Ex-NASA Space Shuttle astronaut has a plan to get humans to Mars fast

Ad Astra’s VASIMR engine is built to cut Mars travel times

The ultimate goal for Costa Rica and U.S.-based Ad Astra is to make much faster, but also much safer, spaceflight possible. To do so, it's developing its VASIMR VX-200SS plasma rocket engine, which it hopes will one day be powered by a small nuclear fission reactor designed specifically for spacecraft.

That reactor will provide enough electricity to power the VASIMR engine, which will fire burning plasma out of a nozzle, blasting the rocket through space at speeds of up to 123,000 mph (197,950 km/h). 

At those speeds, a spacecraft could reach Mars in roughly 45 days, meaning it would cut existing travel estimates sixfold — NASA estimates it would take around seven months for a human-rated spacecraft to reach the red planet with existing technologies. And it's no pipe dream, Chang-Díaz explained.

Ad Astra's VASIMR engine, which stands for Variable Specific Impulse Magnetoplasma Rocket, was designed to eventually use the power from a nuclear fission reactor to heat plasma to two million degrees. Once the gas reaches those temperatures, hot gas is then channeled using magnetic fields, allowing the engine to power a Mars-bound rocket.

Before it can send its plasma engine to deep space, however, Ad Astra will first have to test it in orbit. And it will likely have to start off powering its high-power electric VASIMR engine with sunlight for more local missions.

Getting the VASIMR plasma engine off the ground

Back in 2021, Ad Astra completed a record 88-hour high-power endurance test of its VASIMR VX-200SS plasma rocket at 80 kW. That marathon endurance test "demonstrated that the VASIMR engine is able to operate pretty much indefinitely at high power," Chang-Díaz told IE.

"It moved the technology from technology readiness level (TRL) four to five, and to borderline level six," he explained. "Our goal now is to transition the technology into flight readiness."

TRL level six would involve a space demonstration of the VASIMR engine, and it would bring it one vital step closer to the final deployment stage. Once deployed, Ad Astra aims to first utilize VASIMR for applications closer to home, such as moon logistics missions.

To start with, "we will probably deploy 150-kilowatt engine modules that will be broadly solar powered," Chang-Díaz said. "Logistics is becoming a really important element in making sure that the space economy thrives and evolves quickly. And that means you need heavy-duty transportation."

"I make the analogy of developing the diesel engine of space, [like for vehicles on Earth] that carry big rigs," he continued. "Nowadays, of course, diesel is not such a popular thing, but we need high-power, electric propulsion and that’s the niche we’re trying to fill."

The next big step for Ad Astra would then be to utilize nuclear reactors that will generate electricity, not thrust, Chang-Díaz emphasized. "There is the nuclear thermal approach to nuclear propulsion, but we don’t believe in that," he said. "We’re aiming to utilize the nuclear electric approach — [and] getting to Mars is the big payoff."

"We want to be able to do a Mars mission with 40 to 50 megawatts of electricity from a nuclear reactor," Chang-Diáz explained. "Our calculations say this would allow us to propel a 70-metric-ton delivery payload to Mars in 95 days. And this timeline will get shorter as the technology gets better."

One hurdle Ad Astra must overcome is the funding of its ambitious rocket engine. "The timeline for when we’ll see a VASIMR demonstration in space is all dependent on the funding," Chang-Díaz said. "Right now, to get this engine ready to fly, we're going to need something on the scale of $150 million. To launch it to space we'd need maybe another $50-60 million." If that investment were secured now, "we could see this engine flying three years from now." Until that happens, however, "everything else will continue to inch along."

A former NASA astronaut's perspective on flying to Mars

As a former NASA astronaut, Chang-Díaz brings a unique perspective to his role as founder and CEO of Ad Astra. In 1980, he was selected as the world’s first Hispanic NASA astronaut, having acquired a Doctorate in Applied Plasma Physics from MIT in 1977. He went on to log over 1,600 hours in space — including 19 hours performing spacewalks — across seven Space Shuttle missions before his retirement from NASA in 2005.

The space veteran would have loved to have gone to Mars. "In fact, when I first became an astronaut," he told IE. "We all thought we were at least going to go to the Moon, and that was 1980 — it was a long time ago." Now, thanks to his work with Ad Astra, he may help a new generation of astronauts to go far beyond the moon and into deep space.

Taking humans to Mars, however, will involve a lot of moving parts, machinery, and, crucially, two moving planets whose orbits periodically set them great distances apart.

As Chang-Díaz pointed out, "the planets are in cyclic movements around the Sun," and this "plays into [a Mars mission] in a big way. If it takes the better part of a year to get to Mars, then when you get there, the Earth is going to be on the other side of the sun. So, you'll have to wait until the planets are more or less aligned again to jump back. That could take another year."

Aside from that substantial logistical issue, the Ad Astra founder said, Mars astronauts will also face the problem of "radiation and the exposure to weightlessness," as well as all the issues of "logistics, supplies, and food" that will have to be organized.

That's why nuclear propulsion holds the key. "For me, this is the one thing that needs to be done for humans to go to Mars," Chang-Díaz said. "That is the homework that has not been done, that should have been done half a century ago. But it's not too late."

The Overview Effect inspired Ad Astra's renewable energy efforts

The Ad Astra CEO's time in space had a great impact on his worldview and on the company, he decided to build after retiring from his NASA duties. The former Space Shuttle astronaut told IE that he experienced the well-documented Overview Effect, which sees space explorers undergo a perspective-altering cognitive shift after seeing the Earth from afar for the first time.

Astronauts tend to "become much more focused on the planet and on planetary dynamics, rather than the dynamics of the local community they came from or the country they came from," he said. "We’re no longer really citizens of a country, we’re citizens of a planet."

"When you're out there, the Earth is in front of you in its wholeness, and it's unavoidable to see the planet as a whole and not realize that we are all really astronauts, we are all really crew members in this tiny little spaceship, and we're really messing up our life support system."

That life-altering experience played a large role in the work Chang-Díaz is now carrying out with Ad Astra. "I tell people that the most important system in a spacecraft for astronauts is the life support system," Chang-Díaz continued. "If that thing doesn’t work, you die. But we’re really messing up our life support system on Earth and don’t seem to be too worried about it in our daily lives. So that's my perspective as an astronaut; you have to keep that life support system in good shape."

That sentiment goes a long way toward explaining why Ad Astra is also working on renewable energy technologies for Earth. The company's hydrogen solutions were, in fact, partly inspired by NASA's Space Shuttle, which housed three fuel cells to provide power for the crew's life support system.

Crucially, Space Shuttle astronauts also combined oxygen with the hydrogen from the fuel cells to generate drinking water.

"I was impacted by that because that's the kind of thing that we need to do here on Earth," Chang-Díaz said. "And so in our facility here in Costa Rica, we are basically implementing that same ecosystem for hydrogen production from the electrolysis of water, using renewable energy — sun, wind, and hydroelectric."

"The sun is sending us huge amounts of energy, every single day, all over the planet," he continued. "Most of it, we just let it go by and we don't even use it. And then we have an energy crisis. We're digging holes in the ground to get natural gas and petroleum. We're just polluting our atmosphere instead of using all this energy that's coming to us, reliably, every single day."

With his experience as an astronaut serving as a guide, Chang-Díaz hopes to develop solutions that can save our planet while also building toward a long-term future where we can also rely on our nearest planetary neighbors — those tiny spaceships — as life support systems for humanity.