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STEREO

Adapted from Wikipedia · Adventurer experience

A colorful image of the Sun showing its hot atmosphere, taken by NASA's STEREO spacecraft.

STEREO

The STEREO (Solar TErrestrial RElations Observatory) was a special project by NASA to watch the Sun closely. It used two almost identical spacecraft called STEREO-A and STEREO-B. These spacecraft were sent into space in 2006. They moved around the Sun in ways that let them see the Sun from different places. This helped scientists make special 3D pictures of the Sun and its big bursts of energy, called coronal mass ejections.

Because of this special way of moving, the two spacecraft could watch solar storms and other Sun activities from different angles. This helped us learn more about how the Sun behaves and how it can affect Earth.

Sadly, in 2014, we lost touch with STEREO-B. We tried to fix the problem, but we could not get it working again.

Mission profile

The two STEREO spacecraft were launched on October 26, 2006, from Cape Canaveral Air Force Station in Florida. They used the Moon's gravity to move into orbits around the Sun. One spacecraft, called STEREO-A, moved ahead of Earth, while the other, STEREO-B, fell behind.

Over time, the two spacecraft moved farther apart from each other. They were exactly on opposite sides of the Sun in February 2011. This allowed scientists to see the entire Sun at once for the first time. In 2014, contact was lost with STEREO-B, but NASA was able to reconnect in 2016. Efforts to fully recover the spacecraft were stopped in 2018.

Mission benefits

STEREO spacecraft in Delta II fairing

The STEREO mission gave us special 3D images of the Sun. The two spacecraft were at different places around the Sun, so they could see parts of the Sun that we cannot see from Earth. This helped scientists watch the far side of the Sun directly.

These spacecraft helped us learn more about big bursts of solar material. These bursts can affect our communications, power grids, and satellites on Earth. Before STEREO, it was hard to see these bursts when they happened on the far side of the Sun. With STEREO, scientists can now watch the whole Sun all the time, which helps them give better warnings about possible problems.

STEREO also helped scientists study stars and discover new ones that change in brightness.

Science instrumentation

Instrument locations on STEREO

Each spacecraft has special cameras and tools to study the Sun. One set of tools, called SECCHI, has five cameras that take pictures of the Sun and its outer atmosphere. These cameras help scientists watch big bursts of solar material moving toward Earth.

Other tools measure tiny particles and radio waves from the Sun. This gives us more information about space weather and how it affects our planet.

Spacecraft subsystems

Each STEREO spacecraft weighed 547 kilograms when empty and 619 kilograms when launched. When folded up for launch, they were small, about 2 meters long, 1.2 meters wide, and 1.1 meters high. After unfolding, they grew larger, especially the solar panels, which stretched out to about 6.5 meters wide. Fully deployed, including all instruments, they measured roughly 7.5 meters long, 8.7 meters wide, and 5.9 meters high. The solar panels provided power for the spacecraft.

The spacecraft stayed steady using special tools that tracked their position in space. They had tiny sensors to notice any changes in direction and a star tracker to know where they were pointing. Inside each spacecraft was a special computer that helped control and send data back to Earth. These computers were built to work well in space. They also had memory to store pictures and information from their instruments until they could send them back home.

Images

A NASA rocket carrying the STEREO spacecraft launches into space from Cape Canaveral, providing scientists with important data about the Sun and space weather.
The STEREO observatories, two spacecraft prepared for launch to study the Sun and solar wind from different angles, improving our understanding of space weather.
A view of the sun's South Pole showing solar activity and material erupting from the surface.
A 3D image of the Sun captured by NASA satellites, showing its bright surface and solar activity.
A 3D animated view of the Sun captured by NASA’s STEREO spacecraft, showing solar activity from space.
Astronomical image of the planet Jupiter taken by NASA's STEREO spacecraft, showing the planet as seen from space.
A stunning image of the far side of the Sun captured by NASA spacecraft, showing solar activity and patterns in space.
Animation showing the paths of spacecraft STEREO A and B as they orbit the Sun from 2006 to 2020, with Earth also visible.
Animation showing the paths of NASA’s STEREO spacecraft as they travel around the Sun and Earth.
An animated view of the Sun’s surface captured by NASA satellites, showing solar activity in ultraviolet light.

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This article is a child-friendly adaptation of the Wikipedia article on STEREO, available under CC BY-SA 4.0.

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