As we start looking towards more comprehensive exploration of the Moon and of Mars, the assumption is that we’re working on sending humans to the surface of those worlds. It’s going to be exponentially more difficult and dangerous than sending robots, but that’s what exploration is all about, right?
There’s an article in the current issue of Science Robotics that discusses an alternative approach—a kind of compromise between sending only humans or only robots. The idea is using robotic telepresence for planetary exploration. From orbit, the authors argue, a small team of humans would remote operate rovers and other robotic systems and as a result they could do more exploration while keeping the overall mission safer and cheaper.
We already use telerobotics for planetary exploration—we’ve got robots all over the solar system sending us data and then patiently doing what we tell them to do. This is different than telepresence, because of the latency involved: It takes long enough (minutes to hours) for a signal traveling at the speed of light to make it from Earth to Mars or Saturn and back again. That means that there’s no way for us to have a real “presence” experience.
In the Science Robotics article, Dan F. Lester, Kip V. Hodges, and Robert C. Anderson from Exinetics, in Austin, Texas, Arizona State University, in Tempe, and NASA Jet Propulsion Laboratory, in Pasadena, Calif., argue for sending humans into space specifically to reduce latency to something tolerable (better than 0.5 second), for example going into orbit around Mars (but not to the surface) just to make it so that humans can control robots on the surface through telepresence in near real-time—with the robots also doing things on their own when needed.
The European Space Agency (ESA) tried this kind of thing out recently, with an astronaut on the International Space Station (ISS) directly controlling a robot on Earth. We wrote about it here, and there’s an article from ESA here. NASA has been trying it in the other direction as well, controlling Robonaut 2 on the ISS from the ground.
There are lots of reasons why space agencies are working on orbital telepresence, many of which are illustrated in the NASA artwork at the top of this article. Using relatively simple assistive autonomy, a horde of robots can spend most of their time wandering around on their own, while a few humans jump between them via telepresence from orbit to provide guidance.
Due to the time-delay for signals to travel from Earth to Mars and back, NASA scientists can’t directly teleoperate a robotic explorer like the Curiosity Mars rover (shown above in a self-portrait combining multiple images taken last year). But astronaut-scientists aboard a spacecraft orbiting Mars may one day teleoperate in real-time a horde of exploration robots all over the Martian surface.Image: JPL/Caltech
The robot horde can consists of all kinds of different platforms, like driving robots, flying robots, robots that can scale cliffs, robots with arms, robots with drills, robots with lasers, or anything else you want. If some of the robots get stuck or break, it’s not a big deal, you’ve got more. Some robots could even collect samples on the surface, and then send them up to you inside little rockets. And, as autonomy improves and robots get better at autonomous navigation and even doing autonomous science, humans will be able to control more and more of them at once, only stepping in when necessary.
As I see it, there are two fundamental questions about using telepresence robots for exploration:
- The first is whether humans really can do a better job at exploration than robots can. It’s certainly true right now: Humans may not have the patience of robots, but we’re able to quickly and efficiently use all kinds of scientific tools, take samples, move things, traverse things, and use our brains and experience to very quickly make decisions about what’s worth exploring and what isn’t. Except for that last thing, you can easily imagine how a robot could easily make for better, or at least more efficient, explorers. A robot can move faster, lift and carry more, and handle a wider variety of terrain. As long as that robot has the same kind of sensing and manipulation capabilities as a human (or better, which isn’t hard to imagine), the only thing missing is the brains and experience. Putting a human in the loop through telepresence could solve that problem.
- The second question is much harder to answer: How much value is there in having a human experience another world in person? How do you calculate the worth of having humans walk on the Moon, for example? It was certainly an inspirational giant leap for mankind moment, but was it really worth the incredible hassle and expense of trying to keep those humans from dying there, and then having to bring them back again? Maybe in the 1970s, it was, because 1970s robots were mostly terrible. But again, imagine what robots will be like within the next five to 10 years, or more specifically, what telepresence will be like. My guess is that the audiovisual experience will be pretty close to the real thing, and that haptic controllers will make things feel nearly as real as, uh, reality. Even if that’s true, however, it doesn’t really answer the question—is it worth going somewhere in person, partly because it’s hard, just to be able to have that experience? And is it worth doing even if it’s so dangerous, and so expensive, that people die in the attempt and other exploration is sacrificed as a result?
As robots and telepresence get more capable and more reliable, NASA isn’t the only one who will have to make decisions like these. Already, you can rent telepresence robots for conferences and to tour museums (or zoos), getting some significant percentage of the value of being there in person without having to spend time and money on travel.
It’s certainly better than nothing right now, but at some point, it might be almost as good as the real thing in some ways, and even better than the real thing in others. For those of us who don’t have the option for travel, telepresence will be a valuable tool, and for those of us who do have the option for travel, we’ll have to decide whether it’s really worth it, for destinations around this world, or to another.
[ Science Robotics ]
Evan Ackerman is a senior editor at IEEE Spectrum. Since 2007, he has written over 6,000 articles on robotics and technology. He has a degree in Martian geology and is excellent at playing bagpipes.