Cassini Spacecraft at Saturn Has Minor Short Circuit, NASA Says

Artist concept of Cassini at Saturn.
Artist's concept of NASA's Cassini spacecraft at Saturn. (Image credit: NASA/JPL)

NASA engineers shut down part of the Cassini spacecraft at Saturn after an apparent short circuit in one of the 14-year-old probe's science instruments.

Cassini mission managers decided to stop using the Saturn probe's plasma spectrometer on Tuesday (June 14) following a series of unexpected voltage readings, NASA officials said Wednesday.

The problem began on May 1, when an unexpected voltage shift was detected, officials at NASA's Jet Propulsion Laboratory in Pasadena, Calif., said in a statement. That suggested a short circuit was at work, but when another event occured on June 11 it sugggested a second short circuit had occurred, they added.

At all times Cassini's instruments and engineering systems continued working normally. [Cassini Photos: Saturn's Rings and Moons]

"Analysis of telemetry data from the spacecraft by the engineering team pointed to the Cassini plasma spectrometer instrument as the cause of the voltage shifts," JPL officials said, adding that the instrument has an extra set of capacitors in its power lines to reduce signal noise. "The concern was that one or more of these capacitors may have short-circuited, which would cause the voltage to shift and explain the observed changes. Although the instrument was operating properly, engineers decided to turn it off as a precaution until the events could be better understood."

The plasma spectrometer is one of 12 instruments the Cassini uses to study Saturn. The instrument is used to measure the energy and electrical charge of particles around Saturn.

While Cassini's plasma spectrometer is offline, its 11 other instruments are expected to continue working normally.

"The plan is to resume normal plasma spectrometer operations after further analysis is completed to understand the cause of the issue better," JPL officials said.

NASA launched the Cassini spacecraft toward Saturn in 1997 and it arrived at the ringed planet in 2004. The orbiter has been circling the planet to study its rings and moons ever since. Cassini also carried the European Huygens lander to Saturn. The lander touched down on Titan, Saturn's largest moon, in 2005. 

Cassini's mission was originally slated to end in 2008, but NASA has extended the Saturn flight twice, most recently until 2017. The Cassini mission is a cooperative effort by NASA, the European Space Agency and the Italian space agency.

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Tariq Malik

Tariq is the Editor-in-Chief of and joined the team in 2001, first as an intern and staff writer, and later as an editor. He covers human spaceflight, exploration and space science, as well as skywatching and entertainment. He became's Managing Editor in 2009 and Editor-in-Chief in 2019. Before joining, Tariq was a staff reporter for The Los Angeles Times covering education and city beats in La Habra, Fullerton and Huntington Beach. In October 2022, Tariq received the Harry Kolcum Award for excellence in space reporting from the National Space Club Florida Committee. He is also an Eagle Scout (yes, he has the Space Exploration merit badge) and went to Space Camp four times as a kid and a fifth time as an adult. He has journalism degrees from the University of Southern California and New York University. You can find Tariq at and as the co-host to the This Week In Space podcast with space historian Rod Pyle on the TWiT network. To see his latest project, you can follow Tariq on Twitter @tariqjmalik.