The road to Titan

• Instead, in the same gap of time that's passed between Apollo 11 and now, the U.S. could plan and execute a three-year, 745-million-mile journey to Titan, which is replete with the right colony-sustaining resources, experts tell Axios.
• That means a landing date of 2069.
• Reaching Titan is not science fiction: The EU landed a probe called Huygens on Titan in 2005, and NASA is already planning to send a drone there in 2026.

Mars is a good next step, but "Titan should be the keystone for human settlement of the outer solar system, as it has all the materials needed to support life and technological civilization," said Robert Zubrin, a prominent aerospace engineer and space evangelist.

The big picture: Once NASA did a few moon landings, political and popular support for more ambitious projects dried up. Now that backing for big spending has returned, amid a space race among nations and private companies, it's worth scrutinizing just what constitutes a new moonshot.

• The first thing to know is that the Moon has no concrete strategic value: "For the next 20 or 30 years the Moon is just a geopolitical status symbol," Nicholas Wright, a U.K.-based analyst, tells Axios.
• In terms of something big, Mars is a far stretchier goal: NASA plans to send humans to the planet in the early 2030s, and SpaceX is talking about putting a crew in Mars orbit by 2024, though experts are highly skeptical.
• Still, if you are talking long-term human habitation, both of those are just stepping stones, says Amanda Hendrix, a senior scientist at the Planetary Science Institute.

"Neither the Moon nor Mars are ideal for long-term human stays," she said. Titan is "a more sustainable destination."

Not everyone thinks a moonshot to Titan is a great idea: Neil deGrasse Tyson, the astrophysicist, tells Axios' Alison Snyder that he is "not a fan of destination space programs." In an email, he said:

"What would serve multiple interests more reliably and stably in the long run is to create the capacity for robots and people to access space at all levels. Let the needs of the demographic and moment specify what the destination happens to be. Scientists search for life on Mars. Entrepreneurs mine asteroids. Tour companies book trips to orbit and to visit the lunar base, etc. Only then can a space program morph to become a space industry."

In addition, life on Titan would be hard — it's cold (about -290° F) and its atmosphere contains methane, propylene and poisonous hydrogen cyanide, not to mention nitrogen and carbon.

But if you believe that humans respond to specific, difficult-to-reach targets, there is a case for naming Titan as the best next big goal. One main reason is that, unlike the Moon or Mars, astronauts would not have to take everything along to sustain their existence.

• There is a 3,900-mile-long belt of water ice on the Titan surface.
• Its hydrocarbon reserves are hundreds of times greater than the Earth's, providing a source of fuel.
• And the thick atmosphere eliminates radiation as a problem, unlike the Moon and Mars. And its atmospheric pressure is reasonably close to the Earth's, making it easier to engineer the spacecraft and the structure in which humans will live and work.

If you are thinking genuinely long term, there is also the matter of Saturn's reserves of helium-3 — the largest in the solar system, says Zubrin.

• "Helium-3 is the ideal fuel for fusion reactors and fusion rockets, making available nearly infinite energy for an expanding civilization and enabling spacecraft with the ability to achieve our next moonshot after Titan — the reach for the stars."