University of Washington researchers are working on a new design for a fusion-driven rocket that they say could cut a round-trip voyage to Mars to 90 days or less.
“The future of manned space exploration and development of space depends critically on the creation of a dramatically more proficient propulsion system for in-space transportation,” wrote the project team in a paper on their propulsion design. “Nuclear fuel contains energy densities that dwarf the energy of any chemical combustion. The fusion-driven rocket … offers a realistic approach to fusion propulsion systems.”
If their design works as they believe it will, their engine could propel a Mars-bound spacecraft at more than 12 miles per second. If they were able to build a working craft by 2020, the red planet would be around 36 days travelling time from Earth at that speed. According to astronomy professor Courtney Seligman, in October of that year the two planets will be a relatively close 38.6 million miles apart.
The scientists, who have spun-off their research into a private company called MSNW, say they have demonstrated successful lab tests of all portions of the process and now need to combine them into one experiment to produce a fusion reaction. Their method uses magnetic fields to implode three lithium rings around a plasma, causing a fusion reaction that expands hot, ionized propellant out of a magnetic nozzle at the rear of the craft. The process is repeated about once a minute to maintain propulsion.
They hope to run the complete experiment during the summer to understand whether their design works.
In the video above, the plasma (purple) is injected while lithium metal rings (green) rapidly collapse around the plasma, creating fusion.
The video above, taken from a 3-D computer simulation, shows three lithium rings as they collapse around plasma material. The scientists ran the experiment in real-life at the UW Plasma Dynamics Laboratory, delivering 1 million amps of electricity to a magnet in a fraction of a second, which caused a field that compressed a target of aluminum rings.
“I think everybody was pleased to see confirmation of the principal mechanism that we’re using to compress the plasma,” said lead researcher John Slough, a UW aeronautics and astronautics professor and president of MSNW.
High speed with much less fuel
Their project is being funded by NASA’s Innovative Advanced Concepts Program, which is looking to decrease the estimates of a four-year round-trip expedition to Mars using current technology.
Besides the mind-blowing speeds their design could theoretically achieve, it would do it while needing to carry much less fuel than current technologies would require. The researchers say a sand grain’s worth of fusion fuel is equivalent to a gallon of rocket fuel. ““We are hoping to give us a much more powerful source of energy in space that could eventually lead to making interplanetary travel commonplace,” Slough said in a university statement.
By the team’s estimates of at least 20 km per second velocity of propellant coming out of their fusion rocket, the craft would fly at a minimum speed of 44,640 miles per hour.
Another team, at the University of Alabama-Huntsville, reported on by Txchnologist last September, is investigating a similar process to achieve fusion. They estimate that their engine might be able to propel a craft at 62,600 mph.
Top Image: A concept image of a spacecraft powered by a fusion-driven rocket. In this image, the crew would be in the forward-most chamber. Solar panels on the sides would collect energy to initiate the process that creates fusion. Courtesy University of Washington/NSMW.