric orbit –Solar shield/solar cells –Outer shell insulates and cools the telescope

11. Pilachowski / August 2005 The Universe in the Infrared Slide 11 Keeping Spitzer’s Instruments Even Colder A tank of liquid helium is used to keep Spitzer’s instruments and detectors at 1.5 K

12. Pilachowski / August 2005 The Universe in the Infrared Slide 12 Spitzer’s Instruments IRAC – InfraRed Array Camera –images at 3.6, 4.5, 5.8, and 8  m IRS – InfraRed Spectrograph –mid-IR spectroscopy MIPS – Multiband Imaging Photometer for Spitzer –images at 24, 70, and 160  m IRS MIPS IRAC

13. Pilachowski / August 2005 The Universe in the Infrared Slide 13 InfraRed Array Camera (IRAC) Built at the Smithsonian Astrophysical Observatory Simultaneous images in four IR passbands

14. Pilachowski / August 2005 The Universe in the Infrared Slide 14 InfraRed Spectrometer Built at Cornell University Spectroscopy in the mid-IR

15. Pilachowski / August 2005 The Universe in the Infrared Slide 15 Multiband Imaging Photometer for Spitzer (MIPS) Three detector arrays –128x128 pixel Si:As for 24 mm –32x32 pixel Ge:Ga for 70 mm –2x20 pixel Ge:Ga for 160 mm Built at the University of Arizona

16. Pilachowski / August 2005 The Universe in the Infrared Slide 16 Spitzer Focal Plane Spitzer instruments are arranged in fixed locations on the Spitzer focal plane The telescope is rotated to move a particular science target to the right position for the instrument to be used Other instruments record data for “serendipitous” fields

17. Pilachowski / August 2005 The Universe in the Infrared Slide 17 Spitzer Operations www.spitzer.caltech.edu/about/now.shtml What Is Spitzer Doing Now?

18. Pilachowski / August 2005 The Universe in the Infrared Slide 18 Future Infrared Satellites 2007: Herschel Space Observatory - a European Space Agency infrared- submillimeter mission planned for 2007 to study galaxy formation, interstellar matter, star formation and the atmospheres of comets and planets. 2007: Planck Surveyor - European Space Agency far infrared- submillimeter mission planned for 2007 to study Cosmic Background Radiation. 2010: The James Webb Space Telescope, planned for launch in about 2011, is a visible/infrared space mission to study the early universe and the formation of galaxies, stars and planets.