A Nuclear-Powered Space Mission | Mission Saturn

NARRATOR: Way out into space, the sun's energy-giving rays grow weaker. Solar panels would be little use to Cassini passing distant planets. It needs a far longer lasting source of power: the radioactive power of plutonium-238. In Idaho Falls, behind high level security, the United States Department of Energy harnesses this prized source. The Cassini mission required more nuclear power than any other mission in NASA's history.

NARRATOR: Three heavily shielded thermo-electric generators transformed the heat of radioactive decay into electrical power. They hold iridium-coated plutonium pellets, lasting for decades, but potentially deadly to life. That energy source is what keeps Cassini's cameras taking pictures and powers its radio messages back to Earth. It runs all the devices on the spacecraft, plus the residual heat is funneled into the spacecraft, and it keeps all the instruments warm and in their proper operating range.

NARRATOR: But how do you stay warm when outside temperatures are dropping to minus 364 degrees Fahrenheit? You wrap up in a blanket. In this room at NASA's Jet Propulsion Lab, there is over $1 million worth of them.

MARK DURAN: This is the fabric we use to shield Cassini and protect it against the environmental fluxes of space.

NARRATOR: More than 20 layers of specialized fabric protect Cassini. Not real gold, but colored, aluminized materials. $60,000 worth. Cassini was one of the most challenging spacecrafts to even undertake. It was menacing to think that we had to develop shielding for this entire spacecraft.

NARRATOR: It's taken decades of dreaming, designing, building, and testing. Now, the mission is ready to go.