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https://web.archive.org/web/20161124065046/http://www.losangeles.af.mil/About-Us/Fact-Sheets/Article/343725/infrared-satellites

https://www.losangeles.spaceforce.mil/About-Us/Fact-Sheets/Display/Article/343725/infrared-satellites/

https://www.losangeles.spaceforce.mil/About-Us/Fact-Sheets/Display/Article/734550/space-based-infrared-system-sbirs/

https://news.northropgrumman.com/news/releases/northrop-grumman-delivers-sbirs-geo-1-payload-to-lockheed-martin

https://news.northropgrumman.com/news/releases/northrop-grumman-delivers-sbirs-geo-2-payload-to-lockheed-martin

https://news.northropgrumman.com/news/releases/northrop-grumman-awarded-master-ground-processing-contract

https://m.aviationweek.com/defense-space/space/exclusive-look-sbirs-its-capabilities

https://www.northropgrumman.com/space/space-based-infrared-system-sbirs/

https://nsarchive2.gwu.edu/NSAEBB/NSAEBB235/new54.pdf

https://space.skyrocket.de/doc_sdat/sbirs-geo-1.htm

https://space.skyrocket.de/doc_sdat/trumpet-fo.htm

https://www.popsci.com/zuma-spy-satellite-amateur-astronomer/

https://www.globalsecurity.org/space/library/report/1998/sbirs-brochure/index.html

https://www.globalsecurity.org/space/systems/opir.htm

https://www.globalsecurity.org/space/library/report/1998/sbirs-brochure/part07.htm

https://www.usgs.gov/faqs/what-are-band-designations-landsat-satellites

https://www.lockheedmartin.com/content/dam/lockheed-martin/space/photo/sbirs/SBIRS_Fact_Sheet_(Final).pdf

https://missilethreat.csis.org/defsys/sbirs/

https://missiledefenseadvocacy.org/defense-systems/sbirs-geo-1/

https://sattrackcam.blogspot.com/2014/03/satellites-and-malaysian-airlines.html

https://sattrackcam.blogspot.com/2015/11/satellite-observations-and-russian.html

www.afspc.af.mil/news/story.asp?id=123341934

http://science.dodlive.mil/2011/05/05/modern-missile-defense-sbirs-satellite-set-to-launch/

https://web.archive.org/web/20110507102317/http://science.dodlive.mil/2011/05/05/modern-missile-defense-sbirs-satellite-set-to-launch/

http://www.lockheedmartin.com/us/news/press-releases/2012/june/0605-ss-sbirs.html

https://web.archive.org/web/20120610201602/http://www.lockheedmartin.com/us/news/press-releases/2012/june/0605-ss-sbirs.html

http://fas.org/spp/military/program/warning/sbirs-brochure/part07.htm

https://breakingdefense.com/2021/05/new-sbirs-sat-creates-bridge-to-next-gen-missile-warning/

https://web.archive.org/web/20110623033532/http://science.dodlive.mil/2011/05/05/modern-missile-defense-sbirs-satellite-set-to-launch/

https://nsarchive2.gwu.edu/NSAEBB/NSAEBB235/new54.pdf

https://web.archive.org/web/20160620084551/http://www.nbcnews.com/storyline/russian-plane-crashes-in-the-sinai/satellite-shows-heat-flash-when-russian-metrojet-plane-crashed-no-n456161

https://www.cnn.com/2014/07/17/world/europe/ukraine-malaysia-airlines-crash/index.html

https://spaceflightnow.com/news/n1407/21mh17/