View source for Spitzer Space Telescope

{{short description|Infrared space telescope (2003–2020)}}
{{Use dmy dates|date=September 2019}}
{{Infobox spaceflight
| name                  = Spitzer Space Telescope
| names_list            = Space Infrared Telescope Facility

| image                 = Spitzer space telescope.jpg
| image_caption         = An artist rendering of the Spitzer Space Telescope
| image_size            = 300px

| mission_type          = Infrared [[space telescope]]
| operator              = [[NASA]]{{\}}[[Jet Propulsion Laboratory|JPL]]{{\}}[[California Institute of Technology|Caltech]]
| COSPAR_ID             = 2003-038A
| SATCAT                = 27871
| website               = [http://www.spitzer.caltech.edu/ www.spitzer.caltech.edu]
| mission_duration      = Planned: 2.5 to 5+ years<ref name=nasa20070422 /> <br /> Primary mission: {{time interval|25 August 2003 05:35:39|15 May 2009|show=ymd|sep=,}} <br /> Final: {{time interval|25 August 2003 05:35:39|30 January 2020|show=ymd|sep=,}}

| manufacturer          = [[Lockheed Missiles and Space Company|Lockheed]]<br/>[[Ball Aerospace & Technologies|Ball Aerospace]]
| launch_mass           = {{convert|950|kg|lb|0|abbr=on}}<ref name="nasa20070422">{{Cite web |date=2008 |title=About Spitzer: Fast Facts |url=https://www.spitzer.caltech.edu/mission/fast-facts |url-status=live |archive-url=https://web.archive.org/web/20231003134017/https://www.spitzer.caltech.edu/mission/fast-facts |archive-date=3 October 2023 |access-date=22 April 2007 |publisher=[[Jet Propulsion Laboratory]] }}</ref>
| dry_mass              = {{convert|884|kg|lb|0|abbr=on}}
| payload_mass          = {{convert|851.5|kg|lb|abbr=on}}<ref name=nasa20070422/>
| dimensions            = <!--body dimensions and solar array span-->
| power                 = 427 W<ref name="jpl-solarpanel">{{Cite web |title=The Solar Panel Assembly |url=https://www.spitzer.caltech.edu/mission/the-solar-panel-assembly/ |url-status=live |archive-url=https://web.archive.org/web/20230928174914/https://www.spitzer.caltech.edu/mission/the-solar-panel-assembly |archive-date=28 September 2023 |publisher=[[Jet Propulsion Laboratory]] }}</ref>

| launch_date           = {{start-date|25 August 2003, 05:35:39}}&nbsp;[[UTC]]<ref name="sfnow20030825"/>
| launch_rocket         = [[Delta II]] 7920H<ref name="nssdc-orbit">{{Cite web |title=Spitzer Space Telescope: Launch/Orbital Information |url=https://nssdc.gsfc.nasa.gov/nmc/spacecraft/display.action?id=2003-038A |url-status=live |archive-url=https://web.archive.org/web/20230924234655/https://nssdc.gsfc.nasa.gov/nmc/spacecraft/display.action?id=2003-038A |archive-date=24 September 2023 |access-date=26 April 2015 |publisher=[[National Space Science Data Center]] |id=2003-038A }}</ref>
| launch_site           = [[Cape Canaveral Air Force Station|Cape Canaveral]] [[Cape Canaveral Air Force Station Space Launch Complex 17|SLC-17B]]
| entered_service       = 18 December 2003

| disposal_type         = Deactivated in Earth-trailing orbit
| deactivated           = 30 January 2020<ref name='SciAm 2019'/>
| destroyed             = <!--when craft was destroyed (if other than by re-entry)-->
| last_contact          = <!--when last signal received if not decommissioned-->

| orbit_reference       = [[Heliocentric orbit|Heliocentric]]<ref name=nasa20070422/>
| orbit_regime          = Earth-trailing<ref name=nasa20070422/>
| orbit_eccentricity    = 0.011<ref name="JPL-Horizons">{{cite web |url=http://ssd.jpl.nasa.gov/horizons.cgi |title=HORIZONS Web-Interface |publisher=[[Jet Propulsion Laboratory]] |access-date=16 March 2017}}</ref>
| orbit_periapsis       = 1.003 [[astronomical unit|AU]]<ref name="JPL-Horizons"/>
| orbit_apoapsis        = 1.026 AU<ref name="JPL-Horizons"/>
| orbit_inclination     = 1.13°<ref name="JPL-Horizons"/>
| orbit_period          = 373.2 days<ref name="JPL-Horizons"/>
| orbit_epoch           = 16 March 2017 00:00:00
| apsis                 = helion

| telescope_type        = [[Ritchey–Chrétien telescope|Ritchey–Chrétien]]<ref name="spitscope">{{Cite web |title=About Spitzer: Spitzer's Telescope |url=https://www.spitzer.caltech.edu/mission/the-telescope |url-status=live |archive-url=https://web.archive.org/web/20231003125624/https://www.spitzer.caltech.edu/mission/the-telescope |archive-date=3 October 2023 |access-date=22 April 2007 |publisher=[[Jet Propulsion Laboratory]] }}</ref>
| telescope_diameter    = {{convert|0.85|m|ft|abbr=on}}<ref name=nasa20070422/>
| telescope_focal_length= {{convert|10.2|m|ft|abbr=on}}
| telescope_area        = <!--collecting area-->
| telescope_wavelength  = [[infrared]], 3.6–160&nbsp;[[micrometre|μm]]<ref name="handbook3.2">{{Cite web |last1=Van Dyk |first1=Schuyler |last2=Werner |first2=Michael |last3=Silbermann |first3=Nancy |date=March 2013 |orig-date=2010 |title=3.2: Observatory Description |url=https://irsa.ipac.caltech.edu/data/SPITZER/docs/spitzermission/missionoverview/spitzertelescopehandbook/7/ |url-status=live |archive-url=https://web.archive.org/web/20230410134335/https://irsa.ipac.caltech.edu/data/SPITZER/docs/spitzermission/missionoverview/spitzertelescopehandbook/7/ |archive-date=10 April 2023 |access-date=18 October 2015 |publisher=[[Infrared Science Archive]] |work=Spitzer Telescope Handbook }}</ref>
| instruments_list      = {{Infobox spaceflight/Instruments
   | acronym1 = IRAC  | name1 = Infrared Array Camera
   | acronym2 = IRS   | name2 = Infrared Spectrograph
   | acronym3 = MIPS  | name3 = Multiband Imaging Photometer for Spitzer
  }}

| programme             = '''[[Great Observatories program|NASA Great Observatories]]'''
| previous_mission      = [[Chandra X-ray Observatory|Chandra]]
| insignia              = NASA-SpitzerTelescope-Logo.svg
}}
[[File:HUDF-JD2.jpg|thumb|right|Infrared observations can see objects hidden in visible light, such as [[HUDF-JD2]], shown. This shows how the Spitzer IRAC camera was able to see beyond the wavelengths of Hubble's instruments.]]

The '''Spitzer Space Telescope''', formerly the '''Space Infrared Telescope Facility''' ('''SIRTF'''), was an [[infrared]] [[space telescope]] launched in 2003, that was deactivated when operations ended on 30 January 2020.<ref name='SciAm 2019'/><ref name="NYT-20200130">{{Cite news |last=Mann |first=Adam |date=30 January 2020 |title=NASA's Spitzer Space Telescope Ends 16-Year Mission of Discovery |url=https://www.nytimes.com/2020/01/30/science/nasa-spitzer-space-telescope.html |url-access=subscription |url-status=live |archive-url=https://web.archive.org/web/20230802184410/https://www.nytimes.com/2020/01/30/science/nasa-spitzer-space-telescope.html |archive-date=2 August 2023 |access-date=4 February 2020 |work=[[The New York Times]] }}</ref> Spitzer was the third space telescope dedicated to infrared astronomy, following [[IRAS]] (1983) and [[Infrared Space Observatory|ISO]] (1995–1998). It was the first spacecraft to use an [[Earth-trailing orbit]], later used by the [[Kepler space telescope|Kepler]] planet-finder.

The planned mission period was to be 2.5 years with a pre-launch expectation that the mission could extend to five or slightly more years until the onboard [[liquid helium]] supply was exhausted. This occurred on 15 May 2009.<ref name="nasa20090515">{{Cite press release |last=Clavin |first=Whitney |date=15 May 2009 |title=NASA's Spitzer Begins Warm Mission |url=https://www.spitzer.caltech.edu/news/ssc2009-12-nasas-spitzer-begins-warm-mission |url-status=live |archive-url=https://web.archive.org/web/20240103222937/https://www.spitzer.caltech.edu/news/ssc2009-12-nasas-spitzer-begins-warm-mission |archive-date=3 January 2024 |access-date=26 April 2015 |publisher=[[Jet Propulsion Laboratory]] |id=ssc2009-12, jpl2009-086 |location=Pasadena, California }}</ref> Without liquid helium to cool the telescope to the very low temperatures needed to operate, most of the instruments were no longer usable. However, the two shortest-wavelength modules of the [[#Instruments|IRAC]] camera continued to operate with the same sensitivity as before the helium was exhausted, and continued to be used into early 2020 in the '''Spitzer Warm Mission'''.<ref name="spitzer-warm-prospect">{{Cite conference |last1=Stauffer |first1=John R. |last2=Mannings |first2=Vincent |last3=Levine |first3=Deborah |last4=Chary |first4=Ranga Ram |last5=Wilson |first5=Gillian |last6=Lacy |first6=Mark |last7=Grillmair |first7=Carl |last8=Carey |first8=Sean |last9=Stolovy |first9=Susan |date=August 2007 |title=The Spitzer Warm Mission Science Prospects |url=https://irsa.ipac.caltech.edu/data/SPITZER/docs/spitzermission/reportsandproceedings/meetings/warm/wp/003stauffer.pdf |conference=Spitzer Warm Mission Workshop |series=[[AIP Conference Proceedings]] |publisher=[[American Institute of Physics]] |volume=943 |pages=43–66 |bibcode=2007AIPC..943...43S |doi=10.1063/1.2806787 |archive-url=https://web.archive.org/web/20231227032410/https://irsa.ipac.caltech.edu/data/SPITZER/docs/spitzermission/reportsandproceedings/meetings/warm/wp/003stauffer.pdf |archive-date=27 December 2023 |url-status=live }}</ref><ref name="cycle6">{{Cite web |title=Cycle-6 Warm Mission |url=http://sohelp2.ipac.caltech.edu/support/index.php?_m=knowledgebase&_a=view&parentcategoryid=8&nav=0 |url-status=dead |archive-url=https://web.archive.org/web/20100704070443/http://sohelp2.ipac.caltech.edu/support/index.php?_m=knowledgebase&_a=view&parentcategoryid=8&nav=0 |archive-date=4 July 2010 |access-date=16 September 2009 |website=Spitzer Science Center |publisher=[[Jet Propulsion Laboratory]] }}</ref>

During the warm mission, the two short wavelength channels of IRAC operated at 28.7 K and were predicted to experience little to no degradation at this temperature compared to the nominal mission. The Spitzer data, from both the primary and warm phases, are archived at the [[Infrared Science Archive]] (IRSA).

In keeping with NASA tradition, the telescope was renamed after its successful demonstration of operation, on 18 December 2003. Unlike most [[telescope]]s that are named by a board of scientists, typically after famous deceased astronomers, the new name for SIRTF was obtained from a contest open to the general public.
The contest led to the telescope being named in honor of astronomer [[Lyman Spitzer]], who had promoted the concept of space telescopes in the 1940s.<ref name="spitzer_bio">{{Cite web |last=Applewhite |first=Denise |date=11 March 2004 |title=Lyman Spitzer Jr. |url=https://www.spitzer.caltech.edu/mission/lyman-spitzer-jr |url-status=live |archive-url=https://web.archive.org/web/20240121093351/https://www.spitzer.caltech.edu/mission/lyman-spitzer-jr |archive-date=21 January 2024 |access-date=6 January 2009 |publisher=[[Jet Propulsion Laboratory]] & [[Princeton University]] }}</ref> Spitzer wrote a 1946 report for [[RAND Corporation]] describing the advantages of an extraterrestrial observatory and how it could be realized with available or upcoming technology.<ref>{{cite book |author=Carolyn Collins Petersen |author2=John C. Brandt |title=Hubble vision: further adventures with the Hubble Space Telescope |publisher=CUP Archive |date=1998 |page=[https://archive.org/details/hubblevisionfurt0000pete/page/193 193] |isbn=978-0-521-59291-8 |url=https://archive.org/details/hubblevisionfurt0000pete/page/193 }}</ref><ref>{{cite book |last=Zimmerman |first=Robert |title=The universe in a mirror: the saga of the Hubble Telescope and the visionaries who built it |publisher=Princeton University Press |date=2008 |page=[https://archive.org/details/universeinmirror00zimm/page/10 10] |isbn=978-0-691-13297-6 |url-access=registration |url=https://archive.org/details/universeinmirror00zimm/page/10 }}</ref> He has been cited for his pioneering contributions to [[rocket]]ry and [[astronomy]], as well as "his vision and leadership in articulating the advantages and benefits to be realized from the Space Telescope Program."<ref name="spitzer_bio"/>

The {{USD|776 million}}<ref name="jpl-cost">{{Cite web |title=Spitzer Space Telescope Fast Facts |url=https://www.jpl.nasa.gov/news/press_kits/spitzer/quick-facts/ |url-status=live |archive-url=https://web.archive.org/web/20240214212413/https://www.jpl.nasa.gov/news/press_kits/spitzer/quick-facts/ |archive-date=14 February 2024 |access-date=21 August 2020 |publisher=[[Jet Propulsion Laboratory]] }}</ref> Spitzer was launched on 25 August 2003 at 05:35:39&nbsp;[[UTC]] from [[Cape Canaveral Air Force Station|Cape Canaveral]] [[Cape Canaveral Air Force Station Space Launch Complex 17|SLC-17B]] aboard a [[Delta II]] 7920H rocket.<ref name="sfnow20030825">{{Cite news |last=Harwood |first=William |date=25 August 2003 |title=300th Delta rocket launches new window on Universe |url=https://www.spaceflightnow.com/delta/d298/ |url-status=live |archive-url=https://web.archive.org/web/20230321020827/https://www.spaceflightnow.com/delta/d298/ |archive-date=21 March 2023 |access-date=1 December 2016 |work=Spaceflight Now for [[CBS News]] }}</ref> It was placed into a [[heliocentric]] (as opposed to a [[geocentric]]) orbit trailing and drifting away from Earth's orbit at approximately 0.1 [[astronomical unit]]s per year (an [[Earth-trailing orbit|"Earth-trailing" orbit]]<ref name=nasa20070422/>).

The [[primary mirror]] is {{convert|85|cm|in|sp=us}} in diameter, {{f/|12|link=yes}}, made of [[beryllium]] and was cooled to {{convert|5.5|K|C F|sigfig=3|lk=in}}. The [[satellite]] contains three instruments that allowed it to perform astronomical imaging and [[photometry (astronomy)|photometry]] from 3.6 to 160&nbsp;micrometers, [[spectroscopy]] from 5.2 to 38&nbsp;micrometers, and [[spectrophotometry]] from 55 to 95&nbsp;micrometers.<ref name="handbook3.2" />

== History ==
{{more citations needed section|date=January 2020}}
[[File:Atmospheric_electromagnetic_opacity.svg|thumb|301x301px|Rough plot of Earth's atmospheric [[transmittance]] (or opacity) to various wavelengths of electromagnetic radiation, including visible light.]]
By the early 1970s, astronomers began to consider the possibility of placing an [[infrared telescope]] above the obscuring effects of Earth's atmosphere. Most of the infrared spectrum is outside the [[optical window]], meaning they are strongly absorbed by the atmosphere, except for the [[infrared window]].

In 1979, a report from the National Research Council of the [[National Academy of Sciences]], ''A Strategy for Space Astronomy and Astrophysics for the 1980s'', identified a Shuttle Infrared Telescope Facility (SIRTF)<ref name="NRC_report">{{Cite report |title=Strategy for Space Astronomy and Astrophysics for the 1980's |date=1979 |publisher=The [[National Academies Press]] |doi=10.17226/19837 |page=19 |isbn=978-0-309-33285-9 |chapter-url=https://nap.nationalacademies.org/read/19837/chapter/3#19 |chapter=Strategy and Recommendations }}</ref> as "one of two major astrophysics facilities [to be developed] for [[Spacelab]]", a shuttle-borne platform. Anticipating the major results from an upcoming Explorer satellite and from the Shuttle mission, the report also favored the "study and development of ... long-duration spaceflights of infrared telescopes cooled to cryogenic temperatures<ref name="1980_Decadal">{{Cite book |url=https://www.nap.edu/read/549/chapter/8#161 |title=Astronomy and Astrophysics for the 1980's, Volume 1: Report of the Astronomy Survey Committee) |date=1982 |publisher=The [[National Academies Press]] |isbn=978-0-309-03249-0 |pages=54 |doi=10.17226/549 |hdl=2060/19830018496 }}</ref>."

The launch in January 1983 of the [[IRAS|Infrared Astronomical Satellite]] (IRAS), jointly developed by the United States, the Netherlands, and the United Kingdom, to conduct the first far-infrared survey of the sky, whetted the appetites of scientists worldwide for follow-up space missions capitalizing on the rapid improvements in infrared detector technology.

Earlier infrared observations had been made by both space-based and ground-based [[observatory|observatories]]. Ground-based observatories have the drawback that at infrared [[wavelength]]s or [[frequency|frequencies]], both the Earth's [[earth's atmosphere|atmosphere]] and the telescope itself will radiate (glow) brightly. Additionally, the atmosphere is opaque at most infrared wavelengths. This necessitates lengthy exposure times and greatly decreases the ability to detect faint objects. It could be compared to trying to observe the stars in visible light at noon from a telescope built out of light bulbs. Previous space observatories (such as [[IRAS]], the Infrared Astronomical Satellite, and [[Infrared Space Observatory|ISO]], the Infrared Space Observatory) were launched during the 1980s and 1990s and great advances in astronomical technology have been made since then.

{{multiple image |align=left |direction=horizontal
 |image1  = Ksc arrive04.jpg
 |width1  = 120
 |caption1= The SIRTF in a Kennedy Space Center clean room.
 |image2  = 300th Delta launches with Spitzer.jpg
 |width2  = 154
 |caption2= The launch of SIRTF in 2003 aboard the 300th Delta rocket.
}}

Most of the early concepts envisioned repeated flights aboard the NASA Space Shuttle. This approach was developed in an era when the Shuttle program was expected to support weekly flights of up to 30 days duration. A May 1983 NASA Announcement of Opportunity described SIRTF as a Shuttle-attached mission with an evolving scientific instrument payload. Several flights were anticipated with a probable transition into a more extended mode of operation, possibly in association with a future space platform or space station. SIRTF would be a 1-meter class, cryogenically cooled, multi-user facility consisting of a telescope and associated focal plane instruments mounted on a general-purpose Instrument Pointing System to be developed by [[NASA Ames]]. SIRTF would be launched on the Space Shuttle and remain attached to the Shuttle as a [[Spacelab]] payload during astronomical observations, after which it would be returned to Earth for refurbishment prior to re-flight. The first flight was expected to occur about 1990 with the succeeding flights anticipated beginning approximately one year later. However, the Spacelab-2 flight aboard [[STS-51-F]] showed that the Shuttle environment was poorly suited to an onboard infrared telescope due to contamination from the relatively "dirty" vacuum associated with the orbiters. By September 1983, NASA was considering the "possibility of a long duration [free-flyer] SIRTF mission".<ref name="nasa-spitzer-infrared">{{Cite web |last=Watanabe |first=Susan |date=22 November 2007 |title=Studying the Universe in Infrared |url=http://www.nasa.gov/mission_pages/spitzer/infrared/index.html |url-status=dead |archive-url=https://web.archive.org/web/20190707072050/https://www.nasa.gov/mission_pages/spitzer/infrared/index.html |archive-date=7 July 2019 |access-date=8 December 2007 |publisher=[[NASA]] }}</ref><ref name="ask-mag-25">{{Cite magazine |last=Kwok |first=Johnny |date=1 October 2006 |title=Finding a Way: The Spitzer Space Telescope Story |url=https://appel.nasa.gov/2006/10/01/finding-a-way-the-spitzer-space-telescope-story/ |url-status=live |archive-url=https://web.archive.org/web/20220925234705/https://appel.nasa.gov/2006/10/01/finding-a-way-the-spitzer-space-telescope-story/ |archive-date=25 September 2022 |access-date=9 December 2007 |magazine=NASA ASK Magazine |publisher=[[NASA]] |issue=25 }}</ref>

Spitzer is the only one of the [[Great Observatories]] not launched by the [[Space Shuttle]], as was originally intended{{Citation needed|date=May 2021|reason=The claim that SIRTF/Spitzer was ever planned to launch specifically with a Shuttle-Centaur system is unverified}}. However, after the 1986 [[STS-51-L|Challenger disaster]], the [[Shuttle-Centaur]] upper stage, which would have been required to place it into its final orbit, was abandoned. The mission underwent a series of redesigns during the 1990s, primarily due to budget considerations. This resulted in a much smaller but still fully capable mission that could use the smaller Delta II expendable launch vehicle.<ref>{{cite book |last=Rieke |first=George |title=The Last of the Great Observatories: Spitzer and the Era of Faster, Better, Cheaper at NASA |publisher=The University of Arizona Press |date=2006 |page=[https://www.bookdepository.com/Last-Great-Observatories-George-H-Rieke/9780816525584] |isbn=0-8165-2558-7 }}</ref>
{{multiple image
| align = center
| direction = horizontal
| width = 250px
| header = Animation of Spitzer Space Telescope
| image1 = Animation of Spitzer Space Telescope trajectory around Earth.gif
| caption1 = Around the Earth
| image2 = Animation of Spitzer Space Telescope around Sun - Frame rotating with Earth.gif
| caption2 = Around the Sun - Frame rotating with the Earth
| footer ={{legend2|magenta| Spitzer Space Telescope }}{{·}}{{legend2| RoyalBlue |[[Earth]]}}{{·}}{{legend2| Yellow|[[Sun]]}}
}}

One of the most important advances of this redesign was an [[List_of_orbits#Special_classifications| Earth-trailing orbit]]<!-- bolded per [[WP:MOSBOLD]] as a redirect target -->.<ref name=nasa20070422/> Cryogenic satellites that require liquid helium (LHe, T ≈ 4 K) temperatures in near-Earth orbit are typically exposed to a large heat load from Earth, and consequently require large amounts of LHe coolant, which then tends to dominate the total payload mass and limits mission life. Placing the satellite in solar orbit far from Earth allowed innovative passive cooling. The sun shield protected the rest of the spacecraft from the Sun's heat, the far side of the spacecraft was painted black to enhance passive radiation of heat, and the spacecraft bus was thermally isolated from the telescope. All of these design choices combined to drastically reduce the total mass of helium needed, resulting in an overall smaller and lighter payload, resulting in major cost savings, but with a mirror the same diameter as originally designed. This orbit also simplified telescope pointing, but did require the [[NASA Deep Space Network]] for communications.{{citation needed|date=January 2020}}

The primary instrument package (telescope and cryogenic chamber) was developed by [[Ball Aerospace & Technologies]], in [[Boulder, Colorado]]. The individual instruments were developed jointly by industrial, academic, and government institutions. The principals were [[Cornell University]], the [[University of Arizona]], the [[Smithsonian Astrophysical Observatory]], [[Ball Aerospace]], and [[Goddard Spaceflight Center]]. The shorter-wavelength infrared detectors were developed by [[Raytheon]] in [[Goleta, California]]. Raytheon used [[indium antimonide]] and a [[Dopant|doped]] [[silicon]] detector in the creation of the infrared detectors. These detectors are 100 times more sensitive than what was available at the beginning of the project during the 1980s.<ref name="raytheon-20040108">{{Cite press release |editor-last=Kopec |editor-first=Janet |date=8 January 2004 |title=Raytheon Technology Enables Superior Space Images From Spitzer Space Telescope |url=http://investor.raytheon.com/phoenix.zhtml?c=84193&p=irol-newsArticle_Print&ID=483065&highlight= |url-status=live |archive-url=https://web.archive.org/web/20180809112609/http://investor.raytheon.com/phoenix.zhtml?c=84193&p=irol-newsArticle_Print&ID=483065&highlight= |archive-date=9 August 2018 |publisher=[[Raytheon]] }}</ref> The far-infrared detectors (70–160 micrometers) were developed jointly by the University of Arizona and [[Lawrence Berkeley National Laboratory]] using [[gallium]]-doped [[germanium]]. The spacecraft was built by [[Lockheed Martin]]. The mission was operated and managed by the [[Jet Propulsion Laboratory]] and the ''Spitzer Science Center'',<ref>[http://www.spitzer.caltech.edu/ Spitzer Science Center Home Page -- Public information].</ref> located at IPAC on the [[Caltech]] campus in Pasadena, California.{{citation needed|date=January 2020}}

[[File:Telescope-spitzer-en-coupe.png|thumb|Schematic view of Spitzer:<br />'''A Optics''' : 1 - secondary mirror;  3 - primary mirror; 2 -  outer shell;<br />'''B Cryostat''': 4 - instruments; 10 - helium tank;<br />'''C Service module''': 5 - service module shield; 6 - star tracker; 7 - batteries; 8 - high-gain antenna; 9 - nitrogen tank;<br />'''D Solar panels''']]

===Launch and commissioning===
{{empty section|date=December 2021}}

===Warm mission and end of mission===
Spitzer ran out of liquid helium coolant on 15 May 2009, which stopped far-IR observations. Only the IRAC instrument remained in use, and only at the two shorter wavelength bands (3.6&nbsp;μm and 4.5&nbsp;μm). The telescope equilibrium temperature was then around {{convert|30|K|C F|0|abbr=on}}, and IRAC continued to produce valuable images at those wavelengths as the "Spitzer Warm Mission".<ref name="nasa-20090508">{{Cite press release |last1=Clavin |first1=Whitney B. |last2=Harrington |first2=J. D. |date=5 August 2009 |title=NASA's Spitzer Sees the Cosmos Through 'Warm' Infrared Eyes |url=https://www.jpl.nasa.gov/news/nasas-spitzer-sees-the-cosmos-through-warm-infrared-eyes |url-status=live |archive-url=https://web.archive.org/web/20230326021157/https://www.jpl.nasa.gov/news/nasas-spitzer-sees-the-cosmos-through-warm-infrared-eyes |archive-date=26 March 2023 |access-date=30 January 2016 |publisher=[[NASA]] |id=2009-116 }}</ref>

Late in the mission, ~2016, Spitzer's distance to Earth and the shape of its orbit meant the spacecraft had to pitch over at an extreme angle to aim its antenna at Earth.<ref name="nasa20160825"/> The solar panels were not fully illuminated at this angle, and this limited those communications to 2.5 hours due to the battery drain.<ref name="Sp-life">{{Cite press release |editor-last=Cofield |editor-first=Calla |date=13 June 2019 |title=How NASA's Spitzer Has Stayed Alive for So Long |url=https://www.spitzer.caltech.edu/news/ssc2019-10-how-nasas-spitzer-has-stayed-alive-for-so-long |url-status=live |archive-url=https://web.archive.org/web/20240201101520/https://www.spitzer.caltech.edu/news/ssc2019-10-how-nasas-spitzer-has-stayed-alive-for-so-long |archive-date=1 February 2024 |publisher=[[Jet Propulsion Laboratory]] |id=ssc2019-10 }}</ref> The telescope was retired on 30 January 2020<ref name='SciAm 2019'>[https://www.scientificamerican.com/article/ending-in-2020-nasas-infrared-spitzer-mission-leaves-a-gap-in-astronomy/?redirect=1 Ending in 2020, NASA's Infrared Spitzer Mission Leaves a Gap in Astronomy.] Jonathan O'Callaghan. ''[[Scientific American]]''. June 4, 2019.</ref> when NASA sent a shutdown signal to the telescope from the [[Goldstone Deep Space Communications Complex]] (GDSCC) instructing the telescope to go into safe mode.<ref name="wired-20200129">{{Cite magazine |last=Oberhaus |first=Daniel |date=29 January 2020 |title=RIP Spitzer, the Coolest Heat Telescope in the Solar System |url=https://www.wired.com/story/rip-spitzer-telescope/ |url-status=live |archive-url=https://web.archive.org/web/20230724030247/https://www.wired.com/story/rip-spitzer-telescope/ |archive-date=24 July 2023 |access-date=29 January 2020 |magazine=[[Wired (magazine)|Wired]] }}</ref>  After receiving confirmation that the command was successful, Spitzer Project Manager Joseph Hunt officially declared that the mission had ended.<ref name="jpl-20200130">{{Cite press release |editor-last=Hautaluoma |editor-first=Grey |editor2-last=Landau |editor2-first=Elizabeth |editor3-last=Cofield |editor3-first=Calla |date=30 January 2020 |title=NASA's Spitzer Space Telescope Ends Mission of Astronomical Discovery |url=https://www.spitzer.caltech.edu/news/ssc2020-08-nasas-spitzer-space-telescope-ends-mission-of-astronomical-discovery |url-status=live |archive-url=https://web.archive.org/web/20240201101408/https://www.spitzer.caltech.edu/news/ssc2020-08-nasas-spitzer-space-telescope-ends-mission-of-astronomical-discovery |archive-date=1 February 2024 |access-date=10 February 2020 |publisher=[[Jet Propulsion Laboratory]] |id=ssc2020-08 }}</ref>

== Instruments ==
[[File:Spitzer - O CTA em testes.jpg|thumb|Cryogenic Telescope Assembly (CTA)]]

Spitzer carries three instruments on board:<ref name="spitzer-geninfo">{{Cite web |title=SSC Observatory general information page |url=http://ssc.spitzer.caltech.edu/geninfo/ |url-status=dead |archive-url=https://web.archive.org/web/20100206141933/http://ssc.spitzer.caltech.edu/geninfo/ |archive-date=6 February 2010 |access-date=4 October 2009 |publisher=[[Jet Propulsion Laboratory]] }}</ref><ref name="ssc-obs-overview">{{Cite web |title=SSC Observatory Overview |url=http://ssc.spitzer.caltech.edu/obs/overview.html |url-status=dead |archive-url=https://web.archive.org/web/20091010164717/http://ssc.spitzer.caltech.edu/obs/overview.html |archive-date=10 October 2009 |access-date=4 October 2009 |publisher=[[Jet Propulsion Laboratory]] }}</ref><ref>[http://ssc.spitzer.caltech.edu/ SSC Science Information home page], 4 October 2009.</ref><ref name="ssc-obs-man">{{Cite web |title=Spitzer Observers' Manual - reference for technical instrument information, Ver 8 |url=http://ssc.spitzer.caltech.edu/documents/som/ |url-status=dead |archive-url=https://web.archive.org/web/20091011224057/http://ssc.spitzer.caltech.edu/documents/som/ |archive-date=11 October 2009 |access-date=15 August 2008 }}</ref>

; [[Infrared Array Camera]] (IRAC)
: An infrared camera which operated simultaneously on four wavelengths (3.6&nbsp;μm, 4.5&nbsp;μm, 5.8&nbsp;μm and 8&nbsp;μm). Each module used a 256×256-pixel detector—the short-wavelength pair used [[indium antimonide]] technology, the long-wavelength pair used arsenic-doped silicon [[impurity band conduction]] technology.<ref name="IRAC">{{Cite web |title=SSC IRAC (Mid IR camera) science users information page |url=http://ssc.spitzer.caltech.edu/irac/ |url-status=dead |archive-url=https://web.archive.org/web/20091101133320/http://ssc.spitzer.caltech.edu/irac/ |archive-date=1 November 2009 |access-date=4 October 2009 |publisher=[[Jet Propulsion Laboratory]] }}</ref> The principal investigator was [[Giovanni Fazio]] of [[Harvard-Smithsonian Center for Astrophysics|Center for Astrophysics {{!}} Harvard & Smithsonian]]; the flight hardware was built by [[NASA]] [[Goddard Space Flight Center]].
; Infrared Spectrograph (IRS)
: An infrared spectrometer with four sub-modules which operate at the wavelengths 5.3–14&nbsp;μm (low resolution), 10–19.5&nbsp;μm (high resolution), 14–40&nbsp;μm (low resolution), and 19–37&nbsp;μm (high resolution). Each module used a 128×128-pixel detector—the short-wavelength pair used arsenic-doped silicon blocked impurity band technology, the long-wavelength pair used antimony-doped silicon blocked impurity band technology.<ref name="IRS">{{Cite web |title=SSC IRS (spectrometer) science users' information page |url=http://ssc.spitzer.caltech.edu/irs/ |url-status=dead |archive-url=https://web.archive.org/web/20090803172846/http://ssc.spitzer.caltech.edu/irs/ |archive-date=3 August 2009 |access-date=4 October 2009 |publisher=[[Jet Propulsion Laboratory]] }}</ref> The principal investigator was [[James R. Houck]] of [[Cornell University]]; the flight hardware was built by [[Ball Aerospace]].
; {{anchor|MIPS}} Multiband Imaging Photometer for Spitzer (MIPS)
: Three detector arrays in the mid- to far-infrared (128 × 128 pixels at 24&nbsp;[[μm]], 32 × 32 pixels at 70&nbsp;μm, 2 × 20 pixels at 160&nbsp;μm). The 24&nbsp;μm detector is identical to one of the IRS short-wavelength modules. The 70&nbsp;μm detector used gallium-doped germanium technology, and the 160&nbsp;μm detector also used gallium-doped germanium, but with mechanical stress added to each pixel to lower the bandgap and extend sensitivity to this long-wavelength.<ref name="MIPS">{{Cite web |title=SSC MIPS (long wavelength 24um, 70um, & 160um) imaging photometer and spectrometer science users' information page |url=http://ssc.spitzer.caltech.edu/mips/ |url-status=dead |archive-url=https://web.archive.org/web/20091108121817/http://ssc.spitzer.caltech.edu/mips/ |archive-date=8 November 2009 |publisher=[[Jet Propulsion Laboratory]] }}</ref> The principal investigator was [[George H. Rieke]] of the [[University of Arizona]]; the flight hardware was built by [[Ball Aerospace]].

All three instruments used liquid helium for cooling the sensors. Once the helium was exhausted, only the two shorter wavelengths in IRAC were used in the "warm mission".

[[File:Ssc2004-04a.jpg|thumb|center|upright=2.0|A [[Henize 206]] viewed by different instruments in March 2004. The separate IRAC and MIPS images are at right.]]

== Results ==

While some time on the telescope was reserved for participating institutions and crucial projects, astronomers around the world also had the opportunity to submit proposals for observing time. Prior to launch, there was a proposal call for large, coherent investigations using Spitzer. If the telescope failed early and/or ran out of cryogen very quickly, these so-called Legacy Projects would ensure the best possible science could be obtained quickly in the early months of the mission. As a requirement tied to the funding these Legacy teams received, the teams had to deliver high-level data products back to the Spitzer Science Center (and the [[Infrared_Science_Archive | NASA/IPAC Infrared Science Archive]]) for use by the community, again ensuring the rapid scientific return of the mission. The international scientific community quickly realized the value of delivering products for others to use, and even though Legacy projects were no longer explicitly solicited in subsequent proposal calls, teams continued to deliver products to the community. The Spitzer Science Center later reinstated named "Legacy" projects (and later still "Exploration Science" projects) in response to this community-driven effort.<ref name="ipac-spitzer-legacy">{{Cite web |title=Spitzer Documentation & Tools: Legacy Programs |url=https://irsa.ipac.caltech.edu/data/SPITZER/docs/spitzermission/observingprograms/legacy/ |url-status=live |archive-url=https://web.archive.org/web/20231210054927/https://irsa.ipac.caltech.edu/data/SPITZER/docs/spitzermission/observingprograms/legacy/ |archive-date=10 December 2023 |access-date=26 August 2020 |website=NASA/IPAC Infrared Science Archive |publisher=[[NASA]] }}</ref>

Important targets included forming stars ([[young stellar object]]s, or YSOs), planets, and other galaxies. Images are freely available for educational and journalistic purposes.<ref name="ipac-image-policy">{{Cite web |title=IPAC Image Use Policy |url=https://www.ipac.caltech.edu/page/image-use-policy |url-status=live |archive-url=https://web.archive.org/web/20240201100849/https://www.ipac.caltech.edu/page/image-use-policy |archive-date=1 February 2024 |access-date=26 August 2020 |publisher=[[NASA]] IPAC }}</ref><ref>{{cite web |title=Spitzer Space Telescope Images |url=https://astropix.ipac.caltech.edu/provider/spitzer |website=Astropix |access-date=26 August 2020}}</ref>

[[File:PIA23126-CepheusC&Bregions-SpitzerST-20190530.jpg|thumb|center|800px|<div align="center">The [[Cepheus (constellation)|Cepheus C & B Regions.]] – The Spitzer Space Telescope (30 May 2019).</div>]]
[[File:Dark Globule in IC 1396 (crop).jpg|thumb|The Spitzer's [[first light (astronomy)|first light]] image of [[IC 1396]].]]
The first released images from Spitzer were designed to show off the abilities of the telescope and showed a glowing stellar nursery, a big swirling, dusty [[galaxy]], a disc of planet-forming debris, and organic material in the distant universe. Since then, many monthly press releases have highlighted Spitzer{{'s}} capabilities, as the NASA and [[ESA]] images do for the [[Hubble Space Telescope]].

As one of its most noteworthy observations, in 2005, Spitzer became one of the first telescopes to directly capture light from [[exoplanet]]s, namely the "hot Jupiters" [[HD 209458 b]] and [[TrES-1b]], although it did not resolve that light into actual images.<ref>[http://www.spitzer.caltech.edu/news/189-ssc2005-09-NASA-s-Spitzer-Marks-Beginning-of-New-Age-of-Planetary-Science Press Release: NASA's Spitzer Marks Beginning of New Age of Planetary Science].</ref> This was one of the first times the light from extrasolar planets had been directly detected; earlier observations had been indirectly made by drawing conclusions from behaviors of the stars the planets were orbiting. The telescope also discovered in April 2005 that [[Cohen-kuhi Tau/4]] had a planetary disk that was vastly younger and contained less mass than previously theorized, leading to new understandings of how planets are formed.

[[File:Comets Kick up Dust in Helix Nebula (PIA09178).jpg|thumb|left|The [[Helix Nebula]], blue shows infrared light of 3.6 to 4.5 micrometers, green shows infrared light of 5.8 to 8 micrometers, and red shows infrared light of 24 micrometers.]]

In 2004, it was reported that Spitzer had spotted a faintly glowing body that may be the youngest star ever seen. The telescope was trained on a core of gas and dust known as [[L1014]] which had previously appeared completely dark to ground-based observatories and to ISO ([[Infrared Space Observatory]]), a predecessor to Spitzer. The advanced technology of Spitzer revealed a bright red hot spot in the middle of L1014.

Scientists from the [[University of Texas at Austin]], who discovered the object, believe the hot spot to be an example of early star development, with the young star collecting gas and dust from the cloud around it. Early speculation about the hot spot was that it might have been the faint light of another core that lies 10 times further from Earth but along the same line of sight as L1014. Follow-up observation from ground-based near-infrared observatories detected a faint fan-shaped glow in the same location as the object found by Spitzer. That glow is too feeble to have come from the more distant core, leading to the conclusion that the object is located within L1014. (Young ''et al.'', 2004)

In 2005, astronomers from the [[University of Wisconsin System|University of Wisconsin]] at [[University of Wisconsin–Madison|Madison]] and [[University of Wisconsin–Whitewater|Whitewater]] determined, on the basis of 400 hours of observation on the Spitzer Space Telescope, that the [[Milky Way]] galaxy has a more substantial [[barred spiral galaxy|bar structure]] across its core than previously recognized.

[[File:False-Color Image of Double Helix Nebula.jpg|thumb|upright|An artificial color image of the [[Double Helix Nebula]], thought to be generated at the galactic center by magnetic torsion 1000 times greater than the Sun's.]]

Also in 2005, astronomers [[Alexander Kashlinsky]] and [[John C. Mather|John Mather]] of NASA's [[Goddard Space Flight Center]] reported that one of Spitzer{{'s}} earliest images may have captured the light of the first stars in the universe. An image of a [[quasar]] in the [[Draco (constellation)|Draco]] [[constellation]], intended only to help [[calibrate]] the telescope, was found to contain an infrared glow after the light of known objects was removed. Kashlinsky and Mather are convinced that the numerous blobs in this glow are the light of stars that formed as early as 100&nbsp;million years after the [[Big Bang]], [[redshift]]ed by [[cosmic expansion]].<ref>[http://www.sciam.com/article.cfm?chanID=sa007&articleID=0009A468-3F5E-1369-BF5E83414B7F0000 Infrared Glow of First Stars Found: Scientific American] {{webarchive|url=https://web.archive.org/web/20071010052138/http://www.sciam.com/article.cfm?chanID=sa007&articleID=0009A468-3F5E-1369-BF5E83414B7F0000 |date=10 October 2007 }}.</ref>

In March 2006, astronomers reported an {{convert|80|ly|pc|lk=on|adj=mid|-long}} nebula near the center of the Milky Way Galaxy, the [[Double Helix Nebula]], which is, as the name implies, twisted into a double spiral shape. This is thought to be evidence of massive magnetic fields generated by the gas disc orbiting the [[supermassive black hole]] at the galaxy's center, {{convert|300|ly|pc}} from the nebula and {{convert|25000|ly|pc}} from Earth. This nebula was discovered by Spitzer and published in the magazine ''[[Nature (journal)|Nature]]'' on 16 March 2006.

In May 2007, astronomers successfully mapped the atmospheric temperature of [[HD 189733 b]], thus obtaining the first map of some kind of an extrasolar planet.

Starting in September 2006, the telescope participated in a series of surveys called the [[Gould Belt Survey]], observing the [[Gould Belt|Gould's Belt]] region in multiple wavelengths. The first set of observations by the Spitzer Space Telescope was completed from 21 September 2006 through 27 September. Resulting from these observations, the team of astronomers led by Dr. Robert Gutermuth, of the [[Harvard-Smithsonian Center for Astrophysics|Center for Astrophysics {{!}} Harvard & Smithsonian]] reported the discovery of [[Serpens south|Serpens South]], a cluster of 50 young stars in the [[Serpens]] constellation.

[[File:Andromeda galaxy Ssc2005-20a1.jpg|thumb|left|250px|The [[Andromeda Galaxy]] imaged by MIPS at 24 micrometers.]]

Scientists have long wondered how tiny silicate crystals, which need high temperatures to form, have found their way into frozen comets, born in the very cold environment of the Solar System's outer edges. The crystals would have begun as non-crystallized, amorphous silicate particles, part of the mix of gas and dust from which the Solar System developed. This mystery has deepened with the results of the ''[[Stardust (spacecraft)|Stardust]]'' sample return mission, which captured particles from Comet [[Wild 2]]. Many of the Stardust particles were found to have formed at temperatures in excess of 1,000 K.

In May 2009, Spitzer researchers from Germany, Hungary, and the Netherlands found that amorphous silicate appears to have been transformed into crystalline form by an outburst from a star. They detected the infrared signature of [[forsterite]] silicate crystals on the disk of dust and gas surrounding the star EX Lupi during one of its frequent flare-ups, or outbursts, seen by Spitzer in April 2008. These crystals were not present in Spitzer{{'s}} previous observations of the star's disk during one of its quiet periods. These crystals appear to have formed by radiative heating of the dust within 0.5 AU of EX Lupi.<ref name="jpl-20090513">{{Cite press release |editor-last=Clavin |editor-first=Whitney |title=Spitzer Catches Star Cooking Up Comet Crystals |url=https://www.jpl.nasa.gov/news/spitzer-catches-star-cooking-up-comet-crystals |url-status=live |archive-url=https://web.archive.org/web/20240107155145/https://www.jpl.nasa.gov/news/spitzer-catches-star-cooking-up-comet-crystals |archive-date=7 January 2024 |publisher=[[Jet Propulsion Laboratory]] |id=2009-083 }}</ref><ref>{{cite journal |last=Ábrahám |first=P. |display-authors=etal |title=Episodic formation of cometary material in the outburst of a young Sun-like star |journal=[[Nature (journal)|Nature]] |date=14 May 2009 |doi=10.1038/nature08004 |bibcode=2009Natur.459..224A |volume=459 |issue=7244 |pages=224–226 |arxiv=0906.3161 |pmid=19444209|s2cid=4426934 }}</ref>

In August 2009, the telescope found evidence of a high-speed collision between two burgeoning planets orbiting a young star.<ref name="bbc-20090811">{{Cite news |date=11 August 2009 |title=Traces of planet collision found |url=http://news.bbc.co.uk/2/hi/science/nature/8195467.stm |url-status=live |archive-url=https://web.archive.org/web/20231210020045/http://news.bbc.co.uk/2/hi/science/nature/8195467.stm |archive-date=10 December 2023 |work=[[BBC News]] }}</ref>

In October 2009, astronomers Anne J. Verbiscer, Michael F. Skrutskie, and Douglas P. Hamilton published findings of the "[[Phoebe ring]]" of [[Saturn]], which was found with the telescope; the ring is a huge, tenuous disc of material extending from 128 to 207 times the radius of Saturn.<ref>{{cite journal |last=Verbiscer |first=Anne |author2=Michael Skrutskie |author3=Douglas Hamilton |title=Saturn's largest ring |journal=[[Nature (journal)|Nature]] |date=7 October 2009 |doi=10.1038/nature08515 |pmid=19812546 |bibcode=2009Natur.461.1098V |volume=461 |issue=7267 |pages=1098–100|s2cid=4349726 }}</ref>

=== GLIMPSE and MIPSGAL surveys ===
GLIMPSE, the ''Galactic Legacy Infrared Mid-Plane Survey Extraordinaire'', was a series of surveys that spanned 360° of the inner region of the Milky Way galaxy, which provided the first large-scale mapping of the galaxy.<ref name="jpl-20140320b">{{Cite press release |date=20 March 2014 |title=NASA's Spitzer Telescope Brings 360-Degree View of Galaxy to Our Fingertips |url=https://www.spitzer.caltech.edu/news/ssc2014-02-nasas-spitzer-telescope-brings-360-degree-view-of-galaxy-to-our-fingertips |url-status=live |archive-url=https://web.archive.org/web/20230928004329/https://www.spitzer.caltech.edu/news/ssc2014-02-nasas-spitzer-telescope-brings-360-degree-view-of-galaxy-to-our-fingertips |archive-date=28 September 2023 |publisher=[[Jet Propulsion Laboratory]] |id=ssc2014-02 }}</ref><ref name="jpl-20200825">{{Cite press release |editor-last=Cofield |editor-first=Calla |date=25 August 2020 |title=Where Are Stars Made? NASA's Spitzer Spies a Hot Spot |url=https://www.nasa.gov/centers-and-facilities/jpl/where-are-stars-made-nasas-spitzer-spies-a-hot-spot/ |url-status=live |archive-url=https://web.archive.org/web/20240226112546/https://www.nasa.gov/centers-and-facilities/jpl/where-are-stars-made-nasas-spitzer-spies-a-hot-spot/ |archive-date=26 February 2024 |access-date=31 August 2020 |publisher=[[NASA]] & [[Jet Propulsion Laboratory]] |id=ssc2020-14 }}</ref> It consists of more than 2&nbsp;million snapshots taken in four separate wavelengths using the Infrared Array Camera.<ref name="glimpse">[http://www.astro.wisc.edu/sirtf/ Galactic Legacy Infrared Mid-Plane Survey Extraordinaire] {{Webarchive|url=https://web.archive.org/web/20210508030004/http://www.astro.wisc.edu/sirtf/ |date=8 May 2021 }}, University of Wisconsin–Madison Department of Astronomy</ref> The images were taken over a 10-year period beginning in 2003 when Spitzer launched.<ref name="jpl-20140320">{{Cite press release |date=20 March 2014 |title=GLIMPSE the Galaxy All the Way Around |url=https://www.spitzer.caltech.edu/image/ssc2014-02a-glimpse-the-galaxy-all-the-way-around |url-status=live |archive-url=https://web.archive.org/web/20231226180412/https://www.spitzer.caltech.edu/image/ssc2014-02a-glimpse-the-galaxy-all-the-way-around |archive-date=26 December 2023 |access-date=26 August 2020 |publisher=[[Jet Propulsion Laboratory]] |id=ssc2014-02a }}</ref>

MIPSGAL, a similar survey that complements GLIMPSE, covers 248° of the galactic disk<ref>{{cite web |title=A 24 and 70 Micron Survey of the Inner Galactic Disk with MIPS (MIPSGAL) Data Collection Atlas |url=https://irsa.ipac.caltech.edu/data/SPITZER/MIPSGAL/ |website=NASA/IPAC Infrared Science Archive (IRSA) |access-date=26 August 2020}}</ref> using the 24 and 70 μm channels of the MIPS instrument.<ref>{{cite book |last1=Werner |first1=Michael |last2=Eisenhardt |first2=Peter |title=More Things in the Heavens: How Infrared Astronomy is Expanding Our View of the Universe |date=2019 |publisher=Princeton University Press |isbn=978-0-691-17554-6 |page=101 }}</ref>

On 3 June 2008, scientists unveiled the largest, most detailed infrared portrait of the [[Milky Way]], created by stitching together more than 800,000 snapshots, at the 212th meeting of the [[American Astronomical Society]] in [[St. Louis]], [[Missouri]].<ref name="jpl-ssc2008-11">{{Cite press release |editor-last=Clavin |editor-first=Whitney |date=3 June 2008 |title=Spitzer Captures Stellar Coming of Age in Our Galaxy |url=https://www.spitzer.caltech.edu/news/ssc2008-11-spitzer-captures-stellar-coming-of-age-in-our-galaxy |url-status=live |archive-url=https://web.archive.org/web/20230928015650/https://www.spitzer.caltech.edu/news/ssc2008-11-spitzer-captures-stellar-coming-of-age-in-our-galaxy |archive-date=28 September 2023 |website=www.spitzer.caltech.edu |publisher=[[Jet Propulsion Laboratory]] |id=ssc2008-11, jpl2008-095 }}</ref><ref>{{Cite web |url=http://legacy.spitzer.caltech.edu/Media/releases/ssc2008-11/visuals.shtml |title=Released Images and Videos of Milky Way Mosaic |access-date=11 May 2014 |archive-date=4 March 2016 |archive-url=https://web.archive.org/web/20160304031221/http://legacy.spitzer.caltech.edu/Media/releases/ssc2008-11/visuals.shtml |url-status=dead }}</ref> This composite survey is now viewable with the GLIMPSE/MIPSGAL Viewer.<ref>{{Cite web|url=http://www.alienearths.org/glimpse/glimpse.php|title=Glimpse|website=www.alienearths.org}}</ref>

=== 2010s ===
[[File:Protostar HOPS-68 in Orion (ssc2011-06c1).jpg|thumb|An arrow points to the embryonic star HOPS-68, where scientists believe [[forsterite]] crystals are raining down onto the central dust disk.]]

Spitzer observations, announced in May 2011, indicate that tiny [[forsterite]] crystals might be falling down like rain on to the [[protostar]] HOPS-68. The discovery of the forsterite crystals in the outer collapsing cloud of the protostar is surprising because the crystals form at lava-like high temperatures, yet they are found in the molecular cloud where the temperatures are about {{convert|-170|C|K F}}. This led the team of astronomers to speculate that the [[bipolar outflow]] from the young star may be transporting the forsterite crystals from near the star's surface to the chilly outer cloud.<ref name="jpl-2011-161">{{Cite press release |editor-last=Clavin |editor-first=Whitney |editor2-last=Perrotto |editor2-first=Trent |date=26 May 2011 |title=Spitzer Sees Crystal 'Rain' in Outer Clouds of Infant Star |url=https://www.jpl.nasa.gov/news/spitzer-sees-crystal-rain-in-outer-clouds-of-infant-star |url-status=live |archive-url=https://web.archive.org/web/20240225153004/https://www.jpl.nasa.gov/news/spitzer-sees-crystal-rain-in-outer-clouds-of-infant-star |archive-date=25 February 2024 |publisher=[[Jet Propulsion Laboratory]] |id=2011-161 }}</ref><ref name="apjournal-201106">{{Cite journal |last1=Poteet |first1=Charles A. |last2=Megeath |first2=S. Thomas |last3=Watson |first3=Dan M. |last4=Calvet |first4=Nuria |last5=Remming |first5=Ian S. |last6=McClure |first6=Melissa K. |last7=Sargent |first7=Benjamin A. |last8=Fischer |first8=William J. |last9=Furlan |first9=Elise |last10=Allen |first10=Lori E. |author10-link=Lori Allen (astronomer)|last11=Bjorkman |first11=Jon E. |last12=Hartmann |first12=Lee |last13=Muzerolle |first13=James |last14=Tobin |first14=John J. |last15=Ali |first15=Babar |date=June 2011 |title=A Spitzer Infrared Spectrograph Detection of Crystalline Silicates in a Protostellar Envelope |url=https://authors.library.caltech.edu/25204/1/Poteet2011p15620Astrophys_J_Lett.pdf |url-status=live |journal=[[The Astrophysical Journal|The Astrophysical Journal Letters]] |publisher=[[American Astronomical Society]] |volume=733 |issue=2 |pages=L32 |arxiv=1104.4498 |bibcode=2011ApJ...733L..32P |doi=10.1088/2041-8205/733/2/L32 |s2cid=28545814 |archive-url=https://web.archive.org/web/20240226110600/https://s3.us-west-2.amazonaws.com/caltechauthors/71/cb/ba9a-895a-4771-9499-6c997f518ae3/data?response-content-type=application%2Foctet-stream&response-content-disposition=attachment%3B%20filename%3DPoteet2011p15620Astrophys_J_Lett.pdf&X-Amz-Algorithm=AWS4-HMAC-SHA256&X-Amz-Credential=AKIARCVIVNNAKP37N3MU%2F20240226%2Fus-west-2%2Fs3%2Faws4_request&X-Amz-Date=20240226T110600Z&X-Amz-Expires=60&X-Amz-SignedHeaders=host&X-Amz-Signature=9153090e29dbc1962e08d57b06bce58d58399bc83fb22570c2df1d3b5eefc25f |archive-date=26 February 2024 |doi-access=free }}</ref>

In January 2012, it was reported that further analysis of the Spitzer observations of EX Lupi can be understood if the forsterite crystalline dust was moving away from the protostar at a remarkable average speed of {{convert|38|km/s|mi/s}}. It would appear that such high speeds can arise only if the dust grains had been ejected by a bipolar outflow close to the star.<ref>{{cite journal |last=Juhász |first=A. |display-authors=etal |title=The 2008 Outburst of EX Lup—Silicate Crystals in Motion |journal=[[The Astrophysical Journal]] |date=January 2012 |doi=10.1088/0004-637X/744/2/118 |bibcode=2012ApJ...744..118J |volume=744 |issue=2 |page=118 |arxiv=1110.3754|s2cid=53550709 }}</ref> Such observations are consistent with an astrophysical theory, developed in the early 1990s, where it was suggested that bipolar outflows garden or transform the disks of gas and dust that surround protostars by continually ejecting reprocessed, highly heated material from the inner disk, adjacent to the protostar, to regions of the accretion disk further away from the protostar.<ref>{{cite journal |last1=Liffman |first1=K. |last2=Brown |first2=M. |title=The motion and size sorting of particles ejected from a protostellar accretion disk |journal=[[Icarus (journal)|Icarus]] |date=October 1995 |doi=10.1006/icar.1995.1126 |bibcode=1995Icar..116..275L |volume=116 |issue=2 |pages=275–290}}</ref>

In April 2015, Spitzer and the [[Optical Gravitational Lensing Experiment]] were reported as co-discovering one of the most distant planets ever identified: a gas giant about {{convert|13000|ly|pc}} away from Earth.<ref name="spacecom-20150416">{{Cite news |last=Howell |first=Elizabeth |date=16 April 2015 |title=Newfound Alien Planet Is One of the Farthest Ever Detected |url=https://www.space.com/29120-alien-planet-among-farthest-known.html |url-status=live |archive-url=https://web.archive.org/web/20230926082126/https://www.space.com/29120-alien-planet-among-farthest-known.html |archive-date=26 September 2023 |access-date=14 December 2016 |work=[[Space.com]] }}</ref>

[[File:PIA21076 Brown Dwarf Microlensing (Illustration), Figure 1.jpg|thumb|An illustration of a brown dwarf combined with a graph of light curves from {{nowrap|OGLE-2015-BLG-1319}}: Ground-based data (grey), Swift (blue), and Spitzer (red).]]
In June and July 2015, the [[brown dwarf]] {{nowrap|OGLE-2015-BLG-1319}} was discovered using the [[gravitational microlensing]] detection method in a joint effort between [[Swift Gamma-Ray Burst Mission|Swift]], Spitzer, and the ground-based [[Optical Gravitational Lensing Experiment]], the first time two space telescopes have observed the same microlensing event. This method was possible because of the large separation between the two spacecraft: Swift is in low-Earth orbit while Spitzer is more than one [[astronomical unit|AU]] distant in an Earth-trailing heliocentric orbit.<ref name=nasa20070422/> This separation provided significantly different perspectives of the brown dwarf, allowing for constraints to be placed on some of the object's physical characteristics.<ref name="nasa20161110">{{cite web |url=http://www.jpl.nasa.gov/news/news.php?feature=6673 |title=NASA Space Telescopes Pinpoint Elusive Brown Dwarf |publisher=NASA{{\}}Jet Propulsion Laboratory |first=Elizabeth |last=Landau |date=10 November 2016 |access-date=18 December 2016}}</ref>

Reported in March 2016, Spitzer and Hubble were used to discover the most distant-known galaxy, [[GN-z11]]. This object was seen as it appeared 13.4&nbsp;billion years ago.<ref name="spitzer20160303">{{Cite press release |date=3 March 2016 |title=Hubble Team Breaks Cosmic Distance Record |url=https://www.spitzer.caltech.edu/news/feature16-04-hubble-team-breaks-cosmic-distance-record |url-status=live |archive-url=https://web.archive.org/web/20230928015442/https://www.spitzer.caltech.edu/news/feature16-04-hubble-team-breaks-cosmic-distance-record |archive-date=28 September 2023 |access-date=14 December 2016 |publisher=[[Jet Propulsion Laboratory]] |id=feature16-04 }}</ref><ref name="nasa20160825">{{Cite press release |last=Landau |first=Elizabeth |date=25 August 2016 |title=Spitzer Space Telescope Begins 'Beyond' Phase |url=https://www.jpl.nasa.gov/news/spitzer-space-telescope-begins-beyond-phase |url-status=live |archive-url=https://web.archive.org/web/20240220093107/https://www.jpl.nasa.gov/news/spitzer-space-telescope-begins-beyond-phase |archive-date=20 February 2024 |access-date=9 December 2016 |publisher=[[Jet Propulsion Laboratory]] |id=2016-221 }}</ref>

=== ''Spitzer Beyond'' ===
On 1 October 2016, Spitzer began its Observation Cycle 13, a {{frac|2|1|2}} year extended mission nicknamed ''Beyond''. One of the goals of this extended mission was to help prepare for the [[James Webb Space Telescope]], also an infrared telescope, by identifying candidates for more detailed observations.<ref name="nasa20160825"/>

Another aspect of the ''Beyond'' mission was the engineering challenges of operating Spitzer in its progressing orbital phase. As the spacecraft moved farther from Earth on the same orbital path from the Sun, its antenna had to point at increasingly higher angles to communicate with ground stations; this change in angle imparted more and more solar heating on the vehicle while its solar panels received less sunlight.<ref name="nasa20160825"/>

=== Planet hunter ===
[[File:Artist’s impression of the TRAPPIST-1 planetary system.jpg|thumb|An artist's impression of the TRAPPIST-1 system.]]

Spitzer was also put to work studying exoplanets thanks to creatively tweaking its hardware. This included doubling its stability by modifying its heating cycle, finding a new use for the "peak-up" camera, and analyzing the sensor at a sub-pixel level. Although in its "warm" mission, the spacecraft's passive cooling system kept the sensors at {{Convert|29|K|sigfig=3}}.<ref name="spitz">{{Cite press release |last=Hadhazy |first=Adam |date=24 September 2013 |title=How Engineers Revamped Spitzer to Probe Exoplanets |url=https://www.jpl.nasa.gov/news/how-engineers-revamped-spitzer-to-probe-exoplanets |url-status=live |archive-url=https://web.archive.org/web/20230328165829/https://www.jpl.nasa.gov/news/how-engineers-revamped-spitzer-to-probe-exoplanets |archive-date=28 March 2023 |access-date=14 December 2016 |publisher=[[Jet Propulsion Laboratory]] |id=2013-289 }}</ref> Spitzer used the [[transit photometry]] and [[gravitational microlensing]] techniques to perform these observations.<ref name="nasa20160825"/> According to NASA's Sean Carey, "We never even considered using Spitzer for studying exoplanets when it launched. ... It would have seemed ludicrous back then, but now it's an important part of what Spitzer does."<ref name="nasa20160825"/>

Examples of exoplanets discovered using Spitzer include [[HD 219134 b]] in 2015, which was shown to be a rocky planet about 1.5 times as large as Earth in a three-day orbit around its star;<ref name="nasa20150730">{{Cite press release |last1=Chou |first1=Felicia |last2=Clavin |first2=Whitney B. |date=30 July 2015 |title=NASA's Spitzer Confirms Closest Rocky Exoplanet |url=https://www.jpl.nasa.gov/news/nasas-spitzer-confirms-closest-rocky-exoplanet |url-status=live |archive-url=https://web.archive.org/web/20230407191252/https://www.jpl.nasa.gov/news/nasas-spitzer-confirms-closest-rocky-exoplanet |archive-date=7 April 2023 |access-date=15 December 2016 |publisher=[[Jet Propulsion Laboratory]] |id=2015-251 }}</ref> and an unnamed planet found using microlensing located about {{convert|13000|ly|pc}} from Earth.<ref name="nasa20150414">{{Cite press release |last1=Clavin |first1=Whitney B. |last2=Chou |first2=Felicia |date=14 April 2015 |title=NASA's Spitzer Spots Planet Deep Within Our Galaxy |url=https://www.jpl.nasa.gov/news/nasas-spitzer-spots-planet-deep-within-our-galaxy |url-status=live |archive-url=https://web.archive.org/web/20240220093147/https://www.jpl.nasa.gov/news/nasas-spitzer-spots-planet-deep-within-our-galaxy |archive-date=20 February 2024 |access-date=15 December 2016 |publisher=[[Jet Propulsion Laboratory]] |id=2015-128 }}</ref>

In September–October 2016, Spitzer was used to discover five of a total of seven known planets around the star [[TRAPPIST-1]], all of which are approximately Earth-sized and likely rocky.<ref name="nasa20170222">{{Cite press release |last1=Chou |first1=Felicia |last2=Potter |first2=Sean |last3=Landau |first3=Elizabeth |date=22 February 2017 |title=NASA Telescope Reveals Largest Batch of Earth-Size, Habitable-Zone Planets Around Single Star |url=https://www.nasa.gov/news-release/nasa-telescope-reveals-largest-batch-of-earth-size-habitable-zone-planets-around-single-star/ |url-status=live |archive-url=https://web.archive.org/web/20240216061923/https://www.nasa.gov/news-release/nasa-telescope-reveals-largest-batch-of-earth-size-habitable-zone-planets-around-single-star/ |archive-date=16 February 2024 |access-date=3 March 2017 |publisher=[[NASA]] |id=17-015 }}</ref><ref name="Gillion2017f1">{{Cite journal |last=Gillon |first=Michaël |display-authors=etal |date=23 February 2017 |title=Figure 1: The TRAPPIST-1 system as seen by Spitzer |journal=[[Nature (journal)|Nature]] |volume=542 |issue=7642 |pages=456–460 |arxiv=1703.01424 |bibcode=2017Natur.542..456G |doi=10.1038/nature21360 |pmc=5330437 |pmid=28230125 }}</ref> Three of the discovered planets are located in the [[habitable zone]], which means they are capable of supporting [[liquid water]] given sufficient parameters.<ref name="kopparapu-2013">{{cite journal |title=A revised estimate of the occurrence rate of terrestrial planets in the habitable zones around kepler m-dwarfs |journal=The Astrophysical Journal Letters |first=Ravi Kumar |last=Kopparapu |volume=767 |issue=1 |pages=L8 |date=25 March 2013 |doi=10.1088/2041-8205/767/1/L8 |bibcode=2013ApJ...767L...8K |arxiv=1303.2649|s2cid=119103101 }}</ref> Using the [[transit method]], Spitzer helped measure the sizes of the seven planets and estimate the mass and density of the inner six. Further observations will help determine if there is liquid water on any of the planets.<ref name="nasa20170222"/>

== See also ==
{{Portal|Astronomy}}
* [[Herschel Space Observatory]] (2009–2013)
* [[Infrared astronomy]]
* [[List of deep fields]]
* [[List of space telescopes]]
* [[List of largest infrared telescopes]]

== References ==
{{Reflist}}

== Further reading ==

* {{Cite web |date=2020-04-14 |title=A Spitzer retrospective |url=https://www.nature.com/collections/cabbfadjgg |access-date= |website=Nature |language=en}}

== External links ==
*{{Commons category-inline|Spitzer Space Telescope}}
* [http://www.nasa.gov/spitzer Spitzer Space Telescope] at NASA.gov
* [http://www.spitzer.caltech.edu/ Spitzer Space Telescope] at Caltech.edu
* [https://web.archive.org/web/20100620093422/http://solarsystem.nasa.gov/missions/profile.cfm?MCode=Spitzer Spitzer Space Telescope] by NASA's Solar System Exploration
* [http://www.alienearths.org/glimpse/ GLIMPSE/MIPSGAL image viewer] at Alienearths.org
* [http://www.bridgingthegaps.ie/2019/07/spitzer-space-telescope-discovering-more-things-in-the-heavens-with-nasas-spitzer-project-scientist-michael-werner/ " Spitzer Space Telescope: Discovering "More Things in the Heavens" with NASA's Spitzer Project Scientist Michael Werner"], 'Bridging the Gaps: A Portal for Curious Minds', 2019

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