University of Washington researchers and scientists at a Redmond-based space-propulsion company (John Slough and MSNW) are building components of a fusion-powered rocket aimed to clear many of the hurdles that block deep space travel, including long times in transit, exorbitant costs and health risks.
John Slough and his team have published papers calculating the potential for 30- and 90-day expeditions to Mars using a rocket powered by fusion, which would make the trip more practical and less costly.
Is this really feasible? Slough and his colleagues at MSNW have demonstrated successful lab tests of all portions of the process. Now, the key will be combining each isolated test into a final experiment that produces fusion using this technology. The research team has developed a type of plasma that is encased in its own magnetic field. Nuclear fusion occurs when this plasma is compressed to high pressure with a magnetic field. The team has successfully tested this technique in the lab.
The team is working to bring it all together by using the technology to compress the plasma and create nuclear fusion. Slough hopes to have everything ready for a first full test at the end of the summer.
To power a rocket, the team has devised a system in which a powerful magnetic field causes large metal rings to implode around this plasma, compressing it to a fusion state. The converging rings merge to form a shell that ignites the fusion, but only for a few microseconds. Even though the compression time is very short, enough energy is released from the fusion reactions to quickly heat and ionize the shell. This super-heated, ionized metal is ejected out of the rocket nozzle at a high velocity. This process is repeated every minute or so, propelling the spacecraft.
Mars in 30 days
Mission Design Architecture for the Fusion Driven Rocket – The Fusion Driven Rocket (FDR) described in this work offers a realistic approach to fusion propulsion systems. FDR allows for direct energy transfer to the propellant requiring no conversion to electricity. Addtionally, the propellant requires no significant tankage mass by being a solid, yet can still be rapidly heated and accelerated to high exhaust velocity (over 20 km/s). But perhaps most importantly, unlike many other fusion and fission concepts, there is no significant physical interaction with the spacecraft thereby limiting thermal heat load, spacecraft damage, and radiator mass. This paper will discuss the basic physics of the FDR and the fusion method employed as well as focus on in – depth analysis of the mission architectures enabled by the FDR.
While a 90-day transit to Mars offers a good balance of payload mass fraction and transit time at even modest estimations of fusion gain , the possibility of very high energy yields make extremely rapid transits to Mars quite feasible. To investigate this, a 30 -day transit to Mars was considered. The ΔV budget for such a mission is very high, ranging from 98 km/s at a full 30 day burn to 45 km/s for a 0.1 Day- burn (which approximates the Lambert problem). For such high ΔV’s a fusion again of 40 would not result in optimal mission parameters. More ambitious gains of 200 , however, show that his mission is quite favorable. The optimal burn time for such a mission is 6 days
The fusion driven rocket test chamber at the UW Plasma Dynamics Lab in Redmond. The green vacuum chamber is surrounded by two large, high-strength aluminum magnets. These magnets are powered by energy-storage capacitors through the many cables connected to them.
3 Lithium Liners, Translating and Compressing an FRC target 3D view
NASA NIAC Phase 2 Spring Symposium poster