Brian Greene’s annual World Science Festival hit Manhattan again last week, and AiPT! Science was there! Keep coming back all week for more coverage!
Ever since the publication of H.G. Wells’ novel, The War of the Worlds, Mars and Martians have been staples of science fiction. We’ve seen friendly Martians in DC Comics’ J’Onn J’Onzz and Futurama’s Amy Wong, and we’ve seen hostile Martians like Looney Tunes’ Marvin and the invaders in Tim Burton’s film adaptation of the classic trading cards, Mars Attacks!
But then there are the travelers to the Red Planet, like the titular hero of Edgar Rice Burroughs’ John Carter of Mars series, Dr. Manhattan in Alan Moore’s Watchmen, and astronaut Mark Watney in the novel and movie The Martian. This past Wednesday, the World Science Festival in New York City assembled a panel of experts to discuss how we actually get to Mars in reality, at an event titled We Will Be Martians.
The first hurdle is the launch. “Most of the power is making the escape velocity to get out of the atmosphere,” astronaut Yvonne Cagle explained. NASA Engineer Michelle Rucker said we typically use chemical propulsion to take off from the Earth, but that it’s not ideal for larger scale manned missions to Mars because it would require bringing much more equipment and supplies.
It’s easier to send a rover instead of people — a rover doesn’t require life support systems like food and bathroom facilities. Rucker estimated a crew of four would add about 20 times as much mass for this reason alone.
One launch option is using a “space elevator,” a cable or tether that provides a direct route for vehicles to travel from the Earth’s surface into space. “My understanding is, conceptually, it would work,” Rucker said. “There are some limitations in the materials right now. There’s a lot of research and development being done.” She feels the advancements made to produce a space elevator could be applied to traditional chemical propulsion systems, as well.
“It’s not necessarily one or the other. The technologies might support either/or, or something nobody’s even thought of yet,” Rucker said. But she raised another concern. “Once the tether is damaged, what’s your backup plan?”
Another alternative for a more efficient launch is a Lunar Orbital Platform-Gateway, something that NASA’s been planning for five years. The idea, according to planetary geologist Ellen Stofan, is to bypass the problem of meeting Earth’s escape velocity by launching a Mars mission from a smaller scale space station near the Moon, which would come with an additional benefit.
“It’s also a great platform to use to then send down to the lunar surface,” Stofan said. “You’re going to want a multi-modular craft, because you’re always going to want to have somewhere to retreat to if something goes wrong.”
Of course, there’s also the issue of cost. “There are all these private companies that are helping to reduce the cost,” Stofan said. She and Cagle believe this project will receive international support as well as public/private collaborations.
Rucker discussed how timing, too, plays a critical factor in the mission.
So the analogy we like to use is, if you’re passing a ball to someone and someone’s running, you don’t aim it where they’re at now. We aim it where they’re going to be when you think the ball will arrive. And how hard you throw the ball is equal to how hard we have to throw our spaceships.
You can throw it harder, but it takes more energy, and that translates into more equipment. It could be more money. So you want to be able to do the easiest throw that you can do. And that happens about every 26 months.
But the launch is only the beginning. What about the actual voyage? Stofan believes the smaller the ship, the better. Rucker says we’re currently looking at solar/electric propulsion, however, chemical or nuclear propulsion could work as well, or some hybrid of all these options.
“One of the big things is whether or not to try to simulate gravity,” said space scientist Kim Binsted. One way to achieve this would be something similar to the wheel design seen in the film 2001: A Space Odyssey, but there are other methods as well. Most of the designs, however, don’t attempt artificial gravity.
Putting the crew in suspended animation, similar to what we’ve seen in movies like Alien and Passengers, is also being considered, according to Cagle. In this human hibernation, our metabolic functions are slowed down to preserve power, like putting your iPhone on low battery mode. The crew is then woken up when robots sent in advance have completed construction on a habitat.
“To get to Mars and back again is about 2,000 times as far as going from here to the Moon,” Rucker said. “When we put landers or probes or vehicles, it’s been about, you know, not quite a year, somewhere between six to eight months. But for humans, since we have to take a longer route, we’re looking at nine months, traditionally. If we do something that’s more of a vehicle energy boost, we can get it down to six months.”
“If you have to bring all of the water to get your crew there, to keep them alive on Mars, and to bring them back home again, that’s a lot of water,” Binsted said. “And that will severely affect the mission’s parameters. But, if you could send ahead an automated system that can extract some of the water that’s already on Mars and make it usable for humans, then that cuts out roughly two thirds of what you need. And that makes a huge difference. It makes the mission much more feasible.”
The Mars 2020 Rover will actually take the first step of these robotic precursor missions to prepare for human arrival by pulling carbon dioxide out of the Martian atmosphere. But once we do start sending people to Mars, Stofan believes landing is the hard part. If you thought you’ve experienced turbulence on a commercial flight, a Mars landing is so rough that Jet Propulsion Laboratory produced a video about it ominously titled “7 Minutes of Terror”:
And the danger doesn’t end there. While space comes with increased radiation exposure, according to Cagle, the thin atmosphere of Mars means we’d definitely have to protect ourselves there, too, influencing whether we place our habitat on the surface or below. Water shields from radiation, so Stofan suggested lining crew sleeping areas with water barriers to mitigate overall exposure on the surface.
Extreme temperatures are another concern. And due to the pressure, we’d have to remain in a pressurized space suit when outside to keep our blood from boiling. The crew sharing each other’s germs in close quarters is another problem. Mental health is another concern. Binsted conducts research on human space exploration by isolating six people at a time in a habitat for periods of 4-12 months, to learn how people cope with the stresses of such close quarters isolation.
It’s taught us what personality types are best suited for the trip. Strong conflict resolution skills are needed, as is access to exercise, music or other art, maintaining some form of connection to family and friends, and being able to keep up with news from Earth. Communication between Earth and Mars could be established with about 45 minute delays, combating the isolation of being alone on Mars.
There’s good news, though. It doesn’t rain or snow on Mars, and wind and dust storms aren’t as extreme as those seen in The Martian, because of the low density of the atmosphere. Conditions also allow for cooking and growing food on Mars, and 3D printers could also produce food. Experts are exploring the idea of terraforming Mars, a process to try to make the planet more Earth-like, by causing the atmosphere to be denser and more oxygen-rich, so people could live without a pressure suit and pressurized habitat.
We’re also considering what a community with children on Mars might look like. The panel confirmed producing the kids shouldn’t be a problem. “Physiologically, the reproductive system seems to be somewhat protected from the presence or absence of gravity,” Cagle said matter-of-factly. “We’re very much interested in demonstrating proof of concept.”
Given the enormous risks, why even make the trip to Mars in the first place? Stofan’s interest is mostly scientific, while Cagle wants to go herself.
The only way to know is to go. And so exploration has always been a part of the human spirit — and the curiosity, the passion, the discovery that are our tools, our true vehicles to get us there. And the only way to know yourself is to go in search of yourself.
And so, until we really go and push the envelope, we don’t know the full capability, capacity of the human envelope. And, to me, that’s just something that has to be — not just know — but the journey to get there is really the reward, whether we find out the complete answer at the destination.
“I want to make Earth our home,” Binsted added. “You only start talking about your home when you leave it and you return to it. When you’re a kid, your town is just ‘town.’ You only talk about it as your hometown when you leave it and come back. And so I would like humanity to leave Earth, live somewhere else for a little while, and then come back to their home planet. And I hope that perspective would help us treat everybody how they want to be treated.”