Humans can visit Mars — just not in person
Adozen or so years is not much time to solve a long list of currently insuperable scientific and technological problems. Which is bad news for NASA’s wildly ambitious timetable to begin human spaceflight to Mars by the mid-2030s. Time flies when you’re stuck in low Earth orbit, as humanity has been for nearly 50 years. The International Space Station is approximately 240 miles away — roughly the distance from Washington to New York.
The daunting obstacles between us and Mars begin with the simple problem of weight. A flimsy lunar lander won’t get the job done on Mars. Although it is the most livable non-Earth planet within our grasp, Mars is brutally hostile to life: It is as cold as Antarctica, has less oxygen than Mount Everest, is prone to hurricanes of toxic dust and suffers constant bombardment from lethal radiation. Infrastructure for even the grimmest human existence must be ferried from Earth. Before humans could build housing from Mars bricks or plant crops in Martian soil, they would need brick-making machines and greenhouses. A Mars mission demands vastly more material than humans have ever boosted into space, weight that presents engineering challenges on both ends of the journey. We need larger rockets to escape Earth, heat shields to enter the Martian atmosphere and some sort of braking system to land safely. We have none of these ready yet.
To write that paragraph, I had to gloss over a raft of more complicated challenges. In the absence of sufficient oxygen, astronauts on Mars would probably rely on solar panels to generate electricity for splitting water into hydrogen and oxygen. So add solar panels to the freight manifest. Also ice-mining equipment to recover frozen water from underground. And a high-tech home gym to fight the wasting effects on human muscle and bone mass of long stays in low gravity.
Mars colonists will also need currently nonexistent lightweight materials to shield them from radiation far more deadly than any that can penetrate Earth’s protective atmosphere and magnetic field. As for farming: another unsolved challenge. Topsoil sampled by Mars rovers reveals that a toxic chemical called calcium perchlorate is nearly ubiquitous; this must be neutralized somehow even before the thin, cold dust can be fortified and coaxed into germinating seeds. Far easier to farm Death Valley.
Because of the great distance involved — Mars at its nearest is about 150 times farther away than the moon — a mission to the Red Planet has no room for error. NASA can’t just send more supplies on the next rocket, as is possible at the nearby space station. Thus, it’s not enough to find theoretical solutions to the problems of human life on Mars. It’s not enough even to find good solutions to these challenges. Perfect solutions are necessary — even if the mission is a one-way trip. To send humans and bring them back to Earth is a far more complex proposition.
But technological trends point to a more plausible Martian future. All of the most difficult challenges around travel to Mars stem from a single fact: The human body can’t survive there. The problems of freight and infrastructure; of food, water and oxygen; of deadly radiation — all of it vanishes once you remove the meat from the equation.
The related fields of robotics and haptics are moving rapidly in the direction of hybrid astronauts — machines that can take the human consciousness in real time to another planet.
While humans have been stuck in low orbit for half a century, robots have been working miracles in space. NASA probes have been exploring Mars for decades; the latest mission, launched this year, is designed to scoop soil samples into sealed containers for future collection and return to Earth. In recent years, robots have landed on a comet, sampled an asteroid, visited Jupiter and flown beyond the solar system.
Haptics is the field of computer science that develops data into human sensation — the feeling of touching something a robot touches, of seeing through a robot’s eyes, of hearing what a robot hears. It’s inevitable that the convergence of robots and haptics will produce in the nottoo-distant future interplanetary probes that allow humans to visit other worlds, to “touch” and “see” them, via hardware on the surface and software in the ether.
“Future exploration of planets will most probably involve robots that are controlled by humans orbiting the planet above,” a blog of the European Space Agency predicts. Though complex, traveling into orbit around Mars would be far simpler than a landing. Engineers can also work on ways to speed data from robots on Mars to humans on Earth.
Exploration is human nature — but so is the use of tools. Let’s be smart and build tools to take us to Mars without the likelihood of dying there.