Human exploration of Mars could be feasible in 10 to 15 years, using a revolutionary rocket powered by a nuclear reactor, two NASA experts say.
Stanley K. Borowski and Leonard Dudzinski of NASA's Glenn Research Center, Cleveland, explained the vision Wednesday at a national conference on space propulsion held in Salt Lake City.
The meeting, the 37th joint propulsion conference, was organized by the American Institute of Aeronautics and Astronautics. Speaking or providing displays in the Salt Palace Convention Center were about 80 industry and government groups from space gear companies to rocketmakers, equipment suppliers, aircraft engine manufacturers and software developers. The four-day session ended Wednesday.
Among the huge rocket engines and displays, a stand-out information kiosk was that manned by Borowski and Leonard. Using models, posters and video, they detailed plans for a nuclear rocket that could land astronauts on Mars.
According to plans that the Glenn center is developing, three rockets would be launched to Mars. Two would carry cargo and a living module, while the third would transport astronauts to the planet.
The proposal is called a "bimodal NTR (Nuclear Thermal Rocket) Mars Mission."
What makes this proposal unusual is that each rocket would be powered by a small nuclear reactor, about 36 inches high and half that in diameter. The reactor would heat up liquid hydrogen carried by the rocket, and the hydrogen molecules spewing from the engine would provide thrust.
It would use "relatively near-term nuclear rocket technology that we can develop within the next 10 to 15 years," said Borowski, a nuclear physicist in charge of the center's advanced programs for human exploration.
Supporting that idea was a poster given out at the conference touting a possible cargo mission to Mars in 2016, followed two years later by the launch of astronauts to the "red planet."
"We use nuclear thermal rockets that produce propulsive thrust as well as electrical power," he said. At full capacity, the generators could produce about 75 kilowatts of electricity during the trip, 25 kilowatts more than needed, so they would run at less that full throttle.
In addition, the ship would spin end-over-end to create artificial gravity, which "prevents the debilitating effects of the space environment" on the human body, he added.
Each vessel would be carried to low Earth orbit by two shuttle launches, plus one additional launch for crew quarters used on the astronauts' ship. The segments weigh about 80 tons each. The rockets would be assembled in orbit and then sent on their way.
The cargo ships would be working at Mars before the astronauts took off — a lander and an orbiter.
On the surface, one of the cargo ships provides a habitat for the astronauts and mines the thin atmosphere for the gases that would be used for the ascent back into orbit. The other, to take the astronauts home, remains in Mars orbit until needed.
The nuclear rockets will "provide 15,000 pounds of thrust per engine," Borowski noted. Altogether, each rocket would carry 90 metric tons of liquid hydrogen propellant, divided nearly equally between the two segments.
Dudzinski said nuclear thermal rockets would be about five times as effective as conventional chemical rockets. They work because "the hydrogen is in direct contact with the core" of the nuclear reactor.
The design could allow a fast, one-year trip to Mars and back, he said. The price could be far less than a trip with conventional rockets.
A chemical rocket mission would require about 2,300 metric tons of fuel in Earth orbit, he said. "For the NTR to do the same mission is 480 metric tons.
"So it's about a fifth."
With much of the cost tied up in the price of lofting fuel into orbit, that means nuclear rockets could drastically reduce the price tag.
"In reality, this system is going to cost something to develop a new technology," Dudzinski said. That would add to the cost, he said, but the trip still should be much more affordable than it would be with conventional rockets.