NASA’s New Mission: Robots to Explore Alien Oceans
NASA is studying the possibility of sending robots to swim under the icy crusts of Europa and Enceladus.
NASA recently provided funding of US$600,000 for a study on the feasibility of sending swarms of miniature swimming robots in this way, being able to explore the oceans under the icy layers of the “sea worlds” of the Solar System.
Robots to navigate a̳l̳i̳e̳n̳ oceans
Pluto is a clear example of an ocean world. But the stars with the most accessible oceans are Europa, Jupiter\’s moon, and Enceladus, Saturn\’s moon.
Interest in a̳l̳i̳e̳n̳ oceans is not just in the amount of liquid water they contain, but because they may contain life. In fact, the environment in these oceans may be very similar to that on Earth, around the time life began.
In such environments, the water that seeps into the ocean floor rock is heated and chemically enriched. It is then expelled back into the ocean. Microbes can feed on this energy and, in turn, feed larger organisms.
These structures are known as “hydrothermal vents” and are studied at the bottom of the Earth\’s ocean. In these locations, the local food web is based on chemosynthesis rather than photosynthesis.
On most of these Solar System ocean worlds, the energy that heats the rocky interiors and prevents the oceans from freezing comes from the tides. This is in contrast to radioactive heating of the Earth\’s interior, but the interactions are similar.
The ocean of Enceladus has already been sampled by the Cassini spacecraft, through clouds of ice crystals rising from cracks. Additionally, there is hope that NASA\’s Europa Clipper mission can find similar plumes to sample when it begins a series of close flybys of Europa in 2030.
The problem is, going into the ocean to explore would be much more informative than simply sniffing a freeze-dried sample.
E̳x̳p̳l̳o̳r̳e̳ the ocean depths of other worlds
This is where the concept of independent micro swimmers, or Swim, comes in. The idea is for the robots to land on Europa or Enceladus, where the ice is thinnest, and use a radioactively heated probe to melt a 10-inch-wide hole.
Up to 4 dozen wedge-shaped swimming microrobots 12 centimeters long would then be launched. Its endurance would be less than that of the Boaty McBoatface, which crossed 100 meters under the ice of Antarctica.
Currently, Swim is just one of 5 Phase 2 studies in a series of advanced concepts from NASA\’s Advanced Innovative Concepts, or INIAC, program. So there\’s still a good chance that Swim won\’t become a reality.
The small robots would communicate acoustically with the probe via sound waves. The probe would send the data by cable to the lander on the surface. The studio will test the prototypes in a test tank with all subsystems integrated.
Each microswimmer could perhaps scan only tens of meters of the probe, limited by battery power. But their flocking action would map to changes in temperature and sanity. They can even measure changes in water turbidity. This could point the way to the nearest hydrothermal vent.
The downside is that power limitations can prevent them from carrying cameras or sensors that capture organic molecules.
A decade ago, the idea of sending a swarm of robots into space might sound like something out of a science fiction movie. However, everything seems to indicate that this is the path of space exploration.
