ISEE-3 comes to visit Earth

April 21, 2014
Artist's concept image of ISEE-3 (ICE) spacecraft. Credit: NASA

(Phys.org) —It launched in 1978. It was the first satellite to study the constant flow of solar wind streaming toward Earth from a stable orbit point between our planet and the sun known as the Lagrangian 1, or L1. Monitoring that wind helped scientists better understand the interconnected sun-Earth system, which at its most turbulent can affect satellites around Earth.

In 1984, it was given a new mission and called the International Cometary Explorer. In September 1985, it passed directly through the tail of Comet Giacobini-Zinner, making it the first spacecraft to encounter and gather data from a comet. It also went on to fly by Comet Halley in March 1986. From 1991 until 1997, when it was too far away for reliable communications, this satellite continued to investigate the sun. Now it's coming home to visit - making its to Earth in August 2014 before it heads back out to .

This is the story of NASA's and the European Space Agency's International Sun-Earth Explorer (ISEE-3). Beacon signals from the spacecraft's communications system demonstrate that it is still operating, but scientists and engineers don't know how well. This beacon is also how they know the spacecraft is still following the same orbit around the sun, moving slightly faster than Earth.

This video is not supported by your browser at this time.
Top-down view of the orbit of ISEE-3 (ICE) relative to the inner solar system. We see the orbit alternates with the spacecraft occasionally closer, then further from the Sun than Earth. Credit: NASA's Scientific Visualization Studio

The ISEE-3 mission was state-of-the-art when it launched. It used an S-band frequency, part of the microwave band of electromagnetic waves, for communication. At the time, this frequency was reserved for government air and space communications. Today, the S-band once used for ISEE-3 is outmoded. Solar wind data that ISEE-3 gathered at the rate of once every 40 minutes has been replaced by spacecraft with instruments that are 10,000 times faster.

ISEE-3 opened new pathways for scientific exploration. Although overtaken by advances in technology, ISEE-3 remains a testament to the scientists and engineers who conceived, launched and managed this versatile, old .

This video is not supported by your browser at this time.
An oblique view of the orbit of ISEE-3 (ICE) relative to the inner planets. Close-up view of the Earth flyby in mid-2014. Credit: NASA's Scientific Visualization Studio

Today, some citizen scientists are investigating whether it would be feasible to communicate with ISEE-3 for the first time in almost two decades in order to send commands to return it to L1. A daunting prospect after all this time with NASA's old friend.

Explore further: Electron beams and radio signals from the surface of the Sun

Related Stories

Electron beams and radio signals from the surface of the Sun

November 15, 2013

The sun emits light, but it also emits particle beams. A scientist at the Swedish Insitute of Space Physics (IRF) in Uppsala has revealed how these beams generate radio waves. These radio waves can tell us about the outer ...

Image: Rosetta's comet

January 21, 2014

(Phys.org) —ESA's Rosetta spacecraft woke up 20 January, after 31 months in deep space hibernation, to catch up with comet 67P/Churyumov–Gerasimenko.

NEOWISE spies its first comet

March 3, 2014

(Phys.org) —NASA's Near-Earth Object Wide-field Infrared Survey Explorer (NEOWISE) spacecraft has spotted a never-before-seen comet—its first such discovery since coming out of hibernation late last year.

Recommended for you

Interstellar seeds could create oases of life

August 27, 2015

We only have one example of a planet with life: Earth. But within the next generation, it should become possible to detect signs of life on planets orbiting distant stars. If we find alien life, new questions will arise. ...

Dawn spacecraft sends sharper scenes from Ceres

August 25, 2015

The closest-yet views of Ceres, delivered by NASA's Dawn spacecraft, show the small world's features in unprecedented detail, including Ceres' tall, conical mountain; crater formation features and narrow, braided fractures.

0 comments

Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.