The U.S. needs to invest more in nuclear-powered spacecraft to be competitive with nations like China, experts say.
During a government hearing on Wednesday (Oct. 20), experts from NASA and the aerospace industry discussed how the U.S. stacks up against other nations when it comes to developing new nuclear propulsion technology. And, according to them, the U.S. needs to move quickly if it wants to keep up. The congressional committee hearing, called "Accelerating deep space travel with space nuclear propulsion," took place before the U.S. House of Representatives' Science, Space and Technology Committee.
"Strategic competitors including China are aggressively investing in a wide range of space technologies, including nuclear power and propulsion," Bhavya Lal, NASA's senior advisor for budget and finance, said in the hearing. "The United States needs to move at a fast pace to stay competitive and to remain a leader in the global space community."
NASA has previously discussed how nuclear propulsion technology could allow the agency to send humans to Mars more quickly than by using traditional chemical rockets.
"Nuclear electric propulsion systems use propellants much more efficiently than chemical rockets but provide a low amount of thrust," NASA has said. "Nuclear electric propulsion systems accelerate spacecraft for extended periods and can propel a Mars mission for a fraction of the propellant of high-thrust systems."
There are multiple types of nuclear propulsion that could be used in space technology. With nuclear electric propulsion, thermal energy from a nuclear reactor is turned into electric energy that powers whatever type of electrical thruster or propulsion tech that a spacecraft uses. With nuclear thermal propulsion, reactors heat up propellants like hydrogen and then the gas from that reaction is ejected, creating thrust. This can create a lot more thrust than electric propulsion systems.
According to the experts at Wednesday's hearing, if NASA wants to get to Mars soon, time is of the essence. "If the United States is serious about leading in a human mission to Mars, we have no time to lose," U.S. Rep. Don Beyer (D-Va.), who chairs the committee, said. Beyer added that over the past several years, Congress has continued to fund nuclear space technology development at NASA "with the goal of conducting a future in-space flight test."
Now, while nuclear electric propulsion has many benefits, especially when trying to get to Mars quickly, there are also risks involved with developing and using the technology.
"The risks associated with [nuclear propulsion] are a fundamental materials challenge that we think is quite likely solvable," Roger M. Myers, the co-chair of the Committee on Space Nuclear Propulsion Technologies, said during the hearing. That materials challenge includes developing or finding materials that can handle exposure to heat and other extreme elements associated with space, Myers added.