A manned mission to Mars is being discussed more seriously than ever before, thanks to the interest of President Donald Trump — who used his inaugural address to promise an American flag on the Red Planet — and the immense influence of longtime Mars enthusiast Elon Musk. Musk himself said in September that his company SpaceX will send manned missions to Mars as early as 2028. NASA’s current timeline is sometime in the 2030s, after a manned mission to the moon that the agency hopes to pull off in mid-2027. Musk’s priorities, though, could become NASA’s priorities. The confidante of Trump plays an outsize role in government, and NASA administrator Jared Isaacman has close ties to SpaceX. In a January tweet, Musk called the moon a “distraction,” and wrote “we’re going straight to Mars.” In a separate February tweet, Musk appeared to link cancelling the International Space Station with focusing on a Mars mission. Just one problem: Humans still have to survive the trip, survive the landing, and get back. And the faster NASA tries to plow through planning, the less likely it is that anyone will be alive once they open the hatch and take their first steps on Mars. “You can send people to Mars with a whole bunch of unknowns, and that's all risk to the mission being successful, the crew surviving,” Deputy Associate NASA Administrator Nujoud Merancy, who helps lead NASA efforts for a moon and later Mars mission, told DFD. As millennia of explorers can attest, it’s sometimes easier to build a vessel than to manage the safety of the human cargo inside. Humans going to Mars face a set of risks considerably larger than the ones they took going to the moon, a trip that took three days and never got further than a few hundred thousand miles from earth’s surface. Mars has never been closer than about 34.8 million miles from Earth in recorded history — which means astronauts will be signing onto a round trip journey of around three years, according to NASA. Figuring out what could happen to them, and how to protect them along the way, is a puzzle that space experts are just starting to sort out. Among the hardest problems for NASA is predicting the exact impact of deep space radiation on astronauts, which has the potential to kill or sicken them both in transit and on Mars’s surface. On the journey, astronauts will face two types of radiation — solar radiation, which is easier to shield from, and galactic cosmic rays, which are harder to protect astronauts from. NASA has worked on ways to shield from cosmic rays, but the particles, moving at near the speed of light, can pass easily through normal spacecraft. To try to model the problem, NASA runs experiments using a galactic cosmic ray simulator at Brookhaven National Labs, which can replicate deep space radiation. It also can rely on a host of Earth-bound analogs related to historical instances of humans being exposed to radiation. One study is looking at the impact of radiation treatment on patients by looking at the effect of radiation on non-cancerous cells as an analog for the sorts of indirect radiation exposure astronauts might face, said Steven H. Platts, the chief scientist for NASA's Human Research Program. Another looks at the effect of radiation on U.S. Navy submariners, based on their long-term proximity to their submarine’s reactor. Data collected on the survivors of the Hiroshima and other nuclear bombings is yet another large source of information. And Mars itself is its own wild card. “We won't really know about the radiation environment on Mars until we're on Mars,” said Platts. Pack a lunch: Astronauts will also need to eat — but rockets have limited capacity to carry the two thousands pounds of food a human typically eats in a year. Astronauts will also need variety, both for nutrition and for their mental health. Growing crops in space could solve some supply needs, but NASA experiments to date have only had astronauts growing a maximum of five percent of their food in space, said Platts. Crew members will also need to handle medical emergencies on their own. NASA is exploring the use of artificial intelligence to help astronauts solve medical problems, as well as providing compact ultrasound machines that can be used to diagnose issues, Platts said. Some technology will need to be invented, though — astronauts won’t be able lug around the large machines used on Earth to run medical tests. Gravity, or the lack thereof, is another major issue. Thanks to research from the International Space Station, NASA knows that astronauts have trouble regulating their blood pressure when exposed to microgravity for extended periods of time. It now issues astronauts with special suits that help them adjust to Earth’s gravity on their return. Other problems are still unsolved. Some astronauts experience vision problems in microgravity, a condition called Spaceflight Associated Neuro-Ocular Syndrome (SANS). NASA does not yet have a way to correct the problem. It also doesn’t know if the problem gets worse over time or if it plateaus — most astronauts stay on the ISS for six months, meaning that NASA only has high quality data for space stays of that much time. Platts said he’s confident that NASA will have solutions or at the very least a better understanding of the risks such that astronauts have “true informed consent” as to the risks they’re taking by NASA’s 2030s timeline. Speeding up the mission — as Musk appears to want — would mean astronauts won’t know exactly what they’re getting into, especially if NASA’s pursues Musk’s ambitious target of 2028. Musk may still be willing to send private astronauts on that journey. Trump, though, might not. While Trump relishes the idea of going to Mars, he also appears to be cognizant of the risk. In a 2019 National Space Council meeting with then NASA Administrator Jim Bridenstine, Trump repeatedly pressed the administrator as to why NASA couldn’t go to Mars. Bridenstine explained the problems — including that NASA needs to time its launches to moments when Mars and Earth are closest in their orbit around the sun. Trump dwelled on the consequences if astronauts missed that window, and replied twice: “You don’t want to be on that ship.”
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