Our Ticket to Mars?

NASA, DARPA plan to launch nuclear-powered spacecraft

It might be another 15-20 years before astronauts go on a mission to Mars. But by the time that mission goes, NASA and the Defense Advanced Research Projects Agency plan to make the 300-million-mile journey a quick one. They’re counting on nuclear thermal propulsion to help them do it. The nuclear-powered spacecraft they’re developing in partnership with Lockheed Martin is called DRACO (Demonstration Rocket for Agile Cislunar Operations), and it could go into orbit around Earth by late 2025.

“We’re going to put this together, we’re going to fly this demonstration, gather a bunch of great data and really, we believe, usher in a new age for the United States, for humankind, to support our space exploration mission,” Kirk Shireman, vice president of Lockheed Martin Lunar Exploration Campaigns, said.

With current technology, it would take about seven months for a spacecraft to reach Mars. A nuclear-powered spacecraft could cut that time in half or better. That isn’t just to spare astronauts a bit of boredom as they hurtle through space.

“If we have swifter trips for humans, they are safer trips,” NASA deputy administrator Pam Melroy, a former astronaut herself, said.

That’s because of the amount of solar radiation astronauts will be exposed to on the journey. The high radiation levels could affect astronauts’ brains, impairing their memories and ability to learn and causing mood swings. Needless to say, those are not things you want on a long journey in space and when conducting scientific experiments on the surface of an alien planet.

In the Works

The nuclear thermal propulsion on DRACO could prove to be two to five times more efficient than the chemical propulsion spacecraft currently in use. NASA has had designs on nuclear-powered spacecraft as far back as the 1950s and even planned a Mars mission for 1979 before the Nuclear Engine for Rocket Vehicle Applications (NERVA) was scrapped in 1972.

For DRACO’s reactor and fuel, Lockheed is partnering with BWX Technologies. DRACO will go into a high orbit between 435 and 1,240 miles above Earth leaded with 4,400 pounds of cryogenic liquid hydrogen for propulsion that the fission reactor, which won’t activate until the craft reaches those heights, will transfer heat to. The orbit is high enough that it will take at least 300 years for atmospheric drag to bring DRACO’s demonstrator back to Earth, long enough for all the fuel to be spent by the time it returns.

“The ability to accomplish leap-ahead advances in space technology through the DRACO nuclear thermal rocket program will be essential for more efficiently and quickly transporting material to the Moon and eventually, people to Mars,” DARPA director Dr. Stefanie Tompkins said.

NASA and DARPA set a launch goal of 2027 before revising the timeline to late 2025 or early 2026.

First, the Moon

Before the agencies endeavor to send a nuclear-powered spacecraft loaded with astronauts to Mars, they’ll set their sights a bit closer to home. DRACO’s first focus will be transporting material quickly and efficiently in the cislunar domain, the space between Earth and the moon. Once it proves itself, then taking people to Mars will become the target.

“Working with DARPA and companies across the commercial space industry will enable us to accelerate the technology development we need to send humans to Mars,” Melroy said. “This demonstration will be a crucial step in meeting our Moon to Mars objectives for crew transportation into deep space.”

There will be a lot of activity in that cislunar space soon, with construction of the Lunar Gateway space station beginning in the next couple of years and humans returning to the surface of the moon for the first time in more than five decades.

Nuclear power is set to play a key role, with the UK Space Agency investing millions in the development of a lunar nuclear reactor that could support human exploration on the moon, lengthening those missions and increasing the scientific value derived from them.

NASA is working on other nuclear technology projects with a variety of partners. That work includes other designs for nuclear thermal spacecraft.

“Through NASA’s prior investments – in collaboration with the Department of Energy – we’ve supported the commercial sector to grow their capabilities in nuclear propulsion technology,” said Dr. Prasun Desai, acting associate administrator for NASA’s Space Technology Mission Directorate. “Now, those investments are coming full circle as we work with these same companies to build the first nuclear-powered rocket to fly in space.”