The human journey to Mars will be a great adventure, the greatest of our age. No destination is more exciting, and none more difficult. Mars is very far away, much further than the Moon. A round trip takes years—years in which you have to supply food, water, and oxygen for astronauts, all while minimizing radiation damage, health issues, and even boredom.
But difficult is not the same as impossible.
We have most of the technical knowhow and ability to pursue this adventure if we so choose. The central challenge bedeviling human exploration of the Red Planet is far more prosaic: cost. Various concepts for sending humans to Mars have ranged into the hundreds of billions of dollars—far beyond what NASA, which currently occupies 0.4% of the federal budget, can handle. (Read Buzz Aldrin's plan to get to Mars.)
Our organization, The Planetary Society, recently convened a high-profile workshop in Washington, D.C., with experts from NASA, private industry, and the scientific community to examine this problem. Is there a sustainable, affordable, and realistic program to get humans to the surface of Mars and back? We think there is, and we call it orbit-first.
Orbit-first is straightforward. Instead of landing on the first mission to Mars, why not just focus on getting to Mars orbit instead?
There’s lots to do up there doesn't require getting humans on Mars: landing on one of the Martian moons, driving rovers on the surface, and testing all the new hardware and systems required before we attempt landing. Crucially, this plan also lowers the initial cost of developing the new hardware, which should be minimal with NASA’s new Space Launch System rocket and new crew capsule coming online within the next few years. (Read about astronomers recently finding a long-lost ocean on Mars.)
The centerpiece of our workshop, which is also being presented Wednesday at the Humans to Mars Summit in Washington, D.C., is a concept developed by a small team at NASA’s Jet Propulsion Laboratory (JPL). It features a visit to the Martian moon Phobos by a crew of four astronauts leaving in 2033, a date set by the time required to develop the hardware without busting the budget, but also by orbital mechanics.
Every 26 months, Earth and Mars are aligned in their orbits in such a way that minimizes the fuel requirements to travel from one to the other. Any spacecraft traveling from one planet to another must obey this schedule.
Travel each way takes about 7 months, and since you have to wait for the special alignment of the two planets to get back to Earth, the astronauts would stay in orbit or on Phobos for over a year before returning home. Follow-on missions would begin landing on Mars by 2039, greatly benefiting from the experience gained by orbiting first. (Read about the missing spacecraft found on Mars after an 11-year search.)
There are many details to work out, but the team was able to do a quick sanity-check on cost. They had an independent company examine their program and conclude that it could be done for roughly the cost of the current human exploration program at NASA, as long as it keeps pace with inflation. Crucially, this assumes that NASA divests from the International Space Station as planned in 2024, which would free up about $4.5 billion per year to be used for Mars. That’s currently less money than the postal service loses annually.
The orbit-first mission plan is the most affordable concept for a human mission to Mars that we know of. Again, while many details will change as the idea evolves, the overall concept and cost was judged as plausible by the experts at our workshop.
There are great opportunities for science by landing on Phobos and operating rovers on the surface. And it would engage the public. Just think of the adventure of four astronauts catching a sunrise from the surface of Phobos, or the thrill of their view of Mars from above. The whole world would be with them, exploring in spirit on the most daring adventure in human history.
If Mars is the goal for human spaceflight—and we believe it should be—then we must establish a plan to get us there that adheres to realism in cost. The orbit-first approach minimizes risky new technology, maximizes return on the investments of existing hardware, and would enthrall all of humanity with the grandest adventure since Apollo
Editor's note: Bill Nye is chief executive officer and Casey Dreier is director of advocacy at The Planetary Society.