NASA has revealed plans to create a nuclear-powered rocket that could send astronauts to Mars in just 45 days.
The agency, which has partnered with the Pentagon’s Defense Advanced Research Projects Agency (DARPA) to design the rocket, announced on Tuesday (Jan. 24) that it could build a working nuclear thermal rocket engine as soon as 2027.
NASA’s current rocket systems (including the Space Launch System which last year sent the Artemis 1 rocket on a historic round-trip to the moon) are based on the century-old, traditional method of chemical propulsion — in which an oxidizer (which gives the reaction more oxygen to combust with) is mixed with flammable rocket fuel to create a flaming jet of thrust. The proposed nuclear system, on the other hand, will harness the chain reaction from tearing apart atoms to power a nuclear fission reactor that would be “three or more times more efficient” and could reduce Mars flight times to a fraction of the current seven months, according to the agency.
"DARPA and NASA have a long history of fruitful collaboration in advancing technologies for our respective goals, from the Saturn V rocket that took humans to the Moon for the first time to robotic servicing and refueling of satellites," Stefanie Tompkins, the director of DARPA, said in a statement. "The space domain is critical to modern commerce, scientific discovery, and national security. The ability to accomplish leap-ahead advances in space technology… will be essential for more efficiently and quickly transporting material to the moon and, eventually, people to Mars."
NASA began its research into nuclear thermal engines in 1959, eventually leading to the design and construction of the Nuclear Engine for Rocket Vehicle Application (NERVA), a solid-core nuclear reactor that was successfully tested on Earth. Plans to fire the engine in space, however, were mothballed following the 1973 end of the Apollo Era and a sharp reduction of the program's funding.
Nuclear engines can fire more efficiently than their chemical counterparts, and for extended periods of time — propelling rockets faster and further. They are split into two types: Nuclear Electric Propulsion (NEP) reactors, which work by generating electricity that strips electrons from noble gases such as xenon and krypton before blasting them out of the spacecraft’s thruster as an ion beam; and Nuclear Thermal Propulsion (NTP) reactors, which is the type being investigated by NASA, uses the fission reaction to heat a gas (typically hydrogen or ammonia) so that it expands through a nozzle to provide thrust.
The Artemis 1 flight was the first of three missions testing the hardware, software and ground systems intended to one day establish a base on the moon and transport the first humans to Mars. This first test flight will be followed by Artemis 2 and Artemis 3 in 2024 and 2025/2026, respectively. Artemis 2 will make the same journey as Artemis 1 but with a four-person human crew, and Artemis 3 will send the first woman and the first person of color to land on the moon's surface, at the lunar south pole.
"It's historic because we are now going back into space, into deep space, with a new generation." NASA Administrator Bill Nelson said following Artemis 1’s launch. "One that marks new technology, a whole new breed of astronauts, and a vision of the future. This is the program of going back to the moon to learn, to live, to invent, to create in order to explore beyond."
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Ben Turner is a U.K. based staff writer at Live Science. He covers physics and astronomy, among other topics like tech and climate change. He graduated from University College London with a degree in particle physics before training as a journalist. When he's not writing, Ben enjoys reading literature, playing the guitar and embarrassing himself with chess.
Why does the article not mention speed and the physics of achieving it as well as the deceleration? Both transitions will greatly affect any passengers. I'm sure it's ability to accelerate will outstrip the astronaut's ability to withstand the G-force for the time required to attain maximum velocity, so the same will be true for slowing that thing down!Reply
I imagine the advantage comes not from tremendous G-forces, but rather from the nuclear rocket's ability to propel the craft for a much longer time than a chemical rocket.HollandArc said:Why does the article not mention speed and the physics of achieving it as well as the deceleration? Both transitions will greatly affect any passengers. I'm sure it's ability to accelerate will outstrip the astronaut's ability to withstand the G-force for the time required to attain maximum velocity, so the same will be true for slowing that thing down!
As I understand it, a chemical Mars rocket is essentially launched on a ballistic trajectory, depending on achieving the exact speed and direction at the moment the main engine shuts off, to carry the craft on the path to its rendezvous, at the point in Mars' orbit where Mars will be when the craft arrives. This is why it takes so long, because the vehicle is essentially coasting, for almost all of its journey. The reason the rocket doesn't continue to burn, to get there faster, is that that would require carrying so much fuel that the rocket couldn't even get off the ground.
The advantage of the nuclear rocket, as I understand it, would be that the nuclear rocket would be able to provide continuous, reasonable thrust, for a long period of time, with a much, much smaller weight of fuel. So it could continue to fire along the way, making for a greater top speed, while still allowing for turnaround and reverse thrust to slow down for landing.
I don't know what sort of max thrust the nuclear rocket could produce; they might use a chemical rocket booster to get it into space, before turning on the nuke.