Fusion-powered rocket could send humans to Mars

  • 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. Credit: University of Washington, MSNW
  • 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 aluminium magnets. These magnets are powered by energy-storage capacitors through the many cables connected to them. University of Washington, MSNW
Date:15 April 2013 Tags:, , , , ,

Human travel to Mars might just be in the cards, thanks to scientists who are working to make a fusion-powered rocket a reality.

Researchers at the University of Washington and at 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.

“Using existing rocket fuels, it’s nearly impossible for humans to explore much beyond Earth,” said lead researcher John Slough, a UW research associate professor of aeronautics and astronautics. “We are hoping to give us a much more powerful source of energy in space that could eventually lead to making interplanetary travel commonplace.”

Nasa estimates a round-trip human expedition to Mars would take more than four years using current technology. The sheer amount of chemical rocket fuel needed in space would be extremely expensive – the launch costs alone would be more than $12 billion (over R100 billion).

Slough and his team have published papers calculating the potential for 30- and 90-day expeditions to Mars using a rocket powered by nuclear fusion, which would make the trip more practical and less costly.

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, Slough said.

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.

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 ionise the shell. This super-heated, ionised metal is ejected out of the rocket nozzle at a high velocity. This process is repeated every minute or so, propelling the spacecraft.

Slough hopes to have everything ready for a first test toward the end of the year.

Nuclear fusion may draw concern because of its application in nuclear bombs, but its use in this scenario is very different, Slough said. The fusion energy for powering a rocket would be reduced by a factor of 1 billion from a hydrogen bomb, too little to create a significant explosion. Also, Slough’s concept uses a strong magnetic field to contain the fusion fuel and guide it safely away from the spacecraft and any passengers within.

This video, taken from a 3D computer simulation, demonstrates the metal-crushing process i.e. shows three lithium rings as they collapse around plasma material.

Michelle Ma | University of Washington