[meteorite-list] U.S. Demonstrates Production of Fuel for Missions to the Solar System and Beyond

[Ron Baalke]

http://www.jpl.nasa.gov/news/news.php?feature=4806

U.S. Demonstrates Production of Fuel for Missions to the Solar System and Beyond
Jet Propulsion Laboratory
December 22, 2015

The first U.S. production in nearly 30 years of a specialized fuel to 
power future deep space missions has been completed by researchers at 
the Department of Energy's Oak Ridge National Laboratory (ORNL) in Tennessee.

The production of 50 grams of plutonium-238 -roughly the mass of a golf 
ball - marks the first demonstration in the United States since the Savannah 
River Plant in South Carolina ceased production in the late 1980s.

Radioisotope power systems convert heat from the natural radioactive decay 
of the isotope plutonium-238 into electricity. These systems have been 
used to power the exploration of the solar system and beyond, from the 
Viking missions on Mars, to the Voyager spacecraft entering interplanetary 
space, and most recently powering the Curiosity Mars Rover and the New 
Horizons spacecraft sailing past Pluto.

"This significant achievement by our team mates at DOE signals a new renaissance 
in the exploration of our solar system," said John Grunsfeld, associate 
administrator for NASA's Science Mission Directorate in Washington. "Radioisotope 
power systems are a key tool to power the next generation of planetary 
orbiters, landers and rovers in our quest to unravel the mysteries of 
the universe."

The success of the engineers and technicians at ORNL comes two years after 
the project formally started with NASA funding, building on many years 
of research and testing. This demonstration of the key steps in fuel production 
will ensure that this vital space power technology will be available to 
provide electricity and heat for ambitious exploration missions of the 
solar system in this decade and beyond. In all, 27 past U.S. space missions 
have used this radioisotope power for their electricity and heat.

The Department of Energy (DOE) has successfully and safely provided radioisotope 
power systems for NASA, Navy and Air Force missions for more than 50 years.

"As we seek to expand our knowledge of the universe, the Department of 
Energy will help ensure that our spacecraft have the power supply necessary 
to go farther than ever before," said Franklin Orr, Under Secretary for 
Science and Energy at DOE. "We're proud to work with NASA in this endeavor, 
and we look forward to our continued partnership."

The currently available radioisotope power system, also supplied to NASA 
by the DOE, is called the Multi-Mission Radioisotope Thermoelectric Generator 
(MMRTG). Essentially a nuclear battery, an MMRTG can provide about 110 
watts of electrical power to a spacecraft and its science instruments 
at the beginning of a mission. On some missions, such as NASA's Curiosity 
Mars rover (now deep into its third Earth year seeking signs of habitable 
conditions on the Red Planet), the excess heat from the MMRTG can also 
be used to keep spacecraft systems warm in cold environments.

The next NASA mission planning to use an MMRTG is the Mars 2020 rover, 
due to be launched as part of NASA's Journey to Mars, to seek signs of 
past life on the Red Planet, test technology for human exploration, and 
gather samples of rocks and soil that could be returned to Earth in the 
future. Two (unfueled) MMRTGs are currently built and in storage at DOE 
facilities; one is reserved for Mars 2020, and the other could be used 
on a future mission. Fabrication of the fuel pellets for the Mars 2020 
MMRTG, using the existing U.S. supply of plutonium dioxide, is already 
underway.

Researchers will analyze the sample for chemical purity and plutonium-238 
content to determine whether adjustments need to be made before scaling 
up the process.

With continued coordination, both agencies plan to increase production 
after this important demonstration milestone and will start with about 
12 ounces (300 to 400 grams) of plutonium dioxide per year. After implementing 
greater automation and scaling up the process, ORNL will produce an average 
of 3.3 pounds (1.5 kilograms) in subsequent years.

Of the 77 pounds (35 kilograms) of existing plutonium-238, about half 
provide enough heat to meet power specifications of planned spacecraft. 
The remainder, due to its age, does not meet specifications, but can be 
blended with newly produced Pu-238 to extend the usable inventory.

The DOE's Office of Nuclear Energy develops, manufactures, tests and delivers 
radioisotope power systems for space exploration and national security 
missions and maintains responsibility for nuclear safety throughout all 
aspects of the missions.

NASA's Radioisotope Power System (RPS) program, managed by NASA Glenn 
Research Center in Cleveland, is funding the development of new, higher 
efficiency thermoelectric materials that could be incorporated into a 
next-generation enhanced MMRTG that would provide about 25 percent more 
power at the start of a typical mission, and 50 percent more power at 
the end of a mission.

NASA's Jet Propulsion Laboratory, Pasadena, California, is part of the 
RPS program and manages several missions that utilize radioisotope power, 
including the Curiosity Mars rover and the Cassini spacecraft at Saturn.

NASA works with the international science community to explore our solar 
system and beyond. We look to answer big questions that intrigue us all 
like how did our solar system originate and change over time, how did 
the universe begin and evolve, what will be its destiny, and are we alone?


Media Contact

Dwayne Brown 
NASA Headquarters, Washington
202-358-1726
dwayne.c.brown at nasa.gov

Bart Jackson
Department of Energy Headquarters, Washington
202-586-1099
Bartlett.Jackson at hq.doe.gov

2015-386