Technology | Space | Illumination | Editorial
Moon or Mars? Where Are We Going?
As NASA strives to return humans to the Moon by 2024, a trio of robots is about to pull off a Martian hat trick.
Space cognoscenti have long debated the appropriate next big destination for human spaceflight — Mars, or the Moon.
In the next couple of weeks, three robotic missions are poised to take advantage of the current favorable alignment in Mars and Earth’s relative positions, which occurs every twenty-six months. The last such window occurred in May 2018 when NASA launched the Mars Insight mission.
Now, scientists and engineers from the United Arab Emirates, China, and the United States are set to launch the latest explorers in advance of what some think should be the primary focus of human space flight — Mars. Meanwhile, NASA and its industry and international partners continue to develop and test other robot explorers, a new space capsule, and a giant, human-rated rocket destined for the Moon.
The Emirates Mars Mission, which will be launched on a Japanese H-2A rocket from Tanegashima Space Center in Japan, will orbit the red planet and study the dynamics of its atmosphere, in the United Arab Emirates’ first mission to Mars. China’s first attempt at landing on Mars will begin when a Long March 5th rocket lifts off with the Tianwen 1 robotic mission that includes an orbiter, a lander, and a rover that will explore the Martian surface. As part of its long-term robotic exploration of the Red Planet, NASA will launch the Mars 2020 mission with its Perseverance rover from Cape Canaveral, Florida, aboard an Atlas V rocket.
Not a Galaxy, But Far, Far Away
All three missions arrive at Mars in February 2021 after interplanetary journeys of about seven months, highlighting the almost unimaginable distance from Earth to Mars, 54.6 million kilometers at their theoretical closest approach. Since spacecraft follow curved rather than straight-line trajectories, the distance traveled is much longer. The real killer, especially for potential human missions, is the flying time required to get to Mars and return. Human missions could last two years or longer.
One reason three robotic missions are all launching this summer to leverage the favorable planetary alignment is the current limited state of propulsion technology. Add the mass to accommodate astronauts (or cosmonauts, taikonauts), keep them alive and healthy, and return them to Earth in a reasonable time, and the problem becomes more acute. Even with current technology, we can get to the Moon or back in three days.
The journey to Mars will include other dangers. Radiation from cosmic rays can perhaps be mitigated but at the cost of spacecraft weight, complexity, and, well, cost again. We do not yet know the full effects of prolonged weightlessness, or psychological issues from isolation. How would the astronauts and ground crews deal with potential medical emergencies that might include surgery?
And that’s just for the journey. While arguably the most Earth-like planet in the Solar System, Mars is a toxic, hostile place for humans.
Sending humans to Mars any time soon is, at best, of questionable engineering, physiological, economic, and political feasibility, certainly in the next ten years. A massive, focused, and international program, a sort of “Apollo for Mars,” might do it at tremendous expense. While sending humans to Mars is an appropriate long-term aspiration, something we ought to plan to achieve one day, it is unreasonable to expect it to happen anytime soon. Mars is too hard, too far, and too expensive.
But even if we collectively decided to do so, followed through with the requisite public-private and long-term international effort, and made the journey, say in the next twenty years, what would we do then? We would already be stretching the limits of technology and human endurance. At best, we’d send a minimal crew to plant some flags, walk around, do some arguably very costly science, and come home. A significant first step, a start for sure.
The reality is that decades would pass before establishing any meaningful infrastructure to support a sustained human presence on Mars.
Sending humans to Mars, before we know what we’re doing in deep space, would be in effect a “flags and footprints” stunt for the foreseeable future. Setting challenging goals is one thing, but setting virtually impossible goals and placing them decades in the future is a recipe for the political dithering we have seen regarding space in the half-century since Apollo’s success.
Our Backyard
How long has it been since we’ve been back to the Moon? Yeah, remember that? Nine Apollo missions got to the Moon’s vicinity, and of those, six got to the lunar surface. More than a half-century too soon, one could argue. We weren’t quite ready — technologically, economically, and, most important, politically. We didn’t have the political will to follow the achievement of John F. Kennedy’s goal of “landing a man on the Moon and returning him safely to the Earth,” with the establish a permanent, sustainable presence. Political support for Apollo was not as strong as many people think.
It is not certain we have the will to return to the Moon now. Vice-President Pence says we’re going back to the Moon by 2024, perhaps improving President Obama’s dismissive declaration regarding the Moon, “We’ve been there before. Buzz has been there.” Meanwhile, President Trump loudly shouts, “Very soon we’re going to Mars.” Despite renewed enthusiasm among proponents, the significant delays and cost growth in the flagship Space Launch System and Orion spacecraft that were supposed to return humans to the Moon several years ago are disappointing and maddening.
Yet, the Moon and the space between the Earth and Moon, or cislunar space, will be an excellent training ground for future human deep Solar System missions, like going to Mars. The development of in-space infrastructure and systems there will facilitate such activity.
Simultaneously, unleashing the power of real commerce in space — extracting valuable resources and making stuff there for use in space or on Earth — can grow a robust cislunar economy. Morgan Stanley’s Space Team estimates that the roughly $350 billion global space industry could surge to over $1 trillion by 2040.
Overemphasizing Mars in the near term ignores the reality that the Moon is close, interesting, and useful, as pointed out in the work of the late Dr. Paul Spudis and his book The Value of the Moon.
So why this summer’s emphasis on sending multiple probes to a planet that is so far away, at the edge of likely human spaceflight capability in the next decade or two or maybe three, even if we spend billions to make it happen? Why not a sharper focus on human space activity in our backyard before setting off on the admittedly exciting but risky long road trip?
This month’s Mars probes leaving Earth from three different nations are an exciting and essential continuation of space exploration and promise tremendous scientific returns in their own right. And they will bring us a tiny bit closer to eventually sending people to Mars.
Meanwhile, let’s get serious about getting humans back to the Moon and setting up a collaborative cislunar world. There is reason to go fast — to establish and maintain momentum to counter inevitable political slow rolling. There is nothing like a deadline to instill urgency of effort and tangible progress — for a realistic goal.
