Nuclear thermal propulsion project to develop new technology for NASA missions to Mars and beyond
Part of NASA’s Game Changing Development (GCD) Programme, the $18.8m contract will see Virginia-based BWX Technology initiate the design of a reactor to power a nuclear thermal promotion (NTP) system for a future crewed mission to Mars. The project, which is expected to run through 2019 subject to Congressional approval, aims to develop a reactor fuelled by low enriched uranium; that is, with a uranium-235 concentration below 20 per cent.
NTP technology is seen as having great potential for long distance space exploration. It uses a nuclear reactor to heat an inert fuel — most likely to be liquid hydrogen — to high temperatures and expel it from a rocket nozzle.
Theoretically, an NTP engine can deliver twice the specific impulse of the best chemical rocket engine, with half of the liftoff mass: payload mass could therefore be doubled or tripled.
“That capability makes nuclear thermal propulsion ideal for delivering large, automated payloads to distant worlds,” NASA said.
Using an NTP engine for a Mars mission could cut the transit time from Earth from six months to four. This would reduce the crew’s exposure to both microgravity and to cosmic radiation, both of which have serious potential effects on health.
“As we push out into the solar system, nuclear propulsion may offer the only truly viable technology option to extend human reach to the surface of Mars and to worlds beyond,” said Sonny Mitchell, Nuclear Thermal Propulsion project manager at the Marshall Space Centre in Huntsville, Alabama from where the project will be directed . “We’re excited to be working on technologies that could open up deep space for human exploration.”
NTP is not new to NASA; the agency had a long-running programme investigating and developing the technology from 1958 to 1972.
The NERVA (Nuclear Engine For Rocket Vehicle Application) project got as far as building and testing prototype engines with flight-certified components to the point where it was deemed ready for integration into a spacecraft, but Congress cancelled a planned Mars mission before this could happen and the engine was never flight-tested.
In the new project, BWXT is to develop and test a new type of low enriched uranium fuel element known as “Cermet” – ceramic metallic. Such materials are used in specialised industrial cutting equipment, but for NTP applications would require isotopically-pure tungsten, which is currently not possible to do affordably.
“BWXT is extremely pleased to be working with NASA on this exciting nuclear space program in support of the Mars mission,” said Rex D. Geveden, BWXT’s president and CEO. “We are uniquely qualified to design, develop and manufacture the reactor and fuel for a nuclear-powered spacecraft. This is an opportune time to pivot our capabilities into the space market where we see long-term growth opportunities in nuclear propulsion and nuclear surface power.”
The early stage of the project will first involve a feasibility study for the use of the fuel. It will then spend a year testing and refining its ability to produce full-size Cermet fuel elements which will be tested in a purpose-built facility at Marshall.
BWXT’s roots extend back to the earliest days of electrical power. Formerly part of Babcock Wilcox, its forerunners provided boilers for the first power stations in the US, and it was awarded the first contract to develop nuclear propulsion systems for submarines and surface ships in the 1940s. Its involvement in NTP dates back to 1987.
Anything based on expelling a propellant is inherently limited. It is a stepping stone technology only but totally insufficient for navigation around the solar system and beyond.
The emdrive which removes the need for a propellant is surely a superior system for deeper space travel.
Apparently Ben Rich, who was the second director of Lockheed Skunk Works from 1975-1991 claimed we already have the technology for inter-stellar travel, that there is in fact an “error in the equations” but they are so deeply entwined with military projects they will never see the light of day.
Interesting thought.
This is the most interesting project I’ve heard for some while. Anything to keep the momentum for space exploration must be good.
With rocketry still somewhat of an art and regular explosions still occurring during launch phases across a range of rockets by various manufacturers, nations and organisations I wonder of the environmental risk of a rocket with these type of engine malfunctioning and exploding and even though low level U235 is used what the subsequent effects would be.
Hi Geof,
Glad to hear that you’re curious about NTP. Fortunately, the way that the reactor has been designed already considers the possibility of a launch failure, and as such the reactor will not be “turned on” until it’s already in space, meaning that there’ll be no environmental effects!
This is a non-starter, until “intrinsically safe” transport to low Earth orbit, is possible, which it is not at this time safe to send a nuclear reactor up in this manner.
What could be done, however, is to send up the vessel/reactor empty, and load it in space, while separately bringing up fuel assemblies packaged in “detonation survivable” cannisters, and loading the reactor robotically while still in orbit. The mission is too large to make a single launch anyway, so in orbit assembly required, batteries not included, sorry.
Hi James,
Are you aware that humans have already launched over 30 reactors in space? I think you’ll be pleased to hear that it’s completely achievable to launch a fueled reactor.
Old technology, yes, but a small but useful step on from the current chemical propulsion system. Ben Rich died 22 years ago and his quote is a UFOlogist’s myth. https://noriohayakawa.wordpress.com/2016/07/01/ben-rich-erroneously-misquoted-by-the-ufo-community/
Like cold fusion, the EMdrive is an impossibility. A lot of time and money has been wasted in futile attempts to repeat the original (clearly flawed) experiment.
Didn’t NASA announce the validity of the EM drive in vacuum a couple of years ago (covered by this same journal)?
What makes you so sure cold fusion is impossible? Andrea Rossi is claiming he can demonstrate it working late this year. Whilst you may be right, I prefer to wait and see.
A NASA paper on the EM drive passed peer review last November, but wee didn’t report on it.
NASA never announced validity of EM drive, just that they have positively tested it – there is a slight difference in both, the latter means that so far it has not been disproved, however the positive result could be due to some undetected test flaw. The real test would be in space, when it truly would have to prove its propulsion, or scaling it up to achieve higher thrusts. At the moment the current thrust is very minuscule.
With regard to fusion (cold fusion), it is obviously a fact, just the known ways to achieve it generate less energy then they consume – but it does not mean it impossible, just not practical.