Humans have been captivated by Mars for centuries. People dream of one day having a colony on our neighboring planet, but that future is fraught with many challenges. Although we have sent rockets carrying rovers to the surface, carrying humans will place additional demands: a larger spacecraft with different propulsion systems, more power during the stay, and resources to make a return journey.
Additionally, human health is of the utmost concern. Exposure to cosmic radiation and microgravity during a long flight to Mars poses many biological challenges, including decreased muscle mass and bone density, visual impairment, and an increased risk for degenerative diseases and cancers. Not to mention the potential for psychological stress because being in isolation with only the other crew members affects mental health.
Space nuclear technology isn’t new. As early as the 1950s, propulsion systems based on the fission of uranium atoms were being designed for rockets. Nuclear fission propulsion systems harness the heat released when uranium atoms split. The energy then is used either to produce electricity or to directly heat a propellant such as hydrogen. To date, only one US-built nuclear reactor for space has successfully reached orbit; the country’s other rockets remain reliant on chemical reactions for propulsion.
The technological limits of what chemical propulsion can provide have been reached. Human exploration cannot go much beyond the Moon without a new type of engine. Although chemical propulsion will still be used to escape Earth’s gravity well, nuclear propulsion can expel propellant faster and allow a rocket to travel farther using less fuel. On the surface of another planet, nuclear systems may be the best way to power any permanent space bases, especially when greater power is needed and when solar power won’t suffice. New nuclear efforts are currently being funded to facilitate missions to the Moon, Mars, and beyond.
To read more, click here.