by Robin Hegg
Humans have always dreamed of exploring the unknown, whether it was what lay beyond the horizon or what lay beyond the stars. While humans have achieved incredible feats in exploration—mapping the world and sending people to the moon—there is still unexplored terrain tugging on the human imagination, but potentially still out of our reach. Extreme environments—those with extreme temperatures, pressure, wind, or distance from earth—pose a challenge to the human body. Many of these environments are simply too dangerous for humans to explore on their own. Others are too far away for humans to explore in one lifetime. This is where robot explorers come into play. Robots are helping us to explore in space, under the water, and in the Antarctic.
NASA’s Mars rovers are exploring an extreme environment humans are not yet ready to explore themselves. Mars is one of the most interesting places to explore right now—it is the most Earth-like planet in our solar system and it has water, which means there is the possibility that life once existed or may still exist there.
Mars’ environment poses serious challenges, even to robot explorers. The temperature changes dramatically, dropping from as high as 20 degrees Celsius down to -120 degrees Celsius. The terrain is rough and rocky, we have no global positioning system (GPS), communications back to Earth are delayed, and huge dust storms can block visibility and clog up instruments.
The Curiosity rover, which landed in Gale Crater on Mars on August 6, 2012 is investigating the Martian environment, evaluating the field site inside Gale Crater to see if it may have offered favorable conditions for microbial life.
Curiosity has six 20-inch (50 cm) wheels in a rocker-bogie suspension. The wheels are designed for climbing in soft sand and scaling rocks. The rover’s wheels have cleats and move independently. Curiosity is able to climb over obstacles as high as 26 inches (65 cm). The rover is also able to self-monitor itself constantly to keep itself operational despite the extreme temperatures and dust storms. Curiosity has heating and cooling systems that work to keep the rover’s tools at optimal temperatures. It has two computers, one of which can take over if there are problems with the main computer. The rover’s communications also have lots of built-in redundancies, so that if one system fails, there are others that can take over.
Curiosity is equipped with 17 cameras that help it to avoid obstacles, navigate, search for points of interest, and examine and analyze Mars’ environment. With the help of an infrared laser, Curiosity can vaporize an interesting surface and then examine its composition. If it needs to examine the surface further, Curiosity can swing its robotic arm over and use its microscope and X-ray spectrometer to get a closer look. Curiosity can also collect a specimen using a drill, then move the sample into one of its laboratories. Curiosity also has a dust removal tool to help keep itself clean and functioning properly.
Curiosity is also investigating the habitability of Mars in preparation for possible future human exploration, including measuring radiation exposure inside the spacecraft during the trip to Mars. In the future, robots could act as aides for human explorers to other planets, scouting, recording, carrying gear, and serving as a rescuer if needed. Engineers plan to use Curiosity’s design as the basis for a Mars rover mission planned for 2020. You can keep track of Curiosity’s latest adventures by following Curiosity on Twitter.
The undersea world still holds mysteries we’ve yet to explore. Lack of oxygen and light, strong currents, and intense pressure can make exploring parts of the underwater world extremely challenging. Remotely operated vehicles (ROVs) stay attached to the ship by a long cable, which allows scientists to manipulate it. ROVs are able to reach great depths and can stay deep underwater for extended periods of time. Autonomous underwater vehicles (AUVs) are programmed explore the deep ocean and collect data. Scientists are able to conduct other research on board the ship while the AUVs explore on their own. Hybrid vehicles can operate attached or unattached. A hybrid vehicle called Nereus explored the Mariana Trench, the deepest part of the ocean.
A new robot from the Korea Institute of Ocean Science and Technology has been designed to explore areas with rough waters and strong currents that aren’t safe for divers and where propeller-driven ROVs and AUVs don’t work well and stir up debris. The robot, called CR200 or Crabster, was designed to resemble a giant crab with the hopes that it will be able to walk along the sea floor and endure strong underwater currents just like a real crustacean. Most crustaceans are aquatic animals. They have segmented bodies, a hard exoskeleton, legs, and antennae. While the robot is still in the testing phase, researchers hope to soon be able to send it to help archaeologists explore twelfth-century shipwrecks in the Yellow Sea, located between China and the Korean peninsula, that have been untouched for centuries.
Crabster’s bio-inspired design has six legs (unlike a crab’s eight) moving with 30 joints and a glass fibre shell designed to stand up to strong currents. It can also change its position depending on different pressure conditions. Its front legs may be given grippers, allowing it to pick up objects and store them inside a compartment. Crabster is connected to an external power source by a long tether, meaning it can stay underwater for days at a time. It has 11 cameras, including one sound based camera that can allow the robot to “see” in cloudy water. It will be able to make 3D maps of its surroundings using sonar.
In the future, Crabster may be able to help map the seafloor, survey and inspect shipwrecks and pipelines, respond to oil spills, and assist divers.
Another extreme environment robots are helping us to explore is the Antarctic. Robots like Yeti, a rover, explore the ice’s surface, helping to search for dangerous cracks, explore ice caves, and find things buried under the polar ice.
The robot ENDURANCE (Environmentally Non-Disturbing Under-Ice Robotic Antarctic Explorer) is mapping out the geochemistry and biology of the water in the Antarctic. ENDURANCE is an autonomous underwater vehicle (AUV) configured to the specific challenges of the Antarctic environment. ENDURANCE is designed to be deployed through a hole melted through a 3-meter thick ice cap, travel as far as 700 meters from the hole, and return safely through the hole following each mission. It seeks to examine the chemical makeup of the water, create a high-resolution 3D map of the underwater area, and, if possible, to form an image of the underwater glacier face.
ENDURANCE has four navigation systems, one of which helps the robot find the ice melt hole and return to the surface. ENDURANCE moves using thrusters and is able to hover within 5cm horizontally and 1cm vertically. It can also return to pre-defined locations.
ENDURANCE also includes 96 sensors to help it avoid obstacles, make maps, sense its speed and depth, and collect information. It has 16 different water chemistry sensors and four real-time cameras. ENDURANCE also has a science payload that sends a set of instruments into the water to examine the water’s chemistry and other interesting things below the robot where it may not be safe to travel. ENDURANCE is able to autonomously collect water samples while holding itself steady against the ice ceiling above it using “ice picks,” making sure not to disturb the area it’s testing.
NASA hopes that knowledge gained from testing ENDURANCE can help to explore objects in our solar system containing water, such as Jupiter’s moon, Europa.
Robots have already expanded the places we’re able to explore, allowing us to learn more about the world and universe around us. As robotic technology continues to move forward, humans and robots will continue to work together to learn and explore in new and exciting ways.