The NASA probe whose 20-year journey will end with a crash into Saturn got its power from Dayton

Credit: DaytonDailyNews

A 20-year mission to Saturn by the Cassini space probe will end on Sept. 15 when the scientific spacecraft flies itself into our solar system’s second largest planet.

The power source for this long and now crash-ending flight was assembled in Dayton.

University of Dayton Research Institute scientists and engineers Chadwick Barklay, left, Daniel Kramer and Richard Harris observe a Multi-Mission Radioisotope Thermoelectric Generator that converts the heat from the natural decay of a plutonium-238 dioxide to electricity through solid-state thermoelectric couples. Their laboratory is testing two of the MMRTG units that are cousins of the of Cassini mission power unit assembled in Dayton. TY GREENLEES / STAFF

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Power for Cassini is provided by a radioisotope thermoelectric generators (RTG). Think: nuclear power plant in a shoebox.

The RTG design on Cassini was assembled by a team at the Mound Laboratories in Miamisburg. University of Dayton distinguished research scientist Chadwick Barklay, Ph.D., was part of the assembly and testing team for Cassini mission in 1997 and describes it this way: “We drove them to the Kennedy Space Center with a Department of Energy caravan. The units were mated up with Cassini in NASA’s payload hazardous storage facility. We got to see them power up the spacecraft with the RTG for the first time.”

Barklay’s teammates from Mound Laboratories also assembled RTGs for other NASA mission including Ulysses, Galileo, and New Horizons . Barklay continues to work with others at UDRI on future designs of RTGs for use in space flight.

The 204-foot Titan IVB rocket on display in the National Museum of the U.S. Air Force fourth building.  The Titan IVB could launch payloads as heavy as 23.9 tons and was the largest and most powerful expendable rocket in the Air Force inventory.  TY GREENLEES / STAFF

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Another Titan in this story involves the rocket that launched the Cassini-Huygens mission back in 1997. The heavy lift Lockheed Martin Titan IVB rocket boosted the spacecraft out of earth’s gravity and was the only use of the Titan IVB outside of the Department of Defense.

The only complete Titan IVB rocket in existance today is on display at the National Museum of the United States Air Force in Dayton.

So, why end now? NASA explains:

“By 2017, Cassini will have spent 13 years in orbit around Saturn, following seven years of ‘cruise’ on its way outward from Earth. The spacecraft is beginning to run low on rocket fuel. If left unchecked, this situation would eventually prevent mission operators from controlling the course of the spacecraft.

“Two moons of Saturn, Enceladus and Titan, have captured news headlines over the past decade as Cassini data revealed the moons’ potential to contain habitable – or at least ‘pre-biotic’ – environments.

“In order to avoid the unlikely possibility of Cassini someday colliding with one of these moons and contaminating them with any hardy Earth microbes that might have survived on the spacecraft, NASA has chosen to safely dispose of the spacecraft in the atmosphere of Saturn.”

The mission recorded a wealth of images and data about the giant ringed planet that will take years to analyze and decipher. Discoveries including ring formation, icy plumes emanating from an underground ocean on the Saturnian moon Enceladus, and Titan to be Earth-like in some ways with rain, rivers, lakes and seas.

Launch of the Cassini-Huygens mission to Saturn atop a Titan IVB Centaur launch vehicle in 1997.  NASA/JPL

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With giant Saturn hanging in the blackness and sheltering Cassini from the sun's blinding glare, the spacecraft viewed the rings as never before, revealing previously unknown faint rings and even glimpsing its home world.  This marvelous panoramic view was created by combining a total of 165 images taken by the Cassini wide-angle camera over nearly three hours on Sept. 15, 2006. The full mosaic consists of three rows of nine wide-angle camera footprints; only a portion of the full mosaic is shown here. Color in the view was created by digitally compositing ultraviolet, infrared and clear filter images and was then adjusted to resemble natural color.  NASA/JPL

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