Contenders for the Moon and Mars
The march of interplanetary progress
In March 2020 NASA began accepting applications for future astronauts for the first time in more than four years, and more than 12,000 people applied. The call went out as the space agency prepared to send the next man and the first woman on a mission to the Moon by 2024, a necessary precursor to the next giant leap for humanity: sending astronauts to Mars…
It’s one of the ironies of history that a description of humankind’s greatest adventure of the entire 21st century includes a blatant understatement: Applicants should have a willingness to travel and not be afraid of heights. Those who read the complete NASA press release in 2015 quickly realized that a master’s degree in a biological science, engineering, or mathematics would be needed and either two years of relevant professional experience or 1,000+ hours of pilot-in-command time in a jet aircraft. What NASA was looking for as part of its mission to visit and ultimately settle Mars was demonstrable competence. And now after years of intensive preparation the departure date is drawing closer, and some members of the current class of astronauts may well be on board the first manned flight to Mars. “NASA is embarking on an ambitious journey to Mars, and we are looking for talented men and women from diverse backgrounds and every walk of life to help get us there,” said then– NASA Administrator Charles Bolden. But what exactly will be involved? What can the astronaut candidates expect? And which skills are likely going to be essential for a successful mission?
THE ADVENTURE BEGINS…
When the NASA Perseverance rover landed on Mars on February 18, 2021, it had traveled nearly 300 million miles over 203 days through the vacuum of space at temperatures that averaged – 455°F to get there, which should be sufficient evidence that for any living being, space is a potential death zone.
Contrary to popular opinion, though, exposure to the conditions of space would not cause a person to freeze or explode on the spot. For one thing, heat transfer is not as rapid when it occurs by way of radiation alone in the absence of air. However sudden decompression could rupture the lungs unless the air in them could be immediately exhaled. Then a lack of incoming air would be compounded by the fact that oxygen diffuses out of the bloodstream in a vacuum. That would quickly lead to deprivation and precipitate unconsciousness within 15 seconds. Data from accidents and animal experiments have suggested a person could not survive for much more than a minute after that. NASA, of course, will do everything it can to prevent any such occurrences.
HAZARDS OF HUMAN SPACEFLIGHT
In its publications the agency is quite open about the hazards of space and the journey to Mars, which it admits “offers an inexhaustible number of complexities.” It groups the hazards into five categories. The first of these is radiation, which is considered one of the most menacing because it is invisible to the human eye. Here on Earth we are largely protected from radiation due to the atmosphere, but there is no such protection in space. Excessive exposure to radiation can damage the central nervous system and cause behavioral changes as well as raise the risk of developing cancer. Astronauts on the International Space Station (ISS) are exposed to 10 times
more radiation than on the Earth, and deep space is much more dangerous. Thus vehicles traveling to Mars need heavy protective shielding and must be equipped with dosimeters and an alarm system to warn the astronauts of unexpectedly high radiation levels. Research is also under way to develop pharmaceuticals that can help defend against this hazard.
Yet another significant issue is the confinement experienced by a small group of astronauts traveling together for many weeks or months in a small module. NASA has always carefully selected its crews and trained them to work effectively as a team, but the Mars astronauts will be more isolated than any who have gone before them. NASA is developing tools for matters related to confinement and isolation, including such aspects as workload and performance, and light therapy may help with circadian adjustments. A third hazard is the sheer distance from Earth and the length of travel it entails. Instead of a three-day trip to the Moon, Mars astronauts could be far from their home planet for years. The ISS has provided important data on the experience of being away from Earth for prolonged periods. But the proximity of the ISS means a crew can be brought home relatively fast in a medical emergency and can be constantly resupplied from Earth with any food and equipment they need. On a journey to Mars, however, there is no resupply—and no turning back. Mars astronauts will have to respond to any situation, no matter how dire, without material support from Earth.
“NASA is embarking on an ambitious journey to Mars, and we are looking for talented men and women from diverse backgrounds and every walk of life to help get us there.”
Once the astronauts have arrived at their destination, they will have to learn to live and work in a completely new and different environment. After living in the weightlessness of microgravity on the outbound journey, the astronauts will discover the force of gravity on Mars is only two-fifths of that on Earth. And having adapted and survived in this new environment over a period of months or years, then the astronauts will have to adapt once again on their homeward journey and yet another time when they’ve finally made it home. Their bones, muscles, and cardiovascular system will face a period of serious readjustment after years away from the Earth’s standard gravitational pull. The final hazard on NASA’S list involves technology. The spacecraft that takes the astronauts to and from Mars must be a fine-tuned machine that creates an environment with the right temperature, pressure, lighting, and amount of room along with the food, sleep, and exercise the astronauts require to be healthy and happy throughout their long journey. Some data points will be contributed by the astronauts in the form of urine and blood samples, but they will also provide feedback about sensations and impressions they experience so necessary adjustments can be made.
COMPETITION IS GROWING
To many Americans NASA is the most familiar name when it comes to space, though a number of competitors have arrived in recent years. February 2021 saw not only the landing on Mars of NASA’S Perseverance rover but two other robotic space missions as well: The Emirates Mars Mission arrived first on February 9 and was followed one day later by China’s Tianwen-1. “There’s an incredible amount going on,” says Bruce Jakosky, a professor in the department of the geological sciences at the University of Colorado Boulder and the associate director of its Laboratory for Atmospheric and Space Physics (LASP). He is also one of the authors of a NASA report on the priorities for future science in space. “We are looking at several years of truly exciting Mars science,” he says. He believes these robotic space missions will shed some new light on how the planets formed and evolved and may lay the groundwork for us to visit them.
A human mission to Mars has long been a NASA objective, and several of the experiments carried out by the Perseverance rover will undergird it. The Mars Oxygen In-situ Resource Utilization Experiment (MOXIE), a device about the size of a toaster, has already turned small amounts of Mars’s carbon dioxide atmosphere into oxygen. An expanded version may one day be used to make enough oxygen for astronauts to breathe and rockets to put to use for combustion. Because large amounts of propellant would be needed to launch the Mars astronauts on their homeward trip, other research must identify Martian resources that could be used for fuel. Thus Perseverance was equipped with the Radar Imager for Mars Subsurface Experiment (RIMFAX), a radar instrument that can “see” below the surface crust. There is evidence of large subsurface ice deposits on Mars, which might be used to create fuel. The Perseverance rover is also carrying samples of potential spacesuit materials for astronauts. These will be tested with the Scanning Habitable Environments with Raman & Luminescence for Organics & Chemicals (SHERLOC) to determine how well they can resist the surface conditions on Mars. If it all sounds very complicated, well, it is! But as President John F. Kennedy once said, we don’t do these things “because they are easy, but because they are hard.” The journey to Mars will be the hardest thing that humankind has attempted thus far in its history (with the possible exception of coexisting in peace), but NASA, with the help of its national and international partners and in competition with a growing number of other agencies, appears to be on the right track to get there.