page_title: Solar and Heliospheric Observatory
hierarchical_section_title: Solar and Heliospheric Observatory
caption_attribution_description: English: NASA Solar and Heliospheric Observatory (SOHO) spacecraft
context_page_description: The Solar and Heliospheric Observatory is a spacecraft built by a European industrial consortium led by Matra Marconi Space that was launched on a Lockheed Martin Atlas II AS launch vehicle on December 2, 1995, to study the Sun. It has also discovered over 3,000 comets. It began normal operations in May 1996. It is a joint project between the European Space Agency and NASA. Originally planned as a two-year mission, SOHO continues to operate after over 25 years in space; the mission has been extended until the end of 2020 with a likely extension until 2022.
  In addition to its scientific mission, it is a main source of near-real-time solar data for space weather prediction. Along with Wind, ACE, and DSCOVR, SOHO is one of four spacecraft in the vicinity of the Earth–Sun L1 point, a point of gravitational balance located approximately 0.99 astronomical units from the Sun and 0.01 AU from the Earth. In addition to its scientific contributions, SOHO is distinguished by being the first three-axis-stabilized spacecraft to use its reaction wheels as a kind of virtual gyroscope; the technique was adopted after an on-board emergency in 1998 that nearly resulted in the loss of the spacecraft.
context_section_description: The Solar and Heliospheric Observatory (SOHO) is a spacecraft built by a European industrial consortium led by Matra Marconi Space (now Airbus Defence and Space) that was launched on a Lockheed Martin Atlas II AS launch vehicle on December 2, 1995, to study the Sun. It has also discovered over 3,000 comets. It began normal operations in May 1996. It is a joint project between the European Space Agency (ESA) and NASA. Originally planned as a two-year mission, SOHO continues to operate after over 25 years in space; the mission has been extended until the end of 2020 with a likely extension until 2022.
  In addition to its scientific mission, it is a main source of near-real-time solar data for space weather prediction. Along with Wind, ACE, and DSCOVR, SOHO is one of four spacecraft in the vicinity of the Earth–Sun L1 point, a point of gravitational balance located approximately 0.99 astronomical units (AU) from the Sun and 0.01 AU from the Earth. In addition to its scientific contributions, SOHO is distinguished by being the first three-axis-stabilized spacecraft to use its reaction wheels as a kind of virtual gyroscope; the technique was adopted after an on-board emergency in 1998 that nearly resulted in the loss of the spacecraft.
caption: Artist's concept of SOHO
exif: {}