Multimillionaire space tourist Dennis Tito, one of seven civilians to ever go to space, announced that he would try to undertake a mission to the Red Planet in 2018 using SpaceX’s Dragon capsule. The “Inspiration Mars Foundation” wants to put two people in a small capsule for a 501-day Martian flyby. This is a little easier said than done.
To understand why this is such an ambitious undertaking, it’s important to know how spacecraft move. Einstein’s general theory of relativity explains that gravity due to the curvature of space-time causes the orbital motion of the planets. Basically it says that the planets move in ellipses or slightly eccentric circles. This type of movement is pretty efficient, so we emulate it with the movement of our spacecraft.
To move between planetary bodies, we use what are called transfer orbits. After exiting the Earth’s atmosphere, a rocket will execute a burn that will put it on a trajectory that looks pretty similar to a planetary orbit. In terms of fuel, these transfer orbits lead to the most efficient ways of moving between planets. But the downside is that they are very slow.
So our first difficulty lies in the fact that the proposed mission will take close to 17 months to complete and require two people to occupy 350 cubic feet of pressurized living room, carrying all of their food, water, and air with them. The food requirement alone is 3,000 pounds. The spacecraft is just too small.
Wallace Fowler, aerospace engineering professor and director of the Texas Space Grant Consortium, says: “A Dragon capsule would be suitable for several days — maybe a week or two, but not a Mars trip lasting months.” And even if those factors are dealt with, more problems of living in space —radiation poisoning, psychological degradation, muscle atrophy and calcium loss in bones —would be even harder to solve.
Because cosmic rays constantly bombard our Solar System, radiation poses a serious threat to any manned mission to Mars. On Earth, our atmosphere and magnetic field protect us from that radiation, but spacecraft are unprotected. Without proper shielding the crew will suffer serious radiation poisoning. Fowler thinks that because this radiation problem has yet to be solved, the whole mission “could be a disaster.”
Astronaut training includes a regimen of isolation and confinement, but not on the scale of what this mission proposes. The mission poses serious psychological problems for astronauts. Sensory deprivation, the lack of a proper sleep and wake cycle and social deprivation present issues for those spending lengthy amounts of time in space. Retired Russian cosmonaut Valeri Polyakov holds the record for the longest single spaceflight at 14 months, and this was aboard a larger Mir space station with two other cosmonauts. Although he suffered no long term mental effects, he had severe mood problems after returning to Earth.
And if Polyakov’s mental health wasn’t a problem, his muscles and bones definitely were. Because humans evolved on Earth, our bodies were molded by its gravity of 9.81 meters per second per second. When introduced to a weightless environment, however, muscles atrophy and waste away. NASA’s Johnson Space Center has conducted studies that show that astronauts can lose 20 percent of their muscle mass on spaceflights that last five to 11 days. ISS astronauts combat this by working out for two and a half hours a day on specialized equipment in an ISS module much larger than the entire Dragon capsule. But even with this sophisticated exercise equipment, no proven methods to reverse the effects of bone loss during spaceflight. Studies have shown that bone mineral density can decrease by up to 5 percent a month, and takes much longer to regain after returning to Earth.
I welcome the hype about a Mars mission, but suggest caution. We should have teams in space, out of low-Earth orbit, on the moon even. Dennis Tito and the Inspiration Mars Foundation should be working to fund the correct research and a vehicle that is purpose built, because their current plan is not feasible. We should go to Mars, but we need to go about it the right way.
Simmons is an aerospace engineering senior from Austin.