Why Mars? An Astronaut's Perspective

I have dedicated my life to answering the great scientific questions of our time, and to the incredible adventure of space exploration.

As a young boy growing up on the South Side of Chicago, I was inspired by the nascent space age.  At the age of six I declared that I wanted to be an astronaut.  My mother thought that was just fine, as it would encourage me to learn science, and besides, there really was no chance I would ever actually become an astronaut.  While I watched the Apollo astronauts walking on the Moon, I imagined that I might some day travel to Mars, to do science, of course. Indeed, I felt compelled to study nature, science, and engineering, eventually earning a PhD in physics. As a scientist, I sent experiments to near-space on high altitude balloons as well as into space aboard the Space Shuttle.  But the explorer in me still wanted to go to space in person.  To the amazement of my mother, in 1992 I was selected to become a NASA astronaut.   I had the privilege to fly five missions on the Space Shuttle, including three missions to the Hubble Space Telescope.  I have dedicated my life to answering the great scientific questions of our time, and to the incredible adventure of space exploration. 

Of all the planets in our diverse solar system, Mars is unique in that it is the only planet where we can some day live in a somewhat similar fashion to the way we live on Earth.  It is large enough to have a suitable surface gravity, and has an atmosphere and resources we can use to live off the land. Scientists using the intrepid Curiosity Rover have shown us that billions of years ago Mars was very much like Earth, with fresh water lakes, rivers, and warm salty seas.  At about the same time that Mars was very much a habitable planet, life started on Earth.  Did life also emerge on Mars?  The question of whether we are alone in the universe is for the first time a discrete scientific question we can answer.  We are exploring Mars for signs of past or extant life.  We are also preparing to explore Jupiter’s icy moon Europa, which might harbor a habitable ocean, and with future large telescopes we will look for signs of life on planets orbiting nearby stars.  But Mars beckons us like no other world, and we will exponentially increase the pace of discovery when we have women and men explorers ― planetary scientists and astrobiologists ― on the surface of the Red Planet performing scientific research.  These intrepid explorers will also be opening up a new frontier.

NASA has always been at the forefront of opening the frontier of space, whether with astronauts or robotic scientific explorers.  Our national investment in NASA, pushing the boundaries of science and technology, has a tremendously positive impact on our economy, is critical to our national defense, and has provided inspiration to generations of young explorers.   In the 1945 report Science, The Endless Frontier, which was presented to the President of the United States and which discussed the role of research by the government, Vannevar Bush wrote, “It has been basic United States policy that Government should foster the opening of new frontiers,... [that this] American tradition ...has made the United States great... [and] that new frontiers [should].. be made accessible for development by all American citizens.” This is the grand purpose of NASA, and as suggested by Star Trek,  “to boldly go where no one has gone before” - to open a frontier that is so vast that it defies comprehension, challenges our imagination and forces us to be our very best!

Building on developments from nearly 60 years of space exploration, the dream of sending humans to Mars has never been closer to becoming a reality.  Today there is a convergence of technical readiness, public engagement, and political will that might make a human expedition to Mars possible in the near future.  However, achieving this challenging goal will require leadership, teamwork and focus beyond that seen in the last few decades.  But these traits are exactly what NASA and our nation learned from Project Apollo, the Space Shuttle, and the International Space Station.  The high performance challenge of landing people on Mars and returning them safely will require closer ties between scientists and the engineers developing human systems, closer ties between the U.S. and our international partners, and closer ties between traditional government contractors and emerging entrepreneurial space industries.

When we decide to send women and men to Mars it may well be the highest risk endeavor ever attempted by human explorers. But there is no doubt in my mind that it will be worth the risk.

The essential elements of what we need to go to Mars are at hand. On orbit now is the amazing International Space Station (ISS). This orbiting laboratory is the ideal proving ground for learning what it takes to get to Mars.  Astronauts (and cosmonauts) launch from Earth to a habitat in space.  Their six-month expedition mirrors the time in weightlessness that astronauts will experience on the cruise to Mars.  After their ISS mission, the explorers descend to a planetary surface. It happens to be Earth, but it offers the perfect chance to learn and practice what future Martian explorers will do once they land on the Red Planet.  NASA and its partners must substantially increase the utilization of the ISS, a precious resource, for the purpose of learning how to go to Mars.  Other than radiation, it offers the ideal testbed for technologies and research into human physiology and human factors for the long cruise to Mars.

Sending humans (and all that they will need to accompany them) to Mars will require substantial launch capabilities. This need for heavy launch capabilities goes back more than half a century, thus confirming concepts by Werner von Braun and others for Mars exploration. NASA is investing in the Space Launch System (SLS) to launch its large payloads for its expeditions to Mars.  But there is more than one way to launch such heavy masses into space ― and go to Mars. Indeed, SpaceX and Blue Origin are both investing in their own heavy lift rockets ― and SpaceX plans to start sending its own missions to Mars starting in 2018. One way or another, we’re going to Mars. 

On the robotic exploration front, NASA is building the Mars2020 rover that will continue the exploration of Mars seeking signs of past life in the geologic record and will drill a couple of dozen small core samples for future return to Earth for detailed analysis.  The Mars2020 rover also has an experiment to produce oxygen from the Martian atmosphere ― the first time that resources will have been extracted from another celestial body that are needed to support human exploration. 

NASA is also in the planning stages for a high-power solar electric robotic mission to an asteroid. While I am in favor of learning more about asteroids (as will be done with the recently launched asteroid sample return mission OSIRIS-Rex), the stated driver for the asteroid redirect mission is technology development for Mars exploration.  Redirecting this mission to Mars would allow for significantly more Mars-relevant technology development. It would make possible a first ever round trip between Earth and Mars. Combined with a landed robotic mission in the mid-2020s, this mission would also return the first samples from the surface of Mars.  The high power solar arrays that power the Xenon ion engines can also power a radar which could provide a global map of the subsurface ice on Mars.  This map is required for future human explorers so they can use the ice for water to drink, to produce oxygen to breathe, and for rocket fuel for the return home.  The mission can also provide high resolution imaging and communications ― critical elements for all Mars exploration, human and robotic. A common saying within the military is “amateurs talk strategy, professionals talk logistics.” Overhead imaging, maps, resource reconnaissance and communications are the logistics we need for Mars exploration.  This round trip mission should be regarded as a prerequisite to sending the first human explorers to Mars.

All space exploration is risky.  As an astronaut I had to decide each and every time I went to space whether or not to risk my life for the mission.  When we decide to send women and men to Mars it may well be the highest risk endeavor ever attempted by human explorers.  But there is no doubt in my mind that it will be worth the risk, not only for our own nation but for the rest of humanity as well.  The broad international clarion call to explore the Red Planet is a strong sign that we are ready to try, and the time is now.    

John Grunsfeld is former Associate Administrator of the NASA Science Mission Directorate and served as an astronaut on five Space Shuttle flights.

This piece is part of a special op-ed series, curated in partnership with Explore Mars, in which contributors from diverse fields such as science, education, policy, business and culture answer a simple question: “Why Mars?” For more, follow the links below or visit /exploremars.org/"}}">exploremars.org.