NEI Nuclear Notes

And the winner is…Cassini-Huygens, in triple overtime. The spaceship conceived in 1982 and launched fifteen years later, will crash into Saturn on September 15, after a mission of 19 years and 355 days, powered by the audacity and technical prowess of scientists and engineers from 17 different countries, and 72 pounds of plutonium. The mission was so successful that it was extended three times; it was intended to last only until 2008. Since April, the ship has been continuing to orbit Saturn, swinging through the 1,500-mile gap between the planet and its rings, an area not previously explored. This is a good maneuver for a spaceship nearing the end of its mission, since colliding with a rock could end things early. Cassini will dive a little deeper and plunge toward Saturn’s surface, where it will transmit data until it burns up in the planet’s atmosphere. The radio signal will arrive here early Friday morning, Eastern time. A NASA video explains. In the years since Cassini ...

Did you see the movie The Martian ? The hero, Mark Watney, an astronaut given up for dead by NASA, uses a radioisotope thermoelectric generator (RTG), a sort-of "space battery," to keep warm during his trek across Mars. The movie is science fiction but these devices are real- NASA has been using RTGs to power satellites for nearly forty years , and they've been used on major trips to the moon and other planets. But NASA recently announced plans to use nuclear power in a different way- one that hasn't been fully attempted in fifty years.  The RTGs like Mark Watney’s harness the heat from passive radioactive decay and produce a few hundred watts of electricity, which on Earth would be enough to run a handful of household appliances. But a mission to Mars would require far more power. Now, NASA is working on a reactor that splits atoms, as reactors on Earth do, to make 100 times more electricity than an RTG. The initial plan calls for 40 kilowatts, which on Ear...

Sometimes, irony abounds : When it comes to space travel, plutonium-238 is the perfect fuel: long-lasting and, as I'll explain later, relatively safe. Without it, we have no hope of going much further than Mars, after which it simply becomes too dark to rely on solar panels, the most common alternative power source in space. But the world is rapidly running out of plutonium-238. Where’s the irony? Plutonium-238 is a byproduct of producing plutonium-239, which was used in nuclear weaponry. With the end of the cold war, and the dismantling of much of the nuclear arsenal, there’s no call for plutonium-239. It a case of undoubted progress blocking further progress. Happily, that’s not the end of the story. The government is looking into another way of making plutonium-238. Sarah Zhang at Gizmodo explains the process: The production plan, for now, involves hopping between no fewer than three DOE labs all over the country. Idaho National Laboratory: The precurso...

“If anybody has been harboring doubts about the status of U.S. leadership in space, well, there’s a one-ton, automobile-size piece of American ingenuity, and it’s sitting on the surface of Mars right now.” This statement came from John Holdren , President Obama’s science advisor, this morning following the landing of a 2,000-pound nuclear-powered space rover, Curiosity , on the surface of Mars. This marks the first time that NASA has ever safely landed a human-made object of this size and weight on the surface of Mars, a notable feat in American engineering. Early reports from The New York Times describes the rover’s landing on the Red Planet like a scene in a movie script: As the drama of the landing unfolded, each step proceeded without flaw. The capsule entered the atmosphere at the appointed time, with thrusters guiding it toward the crater. The parachute deployed. Then the rover and rocket stage dropped away from the parachute and began a powered descent toward the surfac...