NASA and the China National Space Agency (CNSA) plan to mount the first crewed missions to Mars in the next decade. These will commence with a crew launching in 2033, with follow-up missions launching every 26 months to coincide with Mars and Earth being at the closest point in their orbits. These missions will culminate with the creation of outposts that future astronauts will use, possibly leading to permanent habitats. In recent decades, NASA has conducted design studies and competitions (like the 3D-Printed Habitat Challenge) to investigate possible designs and construction methods.
For instance, in the Mars Design Reference Architecture 5.0, NASA describes a “commuter” architecture based on a “centrally located, monolithic habitat” of lightweight inflatable habitats. However, a new proposal envisions the creation of a base using organisms that extract metals from sand and rock (a process known as biomineralization). Rather than hauling construction materials or prefabricated modules aboard a spaceship, astronauts bound for Mars could bring synthetic bacteria cultures that would allow them to grow their habitats from the Red Planet itself.
We live in an era of renewed space exploration, where multiple agencies are planning to send astronauts to the Moon in the coming years. This will be followed in the next decade with crewed missions to Mars by NASA and China, who may be joined by other nations before long. These and other missions that will take astronauts beyond Low Earth Orbit (LEO) and the Earth-Moon system require new technologies, ranging from life support and radiation shielding to power and propulsion. And when it comes to the latter, Nuclear Thermal and Nuclear Electric Propulsion (NTP/NEP) is a top contender!
NASA and the Soviet space program spent decades researching nuclear propulsion during the Space Race. A few years ago, NASA reignited its nuclear program for the purpose of developing bimodal nuclear propulsion – a two-part system consisting of an NTP and NEP element – that could enable transits to Mars in 100 days. As part of the NASA Innovative Advanced Concepts (NIAC) program for 2023, NASA selected a nuclear concept for Phase I development. This new class of bimodal nuclear propulsion system uses a “wave rotor topping cycle” and could reduce transit times to Mars to just 45 days.