[3] In addition to its scientific mission, it is a main source of near-real-time solar data for space weather prediction.

Although sometimes described as being at L1, the SOHO spacecraft is not exactly at L1 as this would make communication difficult due to radio interference generated by the Sun, and because this would not be a stable orbit.

In normal operation, the spacecraft transmits a continuous 200 kbit/s data stream of photographs and other measurements via the NASA Deep Space Network of ground stations.

SOHO's data about solar activity are used to predict coronal mass ejection (CME) arrival times at Earth, so electrical grids and satellites can be protected from their damaging effects.

[4] However, ESA and NASA engineers managed to use SOHO's low-gain antennas together with the larger 34 m (112 ft) and 70 m (230 ft) NASA Deep Space Network ground stations and judicious use of SOHO's Solid State Recorder (SSR) to prevent total data loss, with only a slightly reduced data flow every three months.

[6] Expert European Space Agency (ESA) personnel were immediately dispatched from Europe to the United States to direct operations.

SOHO was close to its predicted position, oriented with its side versus the usual front Optical Surface Reflector panel pointing toward the Sun, and was rotating at one revolution every 53 seconds.

After instrument temperatures were downlinked on 9 August 1998, data analysis was performed, and planning for the SOHO recovery began in earnest.

Attitude control was accomplished with manual thruster firings that consumed 7 kg (15 lb) of fuel weekly, while the ESA developed a new gyroless operations mode that was successfully implemented on 1 February 1999.

Approximately one-half of all known comets have been spotted by SOHO, discovered over the last 15 years by over 70 people representing 18 different countries searching through the publicly available SOHO/LASCO images online.

The Max Planck Institute for Solar System Research contributed to SUMER, Large Angle and Spectrometric Coronagraph (LASCO), and CELIAS instruments.

The Institut d'astrophysique spatiale is the principal investigator of GOLF and Extreme ultraviolet Imaging Telescope (EIT), with a strong contribution to SUMER.