Image of <i>Voyager</i> Plasma Science Experiment Voyager Plasma Science Experiment
NASA Voyager Plasma Science Experiment, MIT Space Plasma Group, 1977–Present

On December 13, 2010, the Voyager I spacecraft reached the distant point in our solar system where the outward motion of solar wind ceases and the spacecraft is about to enter interstellar space. Voyager II will make a similar transition out of the heliosheath in a few months. They are now the human-made objects farthest away from Earth on the longest exploratory mission in history. Aboard the two spacecraft are five instruments supporting five ongoing experiments. The Plasma Science Experiment (PSE) is the work of the MIT Space Plasma Group founded in the early 1970s by Herbert Bridge and Bruno Rossi. The two PSE instruments (“Plasma” or “Faraday” Cups) were launched in 1977. For more than three decades, these instruments have been sending data back every 160 seconds on this “Grand Tour” of the planets and beyond. The data collected by the plasma cup on solar wind speed, density, temperature, and pressure are available online a few days after they are received by the Space Plasma Group.

On loan from the MIT Kavli Institute for Astrophysics and Space Research.

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  • the incredible creations of the human mind…

    cary hernandez
    15 Feb 11 at 1:20 am
  • It’s really a great project. I wish the team the best of the best of luck for the experimental expected outcomes or device to be working as expected. Keep it up!
    I hope you continue the same progress even better.

    Prakash Shrestha
    15 Feb 11 at 3:23 am
  • I would be interested whether the Voyager I spacecraft still has enough energy to send information back to Earth.

    15 Feb 11 at 6:29 am
  • Let us hope that the spacecraft is not hit by any celestial object.

    15 Feb 11 at 8:13 am
  • I was 16 years old when Voyager 1 was launched…and to think that after 3 decades we are still receiving information from this magnificent project. It’s mind boggling and makes me feel so proud of the efforts of MIT and our Space Program. I am 50 years old now…and my son is a freshman at MIT with a desire to study Aeronautical Engineering. It all just brings tears to my eyes…keep up the great work…forever!

    Joel Santisteban
    15 Feb 11 at 10:13 am