Feb 16, 2021 - Science

Breaking down the role nuclear power could play in getting people to Mars

Artist's illustration of a nuclear propulsion system and habitat around Mars. Image: NASA
Artist's illustration of a nuclear propulsion system and habitat around Mars. Image: NASA

Nuclear power is a good bet to get people to and from Mars, according to a new report. However, there's still a long way to go before it's viable.

Why it matters: NASA has plans to send astronauts to Mars in the 2030s, but the technology needed for such an extreme mission is still in development.

What's happening: The new report from the National Academy of Sciences suggests NASA should start investing resources into learning more about how to safely test and use nuclear propulsion to get cargo and people to Mars.

  • NASA has used chemical propulsion — think fiery rockets — for its human exploration of the Moon, but solely relying on rockets for a trip to and from Mars could be costly and infeasible.
  • The report, instead, assessed the current state of nuclear electric propulsion (NEP) and nuclear thermal propulsion (NTP) with an eye toward launching a crewed mission to Mars in 2039.

What they're saying: "Nuclear propulsion systems have the potential to substantially reduce trip time compared to non-nuclear approaches," Roger Myers co-chair of the committee that wrote the report, said in a statement.

  • "Synergy with other space mission applications and terrestrial power programs is also significant and will bring about added value.”

Yes, but: While both NEP and NTP could theoretically get people to Mars more quickly than chemical propulsion alone, both technologies have current limitations.

  • NEP, for example, would need its power scaled up by many orders of magnitude, according to the report, something that hasn't been achieved before.
  • With NEP, NASA would also need to develop some kind of chemical propulsion to get the craft out of Earth's and Mars' orbits.
  • NTP, on the other hand, wouldn't need a complementary chemical system, but its propellant would need to stay warm, which is not the easiest thing to accomplish in space.
  • The report's authors also note it's difficult to test NTP safely on the ground.

What's next: The report recommends NASA should make "a significant set of architecture and investment decisions in the coming year," if the space agency hopes to take nuclear options seriously.

  • "Significant acceleration in the pace of technology maturation is required if NASA and its partners are to complete this mission within the stated timeline," Bobby Braun, a co-chair of the committee that wrote the report, said in the statement.
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