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Telepresence

Telepresence refers to the use of cameras and other equipment to remotely study a distant environment. This technology is primarily used to explore places that are inhospitable to humans. Scientists have used robotic vehicles on Earth to explore active volcanoes and the ocean floors. But telepresence has been used primarily to explore other worlds. Some vehicles, such as the Lunar Surveyor missions that set down on the Moon's surface in the 1960s and the Viking stations that landed on Mars in 1976, remained stationary and analyzed materials within the reach of their experiments. Other vehicles were mobile rovers, such as the Soviet Lunakhod missions that explored the Moon in 1970 and 1973 and the Sojourner rover, which was part of the Mars Pathfinder mission in 1997.

Telepresence allows scientists to learn about a hostile environment without endangering human life. In some cases, such as the exploration of Venus's surface by the Soviet Venera missions, the environment is so inhospitable that human explorers might never be sent there. In other cases, landers and rovers are used to determine if the location is safe for humans. The Lunar Surveyor missions, for example, tested a theory that the Moon's surface is covered by a thick layer of dust that would swallow up anything that landed on it. The Surveyors revealed that the Moon's surface is solid, and the Apollo lunar landings with the American astronauts proceeded without problems.

When telepresence is used on Earth, the operator is typically in near-instantaneous contact with the robot so the robot's motions can be adjusted in real-time. However, when humans are on Earth and the robot in on another world, the limited speed of the radio signals (traveling at the speed of light) means that there is a time delay between when the operator sends a command and when the robot receives it. Thus, scientists typically develop a sequence of commands to send to the robot and allow it to act autonomously until the next contact period. Rovers usually have internal "fail-safe" modes so if they get themselves into trouble (for example, trying to climb a steep slope, such as the Sojourner rover tried to do several times), they will shut down until the next sequence of commands is received from Earth. Thus, telepresence is much more complicated than simply moving a joystick and seeing how the rover responds on another world.

Scientists look forward to the day when many activities will be completely conducted by telepresence. Some of the possibilities are already apparent. Teleoperated robots are used on Earth to clean up hazardous waste sites. Some Earth-based telescopes are conducting autonomous observations, alerting the operator only when they detect something unusual. The expected increase in technological capabilities will allow future robots to conduct mining operations on asteroids or construct habitats for human occupation on Mars before the astronauts even leave Earth. Increased opportunities for exploration and new ways to improve the lives of humans will be available through the enhanced capabilities of future teleoperated robots.

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