Description

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. [MIT 150 Exhibition label text]