The mission was originally planned for a 2003 launch, but was delayed following the Space Shuttle Columbia disaster. Some other components are also planned to be mounted externally on Columbus on future missions, including the Atomic Clock Ensemble in Space (ACES). Another name for SOLAR may be Solar Monitoring Observatory or SMO.
In 2012, the entire 450-tonne station was rotated so SOLAR could observe a full rotation of the Sun continuously.6 A Solar rotation takes about 24–28 days depending on the latitude.7
SOLAR's mission ended in 2017 with the failure of all but one of its instruments. On the morning of January 28, 2020 SOLAR was removed from FRAM 1 where it rested since it was delivered on STS 122 and strapped to the side of Cygnus NG-12 with the SDS placed on the other side. SOLAR was released from the station on February 3, 2020 and burnt up in the atmosphere over the Pacific Ocean on March 13, 2020 ending the mission which spent a decade photographing the sun.8
SOLAR: three years observing and ready for solar maximum - ESA http://www.esa.int/esaHS/SEMB9XXTVKG_research_0.html ↩
Sun Monitoring on the External Payload Facility of Columbus (Solar) http://santacruzsolarcompanies.com/sun-monitoring-external-payload-facility-columbus-solar/ ↩
"Solar Package on ISS". Belgian User Support and Operation Centre. Retrieved 2007-09-21. http://santacruzsolarcompanies.com/set-solar-instruments-outside-columbus/ ↩
Manise, Nicolas (2000-08-22). "SOVIM (Solar Variability and Irradiance Monitor)". Belgian International Space Station User Support Center. Retrieved 2007-09-21.[permanent dead link] http://columbus.busoc.be/solar/sovim/ ↩
Wienhold, F.G.; et al. (2000). "The solar package on ISS: SOL-ACES". Physics and Chemistry of the Earth, Part C: Solar, Terrestrial & Planetary Science. 25 (5–6): 473–476. Bibcode:2000PCEC...25..473W. doi:10.1016/S1464-1917(00)00060-X. /wiki/Bibcode_(identifier) ↩
International Space Station http://www.esa.int/SPECIALS/Columbus/SEM0D5EQZ9H_0.html ↩
Solar rotation /wiki/Solar_rotation ↩
Clark, Stephen. "Cygnus departs space station, deploys CubeSats – Spaceflight Now". Retrieved 2020-06-12. https://spaceflightnow.com/2020/02/03/cygnus-departs-space-station-deploys-cubesats/ ↩