As far as many people are concerned, there are just two ways of exploring other planets – either robots do it while all the humans stay back on Earth, or astronauts go and do so in person. Both approaches have their advantages and drawbacks. According to a trio of scientists, however, the best idea may lie somewhere between the two.
When remote-control rovers are used to explore other planets, there's a long delay between commands being sent from Earth and getting received by the robot – the same applies to data being sent from the rover to Earth. In the case of the Curiosity rover exploring Mars, the communications lag could be anywhere from five to 40 minutes, depending on how far apart the two planets are at the time.
"Even though signals commanding observations and measurements take only minutes or tens of minutes to reach Mars, a single research activity on Mars, from command to data return, can take a day or more," says Prof. Kip Hodges of Arizona State University's School of Earth and Space Exploration.
Given that astronauts on the surface of a planet can think for themselves, so they don't need to be remotely-controlled, latency isn't nearly as much of a limiting factor. The problem, however, is that they require a means of landing on and taking off from the planet, along with complex and expensive equipment that allows them to survive the harsh environmental conditions while they're down there. Even then, they're still being put at a great risk.
That's why Hodges partnered with Dan Lester at Exinetics and Robert Anderson of NASA's Jet Propulsion Laboratory to develop the concept of "exploration telepresence."
In a typical scenario, astronauts would travel to another planet, but they wouldn't go down to its surface. Instead they would park their ship in orbit around the planet, then send down telepresence robots. The astronauts would be remotely controlling the robots from the ship, seeing through their cameras and controlling their manipulator arms as if they were there themselves. Because of the short transmission distance involved, the communications lag would only be a fraction of a second.
When the mission was over, the robots would simply be left behind.
Ultimately, Hodges believes that putting humans directly on other planets is still the best way to go, but that his approach is a good stepping stone for the more immediate future. "There are important targets for scientific exploration for which we currently don't have the technology to land humans safely," he says. "Exploration telepresence could greatly expand the number of destinations where humans can do great science."
A paper on the research was recently published in the journal Science Robotics.
Source: Arizona State University