Communications from Earth’s surface can take longer to reach the sea floor than the moon. So the Orpheus drone is completely autonomous — when it decides (on its own) to come up for air, it releases a couple of steel weights that fall to the sea floor, allowing the machine to float up to the surface. Ideally, the drone will do this when it has completed its mission or if it times out.
“Hopefully it runs and goes, does its mission, and then returns to the surface and tells you where it is to be retrieved,” Leichty said.
If something goes wrong, the weights on the vehicle are designed to rust off within about a day, which would force the orange explorer back to the surface.
In the hadal zone, where Orpheus will one day travel if all goes to plan, the pressure can reach 16,000 pounds per square inch (psi), which is more than a thousand times the pressure at sea level (14.7 psi).
That’s not a place NASA has tended to care much about in the past — “NASA doesn’t really do ocean exploration,” Leichty said — but the pressure at the bottom of Earth’s oceans happens to be remarkably similar to the pressure on Jupiter’s tantalizingly watery moon, Europa.
“The ocean of Europa — that is thought to be one of the most likely places for life to exist right now, not just maybe in the past some time,” Leichty said.
That makes the Jovian moon a ripe place to search for aliens.
But before a mission to Europa ever becomes possible, scientists must learn how to recognize and observe forms of life that might thrive at such pressures, so that researchers don’t wind up ignoring an unknown sign of life that’s right in front of their eyes. The ability to recognize living beings at the bottom of the ocean — the otherworldly animals that thrive inside long, narrow ocean trenches — is one of Shank’s biggest concerns.
“How did trench animals come to be?” Shank wonders. “Did life start in the trenches and then migrate out of the trenches? Or did it migrate into trenches and get caught there and stay there?”
A deep-ocean detective
Many of the spots on Earth that the Orpheus team wants the drone to explore are near the planet’s subduction zones, where areas of the sea floor get pushed below continental crust and lava flows. Submarine volcanoes are far more common than eruptions on land, and sizzling underwater vents sprout up in the areas where lava churns, creating an environment where life can thrive. Scientists didn’t realize these vents even existed until 1977.
Shank is convinced the team will find never-before-seen microbes in areas near these deep-ocean vents. That could lead to the development of new antibiotics and other drugs, as well as new ways of thinking about the necessary conditions for life.
Orpheus is designed to be a kind of ocean-floor detective in such areas; it’s being outfitted with sensors to detect methane, hydrogen sulfide, and helium, which are all promising ingredients for life.
“Animals like tube worms and clams and mussels and shrimp and snails love the hydrogen sulfide,” Shank said.
Unlike other underwater vehicles, Orpheus is designed to sit right on the sea floor and sniff these creatures out.
“Then it will pick up off of the sea floor and, like a grasshopper, land again somewhere else,” Shank said.
Eventually, the plan is for Orpheus to be joined by a fleet of other grill-sized drones. Shank referred to this as an “armada,” and said the troupe of about 20 drones would sniff around the deepest corners of world’s oceans for clouds of hydrogen sulfide, then zero in on them, land, and snap photos.
“These areas are going to be the next thing that will change the way we think about how life can exist on Earth — or any other planetary body,” he said.