WASHINGTON – The race to land humans on Mars, NASA is blowing the cobwebsoff a technology it shelved in the 1970s — nuclear-powered rockets. Lastyear, NASA partnered with BWXT Nuclear Energy Inc for an $18.8 millioncontract to design a reactor and develop fuel for use in a nuclear-thermalpropulsion engine for deep-space travel. While that small start is a longway from the the heady days of the Space Race of the Cold War, it marks theUS return to an idea that is also being pursued by Russia and China.
Unlike conventional rockets that burn fuel to create thrust, the atomicsystem uses the reactor to heat a propellant like liquid hydrogen, whichthen expands through a nozzle to power the craft. That doubles theefficiency at which the rocket uses fuel, allowing for a ‘drasticallysmaller’ craft and shorter transit time, said Stephen Heister, a professorat Purdue University’s School of Aeronautics and Astronautics. “This factoris absolutely huge, especially for very difficult missions that necessitatea lot of propellant such as a Mars flight.”
While the system would be a niche market in the global nuclear industry, itcould be highly lucrative for the company that cracks the technology,especially for nations like the US, where the atomic energy sector has beenin the doldrums for decades. “The application of BWXT capabilities formanufacturing systems for space applications is a modest but extremelyimportant area of technical development,” said Jonathan Cirtain, vicepresident for advanced technology programs at BWXT. “The size of the marketis directly tied to how easily these systems can be manufactured and howthese in-space nuclear power systems for either electrical or propulsivepower compare to alternative sources.”
In the US, Europe and Japan, tighter regulations, construction delays,public mistrust and political opposition stalled nuclear power developmentand helped push industry pioneers like Westinghouse Electric Co intobankruptcy. And countries like Germany, South Korea and Taiwan are lookingto renewable energy or cheap natural gas instead, leaving China and Russiato take the lead in the development of new nuclear plants. Russia’s RosatomCorp has said it plans this year to test a prototype nuclear engine for aspacecraft that can go to Mars. Russia so far has led research in the fieldand has deployed more than 30 fission reactors in space, according to theWorld Nuclear Association. China aims to use atomic-powered shuttles aspart of its space exploration plans through 2045, according to state XinhuaNews Agency.[image: NASA Mars manned mission, nuclear-powered rocket, Space Race, Marsflight, hydrogen fuel, global nuclear industry, Elon Musk Mars, renewableenergy sources, atomic-powered shuttles, SpaceX, radioactive material,thermoelectric generators]Last year, NASA partnered with BWXT NuclearEnergy Inc for an $18.8 million contract to design a reactor and developfuel for use in a nuclear-thermal propulsion engine for deep-space travel.(File Photo)
NASA faces competition in the race to Mars from industrialists like ElonMusk, who have also vowed to get people to the red planet. SpaceExploration Technologies Corp, founded by Musk, is developing a liquidoxygen and methane fueled engine. Jeff Bezos’ Blue Origin is testing anengine that uses liquid oxygen and liquefied natural gas. NASA also has itseye on atomic technology to power human colonies once they get to Mars. Theagency and the Department of Energy are developing a space-ready nuclearfission reactor, known as Kilopower, that could provide up to 10 kilowattsof power and be deployed on other planets and moons. NASA has employedradioisotope thermoelectric generators — batteries that run off the heatfrom radioactive materials — on previous space missions, including the MarsCuriosity rover.
For BWXT, the NASA contract is the latest in its long pedigree in theindustry. The company is an offshoot of Babcock & Wilcox, which designedand built some of the world’s first nuclear reactors and atomic-poweredsubmarines, and has worked on feasibility studies for nuclear propulsionsystems in space with different US agencies over the past few decades. Itslatest contract runs through September 2019. In NASA’s human explorationplan for Mars, developed in 2009, nuclear thermal propulsion is thepreferred option. Two other technologies being considered aresolar-electric and chemical propulsion. Nuclear thermal rockets were firstresearched and tested by NASA between 1955 and 1972, before the program wascanceled by Congress over cost concerns. NASA has revisited nuclear thermalpropulsion a few times over the years, but it didn’t go beyond feasibilitystudies.
“Significant advances in material research and technology development haveallowed for new materials to be considered for the critical components ofthe reactor,” said BWXT’s Cirtain. A nuclear propulsion system can providethe flexibility to abort and return even a few months into a mission, saidJeffrey Sheehy, chief engineer of the Space Technology Mission Directorateat NASA. “The novelty of the reactor design limits the amount of nuclearfuel required to execute a propulsion maneuver. It would be possible torestart that engine multiple times,” he said.
While the crew would have to be shielded from the reactor’s radiation, thehigher speed of a nuclear-powered craft would cut the time astronauts areexposed to cosmic radiation, according to Purdue’s Heister. Nuclearpropulsion may be the favored option for deep space travel, but theintricacies of the technology and the testing mean that development costscould be a major barrier, said Claudio Bruno, a professor at the Universityof Connecticut. Using technology developed by NASA decades ago could helpspeed up the process, he said.
Getting to Mars is no small task — it requires a 55 million-kilometer (34million-mile) space flight, more than 100 times the distance from Earth tothe Moon. NASA probably won’t send humans to orbit the planet until atleast the early 2030s. Ground testing would require a costly system thatcaptures and scrubs exhaust to remove tiny radioactive materials, accordingto Purdue University’s Heister. “Space exploration is a captivating passionthat many folks have – they are not necessarily motivated by profit,” saidHeister. “In our business, we joke that the best way to become amillionaire in the space propulsion industry is to start out as abillionaire.”