How we'll get to Mars — what's the biggest challenge, money or technology?

This story is Part 1 of Quirks & Quarks' Pathway to Mars series. Each instalment will look at one part of the huge challenge of the most ambitious journey of exploration we've ever attempted — a human mission to Mars.

There will be many steps on the pathway to Mars. It's a vastly more complicated effort than just putting astronauts on top of a big rocket. 

An intimidating list of new technologies will have to be developed to get humans to the red planet — and to allow them to survive once they get there.

But the biggest challenge might be paying for the trip. This will be the most ambitious and expensive journey of exploration ever, and we have to figure out how to accumulate the political and financial capital we'll need to pay for such a huge endeavour.

Dr. Robert Thirsk, a Canadian astronaut who spent more than six months on the International Space Station in 2009, has given a great deal of thought to the technical side of this.

"There are a number of critical technologies that have to be assessed and tested before we go to Mars," he told Quirks & Quarks host Bob McDonald.

His short-list includes reusable landers, new space suits, mining gear, water and fuel production plants and safe nuclear power sources that could be used to power habitats and equipment on the red planet.

Thirsk himself is currently working with the Canadian Space Agency to investigate the unique biomedical and health care issues involved in long-term deep space missions.

Lindy Elkins-Tanton, the Director of the School of Earth and Space Exploration at Arizona State University, has another perspective on the technical challenge. There's so much work to be done that this is going to be a massive human, as well as technological, effort. 

"It's going to take every discipline of human endeavour, and it's going to take all of our economic sectors, not just government, not just private sector," Elkins-Tanton says. "We need the universities, we need the rest of society, we need everybody involved if we're going to make this happen." 

First, you build the rocket

If the rocket isn't the only technological hurdle, it's still the first one, according to Elkins-Tanton.

"That's number one. What's the rocket? We've got to get enough mass up off the planet and going fast enough that it can go out to Mars," she says.

That is where private enterprise, in particular Elon Musk's SpaceX, may figure prominently. SpaceX has already demonstrated the ability to launch more cheaply than its competitors. And Musk has ambitious plans for the future as his recent tests of his giant Starhopper rocket prototype illustrate. It could be the developmental path that will lead to a Mars rocket, though NASA and other private space flight interests are developing their own systems.

SpaceX Starhopper test flight in Boca Chica, Texas, in August

Prospecting for water 

In the meantime, Elkins-Tanton says we will need to work on some of the technologies we'll need to survive on Mars.  One critical question is water. "We really can't bring with us all the water that we need."  

Drinking water will be critical for astronaut survival, of course, but would also be a valuable resource for making rocket fuel on Mars. Solar or nuclear energy could be used to split the water into combustible hydrogen and oxygen. That would mean a mission wouldn't have to carry all the fuel for it's return all the way from Earth, which would be a tremendous savings in launch costs.

Elkins-Tanton says the raw material shouldn't be an issue.

"There is water on Mars in the form of ice in rocky glaciers closer to the equator and then in polar caps that are harder to reach," she says.

Extracting this water would be a substantial task, but she says companies like heavy equipment manufacturer Caterpillar are working to imagine what mining equipment would look like on Mars.

We'll also need to think about things like communication and navigation.

"There are groups working on how we keep track of locations, and we have the GPS network here on Earth, but we don't have those for the moon and Mars," Elkins-Tanton says.

Is the moon on the way to Mars?

NASA is currently planning for a return to the Moon, in part as a practice mission for Mars, says Elkins-Tanton.

"We have to be a lot more certain about our technology before we're ready to go to Mars, and we can at least practice with the technology a little closer to Earth," she says.

Humans haven't walked on the Moon since 1972. At this point, NASA hopes to return in 2024 with a series of missions called the Artemis lunar exploration program.

The first of the planned Artemis missions will be orbiters, the first unpiloted and the second crewed, as NASA tests its new Space Launch System rocket and Orion spacecraft. A mission aimed at landing would follow. The timetable for the missions may be ambitious however, as both of these programs have faced schedule and budget issues.

No bucks, no Buck Rogers

This last point raises a critical issue. Rockets run on fuel, but space programs run on money, and the cost of a trip to Mars will be, appropriately, astronomical.  

Christian Davenport, who covers the defence and space industries for The Washington Post, says that because of the amount of new technology that has to be developed, it's hard to calculate even a theoretical budget for a Mars mission. The best guess would certainly be in the hundreds of billions of dollars.

This is something, he says, that NASA just doesn't talk much about.

"The space agency is really nervous about saying out loud and in public how much it would actually cost because it would just make members of Congress run away in fear," he says.

The tremendous cost and scale of a mission is likely to make international co-operation for a Mars program a necessity.  But one wild card is the current tension in U.S.-China relations. 

China's ambitious space plans include the first ever landing on the dark side of the Moon in 2018

Davenport says China has made enormous strides in its space program and is likely to be one of the most ambitious space-faring nations in the future. 

"A lot of people think that if we're going to be able to pull something off like going to Mars the [U.S. and China] need to work together," he says.

All this makes Davenport suspect that timelines often bandied about that suggest a human landing on Mars as soon as 2030s are unlikely.

"Getting to Mars in that tight of a timeframe without a clear plan, without the funding, without these alliances, just seems like it's incredibly ambitious."

Space scientist Elkins-Tanton is still optimistic, though.

"I think the chances that we do it in our lifetimes are very high," she says. "It would change everything about how we think about who we are."

Next month, in Part 2 of our Pathway to Mars series, we'll delve more deeply into the development of the giant, powerful rockets we'll need to get to Mars.