# Planck > former ESA space observatory **Wikidata**: [Q725309](https://www.wikidata.org/wiki/Q725309) **Wikipedia**: [English](https://en.wikipedia.org/wiki/Planck_(spacecraft)) **Source**: https://4ort.xyz/entity/planck ## Summary Planck was a former European Space Agency (ESA) space observatory and space telescope designed to study the universe. Launched in 2009, it operated in a halo orbit around the Sun-Earth L2 point before retiring in 2013. The satellite was a cosmic microwave background experiment named after the physicist Max Planck. ## Key Facts * **Classification:** Space telescope, cosmic microwave background experiment, and artificial satellite of the Sun (former entity). * **Operator:** European Space Agency (ESA). * **Launch Date:** May 14, 2009 (13:12:02) via an Ariane 5 ECA rocket (Flight V188) from ELA-3. * **Service Entry:** August 13, 2009. * **Retirement:** October 23, 2013 (12:10:27). * **Orbit:** Heliocentric orbit; specifically positioned in a halo orbit at the L2 Earth-Sun Lagrangian point. * **Mass:** 1,950 kg (launch weight). * **Dimensions:** 4.20 metres in height and 4.22 metres in diameter. * **Power:** Powered by spacecraft solar arrays (13 m²) and lithium-ion batteries. * **Manufacturers:** Alcatel Space (general contractor) and Alenia Spazio (subcontractor). * **Namesakes:** Also known as COBRAS/SAMBA (Cosmic Background Radiation Anisotropy Satellite/Satellite for Measurement of Background Anisotropies) and Planck Surveyor. ## FAQs ### Q: When was the Planck satellite launched and how long did it operate? A: Planck was launched on May 14, 2009, and began service on August 13, 2009. It was retired on October 23, 2013, operating for just over four years. ### Q: Where was the Planck telescope located during its mission? A: The observatory operated in a halo orbit around the L2 Earth-Sun Lagrangian point, a gravitationally stable point in space ideal for deep-space observation. ### Q: Who built and operated the Planck satellite? A: The European Space Agency (ESA) operated the satellite. It was built by Alcatel Space as the general contractor and Alenia Spazio as the subcontractor. ### Q: What launch vehicle was used for Planck? A: Planck was launched aboard an Ariane 5 ECA rocket (flight V188), sharing the ride with the Herschel Space Observatory. ## Why It Matters The Planck satellite represents a significant milestone in space-based astronomy and the study of cosmic origins. As a major ESA science mission, it was designated as a "cosmic microwave background experiment," indicating its primary role in investigating the residual radiation from the Big Bang to understand the universe's formation and structure. Technically, the mission demonstrated the capabilities of deep-space observation from the L2 Lagrangian point, a location that requires precise orbital mechanics and reliable long-term hardware operation. The satellite's construction involved major European aerospace firms, marking it as one of ESA's significant large-scale astronomy projects (noted in sources as the agency's largest-ever contract awarded for astronomy satellites at the time). Its successful launch alongside the Herschel Space Observatory highlighted the efficiency of dual-payload deployment for heavy space telescopes. ## Notable For * **Specific Mission Type:** Classified primarily as a cosmic microwave background experiment. * **Strategic Location:** Operating at the L2 Earth-Sun Lagrangian point, avoiding Earth's thermal and radio interference. * **Naming:** Named after Max Planck, the originator of quantum theory. * **Dual Launch:** Launched on the same rocket (Ariane 5 ECA) as the Herschel Space Observatory. * **Acronyms:** Originally known by the acronyms COBRAS and SAMBA before being renamed Planck. ## Body ### Mission Timeline and Launch Planck was launched on May 14, 2009, at 13:12:02 UTC from the ELA-3 launch complex. The launch vehicle was an Ariane 5 ECA (designated V188), which also carried the Herschel Space Observatory. Following launch, the satellite entered its service phase on August 13, 2009. The mission concluded with its service retirement on October 23, 2013, at 12:10:27 UTC, after which the final command was sent to the telescope. ### Technical Specifications The satellite had a launch mass of 1,950 kilograms. Structurally, the observatory measured 4.20 metres in height and 4.22 metres in diameter. To maintain power during its mission, Planck utilized spacecraft solar arrays with an area of 13 square metres, supplemented by lithium-ion batteries. ### Orbital Characteristics Unlike satellites orbiting Earth, Planck was an artificial satellite of the Sun. It was inserted into a halo orbit around the L2 Earth-Sun Lagrangian point, a position approximately 1.5 million kilometers from Earth. This orbit allows for a stable thermal environment and continuous observation of deep space. ### Development and Contractors The European Space Agency (ESA) oversaw the project. The prime contract for building the satellite was awarded to Alcatel Space (acting as the general contractor), with Alenia Spazio serving as a subcontractor. The mission was also identified by the identifiers COSPAR 2009-026B and NSSDCA 2009-026B. ## References 1. [Source](https://sci.esa.int/web/planck/-/27524-esa-announces-signature-of-its-largest-ever-contract-awarded-to-build-astronomy-satellites) 2. [Source](https://github.com/JohnMarkOckerbloom/ftl/blob/master/data/wikimap) 3. Jonathan's Space Report 4. [Source](https://www.esa.int/Science_Exploration/Space_Science/Planck/Vital_stats) 5. [Source](https://space.skyrocket.de/doc_sdat/planck.htm) 6. [Source](https://sci.esa.int/web/herschel/-/47356-fact-sheet) 7. Freebase Data Dumps. 2013 8. [Source](https://sci.esa.int/web/planck/-/45543-planck-first-light-yields-promising-results) 9. [Source](http://www.esa.int/Science_Exploration/Space_Science/Planck/Last_command_sent_to_ESA_s_Planck_space_telescope) 10. [Source](http://web.archive.org/web/20150919140130/http://www.arianespace.com/news-mission-update/2009/587.asp) 11. National Library of Israel 12. [OpenAlex](https://docs.openalex.org/download-snapshot/snapshot-data-format)