Lunar and Planetary Institute
Lunar and Planetary Institute



Artist’s depiction of the deployment of the STEREO solar panels. Courtesy Johns Hopkins University Applied Physics Laboratory.NASA's First 3-D Solar Imaging Mission Soars into Space

October 26, 2006

NASA’s twin Solar Terrestrial Relations Observatories mission, known as STEREO, successfully launched October 25, 2006, at 8:52 p.m. EDT from Cape Canaveral Air Force Station, Florida.

STEREO’s nearly identical twin, golf-cart-sized spacecraft will make observations to help researchers construct the first-ever three-dimensional views of the Sun. The images will show the star’s stormy environment and its effects on the inner solar system, vital data for understanding how the Sun creates space weather.

The two observatories were launched on a Delta II rocket. After receiving the first signal from the spacecraft approximately 63 minutes after launch, mission control personnel confirmed that each observatory’s solar arrays successfully deployed and were providing power. NASA’s Deep Space Network antennas in Canberra, Australia received the initial radio signals.

After about two months, STEREO’s orbits will be synchronized to encounter the Moon. The “A” observatory will use the Moon’s gravity to redirect it to an orbit “ahead” of Earth. The “B” observatory will encounter the Moon again for a second swing-by about one month later to redirect its position “behind” Earth. STEREO is the first NASA mission to use separate lunar swing-bys to place two observatories into vastly different orbits around the Sun.

Just as the slight offset between human eyes provides depth perception, this placement will allow the STEREO observatories to obtain three-dimensional images of the Sun. The arrangement also allows the two spacecraft to take local particle and magnetic field measurements of the solar wind as it flows by.

During the observatories’ two-year mission, they will explore the origin, evolution, and interplanetary consequences of coronal mass ejections, some of the most violent explosions in our solar system. These billion-ton eruptions can produce spectacular aurora and disrupt satellites, radio communications, and Earth’s power systems. Better prediction of solar eruptions provides more warning time for satellite and power grid operators to put their assets into a safe mode to weather the storm. A better understanding of the nature of these events will help engineers build better and more resilient systems.

For more information:

NASA Mission News


Artist’s depiction of the deployment of the STEREO solar panels. Courtesy Johns Hopkins University Applied Physics Laboratory.

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Last updated January 30, 2008