You, your crew and your craft float in hostile environs miles away from civilization. As you set about your mission, only a few inches of metal separate you from an environment that could kill you in moments. Your life depends on the engineers who designed your vessel. All it takes is one crack or puncture to rupture your shell and extinguish your life. These conditions apply equally to a submersible in the deep sea and a spacecraft beyond Earth. Given the similar risk of sudden death, it’s natural to ask: Which is safer?
Recent news shows the question is more relevant than ever. In June 2023 a submersible craft called the Titan operated byOceanGate Expeditions was crushed while descending to the wreck of the Titanic on the seafloor of the Atlantic Ocean, killing all five men inside. The incident occurred only two months after SpaceX’s Starship, the largest rocket built to date, exploded less than four minutes after surging toward space in its first test flight—luckily, no one was onboard.
Whether you’re going 20,000 leagues under the sea or from the Earth to the moon, spacecraft and submersibles follow many of the same engineering principles. Their passenger compartments are pressure vessels: containers designed, like an overachiever raised by demanding parents, to withstand high pressures inside and out.
