The Plutonium Pathway followed by Pu-238 used in the nuclear batteries that fuel NASA rovers.
The plutonium-238 that powers NASAs rovers on Mars crisscrosses the United States first on a tour of national laboratories.
Department of Energy officials outlined the path and process of manufacturing the Pu-238 for the Perseverance Rover that launched in July and is already about two-thirds of the way to the Red Planet.
Perseverance's nuclear heart completed its own journey of seven years and nearly 5,000 miles before finally meeting up with the rover at Kennedy Space Center in Florida, said Matt Dozier, the host of DOEs Direct Current podcast.
NASA uses a solid-state nuclear battery, called a Multi-Mission Radioisotope Thermoelectric Generator, instead of, say, solar arrays, so the rover can keep operating during dust storms and the Martian night. With a halflife of 90 years, Pu-238 can keep a craft powered for decades.
Whats the secret to their longevity? Dozier asks. Its not turmeric, or acai berries, or wheat germthe Mars rovers, and dozens of other NASA missions, run on a diet of pure plutonium-238.
The $75 million MMRTG produces about 110 watts of electricity from the heat of decaying PU-238.
Dozier interviewed DOE officials tasked with processing and securing the dangerous isotope during each step of its manufacture:
1 Idaho National Laboratory: The fuel begins its journey as neptunium-237, a by-product of nuclear reactors thats stored at Idaho National Laboratories. The Oak Ridge National Lab essentially calls up the Idaho National Lab and phones in a shipment, let's say, for neptunium, said Robert Wham, program manager for the Pu-238 Supply Program at Oak Ridge. We get neptunium on a just-in-time basis; its shipped to us, and then we do the chemical processing here.
2 Oak Ridge National Laboratory: Oak Ridge mixes the Np-237 with aluminum and bombards it with radiation in a reactor for 50 to 60 days. Some of the Np-237 turns into Pu-238, which Oak Ridge technicians separate, collecting plutonium as a powder. Oak Ridge also builds an iridium cladding that should keep the plutonium contained.
Oak Ridge National Laboratorys Chris Jensen peers through 4.5 feet of alternating lead and glass ... [+] layers into a hot cell where plutonium is separated from neptunium for NASA rover power systems.
One of the things that we worry about is that if there's an accident either during launch or shortly after launch, that when these generators come back to Earth, and they'll crash into Earth at very high velocities, very high speeds, said Easo George, an alloys expert who serves as the governors chair at the Department of Energys Oak Ridge National Laboratory and the University of Tennessee. And we want to make sure that ifsuch a very low-probability eventbut if something like that were to happen, that the iridium would contain the plutonium fuel and prevent it contaminating areas around where it strikes.
3 Los Alamos National Laboratory: The Pu-238 then heads 1,400 miles west to Los Alamos National Laboratory, where technicians press it into ceramic pellets, heat it in a kiln, encapsulate it in the iridium cladding, and test it to NASAs standards. At that point:
It's silver in color, it's kind of round, about an inch tall, and it's fairly heavy because it is a dense material, said Jackie Lopez-Barlow, LANLs radioisotope power systems program manager. So if you were to hold it in the palm of your hand, it would take up about half the size of your palm of your hand. You wouldn't want to hold it in your hand, because it's extremely hot, about 400 Celsius.
4 Idaho National Laboratory: The fuel then hits the road again, returning to Idaho where the fuel clads will be inserted into nuclear-power systems built by Teledyne Energy Systems Incorporated and Aerojet Rocketdyne. INL performs more testing on the whole unit and then has to get the power system to Florida in time for NASAs launch window, when Earth and Mars are closest in their orbits, an event that occurs once every 26 months.
5 Kennedy Space Center: The 2,500-mile trip from Idaho to Florida happens via semi-trailer, supervised by the Department of Energys National Nuclear Security Administration.
So those guys come up to our laboratory with their tractor, said Kelly Lively, INLs department manager for radioisotope power systems, and we would already have our power system inserted into a steel cask inside our transportation trailer which is a 52 foot long semi-trailer.
You know it's a nuclear payload being transported across several state lines, so it's kind of a sobering moment.
6 Cape Canaveral Air Force Station: After the power unit is married to the rover at Kennedy, it takes a relatively short trip to the cape to enter the nose cone ofin Perseverences casean Atlas V rocket.
The Pu-238 is not weapons-grade, but that doesnt mean the Martians couldnt turn it to nefarious ends. It is still a proliferation risk, according to the World Nuclear Association:
In practical terms, there are two different kinds of plutonium to be considered: reactor-grade and weapons-grade.... The two kinds differ in their isotopic composition but must both be regarded as a potential proliferation risk, and managed accordingly.
Marvin the Martian holding an Illudium PU-36 Explosive Space Modulator. (Photo by Albert L. ... [+] Ortega/Getty Images)
More:
NASAs Plutonium Tours U.S. Before Heading To Mars - Forbes
- 2D Laser Profiling Scanner for Detecting Targets - November 8th, 2009 [November 8th, 2009]
- NASA Energy Concept Could Harness the Power of Ocean Waves - November 8th, 2009 [November 8th, 2009]
- Data Acquisition Modules - November 8th, 2009 [November 8th, 2009]
- Dr. Scott Barthelmy, Research Scientist, Laboratory for High Energy Astrophysics, Goddard Space Flight Center, Greenbelt, MD - November 8th, 2009 [November 8th, 2009]
- Laser Tracker Ensures Accurate Alignment of Ares I Components - November 8th, 2009 [November 8th, 2009]
- Dual Cryogenic Capacitive Density Sensor - November 8th, 2009 [November 8th, 2009]
- Advanced Technologies Will Help Hubble Yield More Remarkable Discoveries - November 8th, 2009 [November 8th, 2009]
- Dr. Gerard Holzmann, Senior Research Scientist at the Laboratory for Reliable Software, NASA’s Jet Propulsion Laboratory - November 8th, 2009 [November 8th, 2009]
- NASA Research Will Help Aircraft Avoid Ocean Storms and Turbulence - November 8th, 2009 [November 8th, 2009]
- NASA Awards 2008 Software of the Year - November 8th, 2009 [November 8th, 2009]
- Here Come The Tricorders - Update - November 8th, 2009 [November 8th, 2009]
- China's View on Space - November 8th, 2009 [November 8th, 2009]
- Milsat Coordination and Tracking Issues - November 8th, 2009 [November 8th, 2009]
- Trash Talking and End Runs at NASA HQ - November 8th, 2009 [November 8th, 2009]
- Ares 1-Y is Toast - November 8th, 2009 [November 8th, 2009]
- Beyond Augustine - November 8th, 2009 [November 8th, 2009]
- Analyzing LCROSS' Plume - November 8th, 2009 [November 8th, 2009]
- Live Event: NASA-Sponsored Power Beaming Challenge - November 8th, 2009 [November 8th, 2009]
- JSC Wants To Build a Replicator - November 8th, 2009 [November 8th, 2009]
- USA: Looking For Ways To Hang On - November 8th, 2009 [November 8th, 2009]
- Lunar Lander Challenge Prizes Awarded - November 8th, 2009 [November 8th, 2009]
- Senate Votes To Restore NASA Budget Cuts - November 8th, 2009 [November 8th, 2009]
- New FAA Regs for Commercial Reentry - November 8th, 2009 [November 8th, 2009]
- TEDxNASA: An Invitation-Only NASA Meeting - Unless You Are Lucky - November 8th, 2009 [November 8th, 2009]
- Close Call For Courtney Stadd - November 8th, 2009 [November 8th, 2009]
- Space: A Waste? - November 8th, 2009 [November 8th, 2009]
- Making NASA Cool - November 8th, 2009 [November 8th, 2009]
- Engaging JSC’s Next Gen: A Leadership Analysis - November 8th, 2009 [November 8th, 2009]
- Dumpster Diving for Rockets - November 8th, 2009 [November 8th, 2009]
- TEDx NASA - November 8th, 2009 [November 8th, 2009]
- Reflections On a Business Trip in Huntsville - November 8th, 2009 [November 8th, 2009]
- Staying the Course - November 8th, 2009 [November 8th, 2009]
- The Economics of Space - November 8th, 2009 [November 8th, 2009]
- Ideas at Work - November 8th, 2009 [November 8th, 2009]
- Blah Blah Blah - Why We Should Care About Social Media - November 8th, 2009 [November 8th, 2009]
- Will White House Speak Soon About NASA? - December 12th, 2009 [December 12th, 2009]
- Software Aids Design of Ares V Composite Shroud Structure - December 13th, 2009 [December 13th, 2009]
- ASDX Series of silicon pressure sensors - December 13th, 2009 [December 13th, 2009]
- Industry Update: Analysis & Simulation Software - December 13th, 2009 [December 13th, 2009]
- Battery Will Provide Backup Power for Space Shuttles - December 13th, 2009 [December 13th, 2009]
- NASA Employee Claims To Have Witnessed Hijacking Planning - December 13th, 2009 [December 13th, 2009]
- Big Party in The Mojave Tonight - December 13th, 2009 [December 13th, 2009]
- Looking at Boulders on the Moon - December 13th, 2009 [December 13th, 2009]
- SpaceBook Featured by White House - December 13th, 2009 [December 13th, 2009]
- New Ways to Use Constellation Stuff - December 13th, 2009 [December 13th, 2009]
- LaRC internal Poll Update - December 13th, 2009 [December 13th, 2009]
- Coalition for Space Exploration Does a (Much Needed) Reboot - December 13th, 2009 [December 13th, 2009]
- Lunar Orbiter: Comparing Old and New Images - December 13th, 2009 [December 13th, 2009]
- Boulder Trails On The Moon - December 13th, 2009 [December 13th, 2009]
- Vote for John Grunsfeld - National Geographic Adventurer of the YeAR - December 13th, 2009 [December 13th, 2009]
- Charlie Bolden at WIA/AIAA - December 13th, 2009 [December 13th, 2009]
- Live Webcast From The Lunar Orbiter Image Recovery Project - December 13th, 2009 [December 13th, 2009]
- Big Aerospace Warns of Job Cut Impact - December 13th, 2009 [December 13th, 2009]
- The Boulders of Copernicus - December 13th, 2009 [December 13th, 2009]
- shame on us - December 13th, 2009 [December 13th, 2009]
- 2009 Space Elevator Games - December 13th, 2009 [December 13th, 2009]
- Random Hacks of Kindness - December 13th, 2009 [December 13th, 2009]
- TEDx NASA Tickets Available to the Public - December 13th, 2009 [December 13th, 2009]
- It’s better in person - December 13th, 2009 [December 13th, 2009]
- Leading Amidst the Disruptive Innovation Storm - December 13th, 2009 [December 13th, 2009]
- Space: What’s NOT to Hope for? - December 13th, 2009 [December 13th, 2009]
- Government in the Digital Age - December 13th, 2009 [December 13th, 2009]
- SpaceUp – A Space Unconference - December 13th, 2009 [December 13th, 2009]
- Starfleet Academy? - December 13th, 2009 [December 13th, 2009]
- Crowdsourcing NASA - December 13th, 2009 [December 13th, 2009]
- Bringing Home The Bacon - December 14th, 2009 [December 14th, 2009]
- Anti-Space Mom with Pro-Space Kids - December 14th, 2009 [December 14th, 2009]
- How Quickly We Forget - December 14th, 2009 [December 14th, 2009]
- WISE Launch A Success - December 14th, 2009 [December 14th, 2009]
- Dynetics Buys Orion Propulsion - December 15th, 2009 [December 15th, 2009]
- New NASA Governance Structure Under Development - December 16th, 2009 [December 16th, 2009]
- Bolden Meets With Obama on Wednesday - December 16th, 2009 [December 16th, 2009]
- MSFC Procurement Doesn't Understand what "Open Source" Means - December 16th, 2009 [December 16th, 2009]
- Bolden Meets With Obama - December 17th, 2009 [December 17th, 2009]
- Parker Griffith AT MSFC Today - December 18th, 2009 [December 18th, 2009]
- Why Your NASA Computer May Not Work Properly - December 18th, 2009 [December 18th, 2009]
- Lakes and Fog on Titan - December 18th, 2009 [December 18th, 2009]
- Waterworld Found - December 18th, 2009 [December 18th, 2009]
- Pandora Could Exist - December 18th, 2009 [December 18th, 2009]
- Laurie Leshin Is The New ESMD Deputy AA - December 18th, 2009 [December 18th, 2009]