STEREO
Two spacecraft providing stereoscopic views of the Sun.
STEREO (Solar TErrestrial RElations Observatory) is a solar observation mission consisting of two nearly identical spacecraft, STEREO-A and STEREO-B, launched in 2006 into orbits around the Sun that cause them to respectively pull ahead of and fall behind the Earth. This configuration enabled stereoscopic imaging of the Sun and solar phenomena such as coronal mass ejections, providing a three-dimensional view of solar activity.
Quick Facts
- Insignia Caption
- Mission insignia
- Mission Type
- Solar observation
- Operator
- NASA
- Cospar Id
- STEREO-A: 2006-047A / STEREO-B: 2006-047Bn
- Satcat
- STEREO-A: 29510 / STEREO-B: 29511
- Manufacturer
- Johns Hopkins University Applied Physics Laboratory
- Dry Mass
- 547 kg
- Launch Mass
- STEREO-A: 620 kg / STEREO-B: 620 kg
- Dimensions
- 3.75 xx
- Power
- 475 W
Facts from the source article.
Lore & Background
The STEREO spacecraft carry four instrument packages: SECCHI (five cameras for imaging the Sun and corona), IMPACT (for particles and magnetic fields), PLASTIC (for plasma composition), and SWAVES (for radio bursts). On July 23, 2012, STEREO-A was in the path of a Carrington-class coronal mass ejection and collected significant data without being harmed. The mission's primary focus remains solar observation, and while it has contributed to stellar astronomy, specific numbers of discovered eclipsing binaries are not a canonical achievement.
Reader's Guide
STEREO's principal significance lies in its stereoscopic imaging of the Sun, which allowed NASA scientists to directly monitor the far side of the Sun for the first time, rather than inferring activity from Earth-based views. This capability was critical for detecting coronal mass ejections (CMEs)—massive bursts of solar wind and plasma that can disrupt communications, airlines, power grids, and satellites. Before STEREO, far-side sunspots could only be detected via helioseismology, which provided low-resolution maps. The mission's 360° views, combined with Earth-based observatories like the Solar Dynamics Observatory, improved space weather forecasting. STEREO's observations are incorporated into forecasts for airlines, power companies, and satellite operators. The loss of STEREO-B in 2014, after an uncontrolled spin, ended the full stereoscopic capability, but STEREO-A continues to provide data. The mission also contributed to stellar astronomy by discovering eclipsing binaries and studying variable stars.
Did You Know?
- STEREO-A and STEREO-B were launched on a single Delta II rocket on October 26, 2006.
- On February 6, 2011, the two spacecraft were exactly 180° apart, allowing the entire Sun to be seen at once for the first time.
- Contact with STEREO-B was lost on October 1, 2014, after it entered an uncontrolled spin of about 3° per second.
- STEREO-A survived a Carrington-class coronal mass ejection on July 23, 2012, and collected significant data.
More in Missions to the Sun 1-21
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