NASA's '1st nuclear powered interplanetary spacecraft' will send Skyfall helicopters to Mars in 2028

Skyfall is happening, and it will get to Mars in a totally new way.

Last summer, NASA's Jet Propulsion Laboratory and the Virginia company AeroVironment unveiled their Skyfall mission concept, which would send six tiny helicopters to explore the skies of Mars.

Today (March 24), NASA announced that it will develop Skyfall for a 2028 launch, and that the mission will journey to the Red Planet on a spacecraft that uses nuclear electric propulsion (NEP) — what NASA is referring to as "the first nuclear powered interplanetary spacecraft."

NEP systems operate like nuclear power plants here on Earth, relying on an onboard fission reactor. NEP is a fundamentally different technology than radioisotope thermoelectric generators (RTGs), which have powered the instruments of NASA deep-space probes like Voyager for decades. RTGs use the heat of radioactive decay to generate electricity; they are not involved in propulsion.

"Requiring operating temperatures less than nuclear thermal propulsion, the thermal energy produced by the reactor generates electricity, which is then used to power highly efficient electric thrusters," NASA officials wrote in a description of the agency's NEP efforts.

NASA views NEP tech — which can operate at all distances from the sun — as key to its future exploration efforts, from robotic missions to the outer solar system to the operation of a moon base via its Artemis program.

So the centerpiece of the Skyfall mission may not be its fleet of Mars helicopters but rather their interplanetary ride — a spacecraft called Space Reactor-1 (SR-1) Freedom.

"SR-1 Freedom will establish flight-heritage nuclear hardware, set regulatory and launch precedent, and activate the industrial base for future fission power systems across propulsion, surface and long‑duration missions," NASA officials said today in a statement announcing the mission.

"NASA and its U.S. Department of Energy partner will unlock the capabilities required for sustained exploration beyond the moon and eventual journeys to Mars and the outer solar system," they added.

That statement features a wealth of other exploration news and updates. For example, NASA also announced today that it's pausing its long-planned Gateway moon-orbiting space station to focus on building a base on the lunar surface — and some of Gateway's hardware will go into the construction of that outpost.

That statement doesn't reveal many details about the planned Skyfall mission, but AeroVironment gave us some during the unveiling last summer.

"Skyfall is designed to deploy six scout helicopters on Mars, where they would explore many of the sites selected by NASA and industry as top candidate landing sites for America's first Martian astronauts," AeroVironment said in a July 24 statement.

Those helicopters will be similar to Ingenuity, the little NASA rotorcraft that landed on the Red Planet with the Perseverance rover in February 2021. Ingenuity became the first helicopter ever to operate on a world beyond Earth, making a whopping 72 flights between April 2021 and January 2024.

Whereas Ingenuity was a technology demonstrator, however, the Skyfall fleet will have concrete science and exploration tasks.

"While exploring the region, each helicopter can operate independently, beaming high-resolution surface imaging and sub-surface radar data back to Earth for analysis, helping ensure crewed vehicles make safe landings at areas with maximum amounts of water, ice, and other resources," AeroVironment representatives said in last summer's statement. "The data Skyfall collects could also advance the nation’s quest to discover whether Mars was ever habitable."