Is Mars the Future for NASA? (Discovery Departure, Part X) July 18, 2012Posted by Lofty Ambitions in Space Exploration.
Tags: Discovery Departure, Mars, Museums & Archives, Radioactivity, Space Shuttle
Earlier this year, we traveled to see the space shuttle Discovery transferred from Kennedy Space Center in Florida to the Udvar-Hazy Center near Dulles Airport outside of Washington, DC. (We wrote about that trip in posts HERE.) During the day of installation activities at the museum, we wandered over to a tent set up for visitors to learn about the Orion space capsule and ideas for more ambitious human space travel in the future. Mike Hawes, Director of Human Spaceflight at Lockheed Martin Space Systems and formerly Chief Engineer for the International Space Station, wants to figure out how to go to Mars.
Hawes explained that, going forward, NASA—or any other entity planning space exploration—will spacecraft that can be differently configured for different missions. A mission to Mars would require a configuration like nothing we currently have, and the specific configuration of launcher and crew vehicle will depend on the plan for how to get there. If we decide to set up an outpost on the Moon and launch a crew from there in the direction of Mars, that plan would require certain design assumptions. Those assumptions would be different if, instead of using the Moon as a stopping point, we decide an asteroid is an intermediate goal.
Hawes asserts, “We need to do some form of Gemini again.” We didn’t race immediately into Apollo and the Moon in the 1960s, and Hawes thinks we need a program to learn more about deeper space, in this context, a mission beyond low-Earth orbit, before we can manage the trip to Mars. What Hawes most wants to happen next is to set up outposts at a Langrangian point or two. These points out in space are the spots between two big objects—like the Earth and the Moon—where the gravitational pull on a third object like a space station (something much smaller than the International Space Station, perhaps two Orion capsules joined together) would be balanced and hold that object in place, relative to the two bodies. (This relationship is referred to as the three-body problem.) Hawes’s choice of Langrangian points for such an outpost would be L2 which is situated farther from the Sun than Earth and farther from the Earth than the Moon. There, the gravitational forces of the Sun and Earth would hold a space station in place while we figured out how to manage the long mission to Mars.
Hawes isn’t the only one to pose this idea. Neil deGrasse Tyson has mentioned it as an option. In his book Space Chronicles, he says, “Unlike a launch from a planet’s surface, where most of your fuel goes to life you off the ground, a Lagrangian launch would be a low-energy affair and would resemble a ship leaving dry dock, cast into the sea with a minimal investment of fuel. [...W]e can think of Lagrangian points as gateways to the rest of the solar system. From the Sun-Earth Lagrangian points, you are halfway to Mars—not in distance or time but in the all-important category of fuel consumption.” He goes on to imagine a future upon which we come to depend on what Hawes proposes: “In one version of our spacefaring future, imagine filling stations at every Lagrangian point in the solar system, where travelers refill their rocket gas tanks en route to visit friends and relatives living on other planets or moons.”
Hawes built on this idea, suggesting that an outpost could cycle between the L2 and L3 Langrangian points in the Earth-Moon system. As he talked, we started imagining how this sort of mission could be an end in itself, whether or not we want to go to Mars. Hawes points out that one of the most important things such a program would investigate is the psychology of deep space travel. For a crew hanging out at a Langrangian point, according to Hawes, there could be re-supply ships sent roughly every twenty-eight days, but there would be no “anytime return.” The crew would be stuck in a way no human space traveler has been stranded before.
We brought up a concern that STS-133 crew member and physician Michael Barratt has brought to our attention on a couple of different occasions. (See one of Barratt’s earlier conversations with us HERE.) Barratt studies the effects of radiation on the human body, and he says deep space poses huge obstacles because the radiation to which a crew would be exposed on a trip to Mars, using current propulsion systems and the speed they can achieve, would likely kill them. Hawes responded, “Internally, we have more shielding [in the vehicle], more shielding to do that [protect the crew from radiation], but Mike’s right.” Hawes sees the problem as something engineers can solve and adds, “We need to start testing materials to those radiation levels.” In other words, we have some basic problems to solve before we can send astronauts very far at all.
“The doctors always seem behind where the crew is ready to go,” Hawes said. That echoed a conversation we had with Jim Tully, the mayor of Titusville, Florida, who said he’d go on a one-way mission to Mars if he had the chance. People are excited about the idea of going to Mars, regardless of practical issues and regardless of the fact that we’ve already sent rovers there. And active research into how a human might survive the trip is underway, with the Mars Science Lander hauling along on its voyage to Mars a radiation detector so that we can measure and better understand the deep space radiation environment.
In fact, Curiosity will join Spirit and Opportunity on that planet’s surface in August. But Hawes thinks rovers have limits. A rover moves a few feet, stops, and reports back, with a lag time in communication. Rovers are useful but tedious, according to Hawes. “If it’s just robots,” he said, “they’re [the general public] not really invested in the vision.”
Everyone seems to agree that, if we’re going to send human beings anywhere beyond Earth’s orbit, we need a vision. Without a vision, we’ll miss the chance to solve a lot of problems, including radiation effects on people, and the chance to understand the universe in new ways. “We’re really just on the verge of needing these things,” Hawes told us. But he sees a bright future, in the near and long term, if we form a vision: NASA-based long-distance space programs are “going to engender commercial opportunities.” Just this month, NASA revealed more of its deep-space vision with the unveiling of the Orion Multi-Purpose Crew Vehicle.