Column | Now is the time for Congress to order the nuclear option

U.S. urgently needs to develop nuclear propulsion systems in space

As NASA finally launches its first Space Launch System (SLS) mission, the United States has failed to invest in the critical space propulsion technology needed to send astronauts to Mars.

The United States must develop space-based nuclear propulsion technology to enable human missions to Mars in the 21st century. Congress should immediately direct NASA and the Department of Energy to work with university-affiliated research centers or federally funded research and development centers to create a new National Space Nuclear Propulsion Laboratory.

It is naive and contrary to the national interest for the United States to rely on expensive, outdated, slow, single-use chemical propulsion rockets such as the SLS to transport astronauts to Mars. Instead, the United States must aggressively invest in the development of nuclear propulsion systems in space.

Nuclear technologies, including nuclear electric propulsion (or “NEP”) and nuclear thermal propulsion (or “NTP”), will be game-changers for space travel, with profound implications for the speed, agility and capabilities of deep space missions.

The increased propulsion of the nuclear system would allow humans to travel to Mars at a more regular cadence than the current “every 26-month” mission launch window. Nuclear propulsion will also power astronauts on Mars missions to abort and return to Earth in an emergency.

A recent study by the National Academy of Sciences concluded that the U.S. should pursue further research into NEP and NTP systems for human missions to Mars, but did not prioritize either. Experts have concluded that if the U.S. begins serious development of the NTP system today, we could have an operational system by 2039, the base date for the first U.S. manned mission to Mars. The NTP system will provide fast, efficient propulsion for our human missions to Mars.

This image shows a transit habitat mission to Mars using a nuclear electric propulsion (NEP) propulsion system. Nuclear propulsion will offer significant advantages over conventional chemical propulsion systems, providing greater power while providing greater flexibility in the architecture of human missions to Mars.Credit: NASA

A NASA colleague once brilliantly explained that NEP and NTP are “the difference between a Prius and a Porsche.” Both vehicles will take you to your destination, but each has different speeds and tradeoffs.

Getting these two systems running will provide decades of capability and open the door to human deep space exploration. The development of this new technology is no easy task – both NEP and NTP systems now require significant technical research and development to create a working system that is ahead of other spacefaring nations.

As the United States did with the Apollo program, we will have to start from scratch, inventing new materials, engines and nuclear systems that do not exist today. That’s why we need to act now.

To enable these new nuclear propulsion systems, we should rely on the real brainpower of our nation—our academic institutions and American industry.

While federal agencies such as DARPA (their DRACO mission) and NASA (their Fission Surface Dynamics program) have conducted some excellent small-scale R&D projects, government agencies lack the cutting-edge facilities and intellectual capacity to make this important technological development a reality Outcomes by the mid-2030s.

The new national laboratory, led by a university-affiliated partner, will provide significant cost savings for the government. Combining the smarts of academia with the lean business sense of industry will be more cost-effective than designating this work to be done in small increments by government agencies that are not prepared to take on the challenges of this technology.

Federal agencies should provide funding and real estate, as well as safety oversight and services, for new labs led by university-affiliated organizations. Academia and industry can always find ways to do actual R&D faster, better, and cheaper than government bureaucrats.

American industry is ready to join this important aerospace technology race. America’s best and brightest from multiple fields of business can push down the long poles of nuclear propulsion in space, while advancing the actual commercial use of this new technological capability, right here on Earth. As with any new disruptive technology, economic opportunities and societal benefits will follow once these systems are proven through space demonstration missions.

It’s time to stop waiting for sluggish space policy scribbles from the Space Council or other government agencies to expand research and analysis. Congress should direct the creation of a new hybrid national laboratory dedicated to creating and demonstrating advanced space nuclear propulsion systems within a decade. Without immediate direction from Congress, the United States will continue to lag behind the critical technologies needed to explore deep space for our future humanity.


David Steitz Most recently served as NASA’s deputy administrator for technology, policy and strategy and the agency’s deputy chief technology officer. Steitz retired from NASA in May, ending a 32-year career at NASA Headquarters in Washington.

This article originally appeared in the September 2022 issue of SpaceNews Magazine.

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