STEREO (Solar TErrestrial RElations Observatory) is a 2-year NASA mission employing two nearly identical space-based observatories to provide the very first, 3-D "stereo" images of the sun to study the nature of coronal mass ejections. These powerful solar eruptions are a major source of the magnetic disruptions on Earth and a key component of space weather, which can greatly affect satellite operations, communications, power systems, the lives of humans in space, and global climate.

STEREO is the third mission in NASA's Solar Terrestrial Probes Program. The twin observatories launched aboard a single Boeing Delta II rocket from Cape Canaveral Air Force Station, Fla., on Oct. 25, 2006, at 8:52 p.m. EDT.

STEREO is sponsored by NASA Headquarters' Science Mission Directorate, Washington, D.C. NASA Goddard Space Flight Center's Solar Terrestrial Probes Program Office, in Greenbelt, Md., manages the mission, instruments and science center. The Johns Hopkins University Applied Physics Laboratory (APL), in Laurel, Md., designed and built the spacecraft and will operate the twin observatories for NASA during the mission.