NASA has achieved a breakthrough in space propulsion technology, albeit at a small experimental level. Researchers at the space agency have successfully tested the microwave thrusters that can work without any propellant. It was considered impossible because the propulsion system violates the law of conservation of momentum.
NASA's technology could potentially make spacecraft inexpensive
Scientists at NASA's Johnson Space Center presented a paper last week, saying that they indeed achieved a small amount of thrust from a microwave thruster system that had no traditional fuels. If the space agency succeeds in replicating and scaling up the results, it could make ultra-fast spacecraft at far less cost. Such a spacecraft could take humans to Mars in just a few weeks.
NASA said the electric propulsion device generated a force that is not attributable to any classical electromagnetic phenomena. The amount of thrust generated was only 30-50 MicroNewtons (mN), even less than the weight of an iPhone. But the fact that the system generated even a small amount of thrust without any onboard source of fuel clearly violates the law of conservation of momentum
The thruster works by harnessing the power of subatomic quantum particles that consistently pop in and out of existence. Researchers performed the test on a low-thrust torsion pendulum that could detect force at a single-digit MicroNewton (mN) level in a steel vacuum chamber. If replicated at a large-scale, the discovery could bring down the cost of maintaining satellites and interstellar travel.
NASA running behind British and Chinese researchers
The origins of this kind of propulsion system go back to a British scientist named Roger Shawyer, who developed EmDrive. Shawyer claimed that his EmDrive could generate thrust "by rocketing microwaves around in a chamber." It doesn't need any propellant because microwaves could easily be produced using solar power. Chinese scientists also developed their own version of the system in 2012.
The system that NASA tested was constructed by an American researcher named Guido Fetta. Fetta named his system "Cannae Drive." The system produced less than 0.1% of thrust produced by Chinese researchers. Anyway, it suggests that the technology works. Chinese researchers said their system generated enough thrust to potentially fuel a satellite.