Exploring the Divergent Pressures: Submarines vs. Spaceships
Ships designed for aquatic and extraterrestrial environments face unique challenges related to pressure. While submarines grapple with intense external pressure in water, spaceships must maintain stable internal environments in the near-vacuum of space. This article delves into the design considerations and challenges of each, elucidating why they are affected differently by pressure.
Submarines: External Pressure and Structural Design
Underwater Pressure: As submarines descend into the ocean, they encounter increasing water pressure. For every 10 meters of depth, the pressure increases by approximately 1 atmosphere (atm). At a depth of 1000 meters, the pressure can reach up to 100 atm, which can crush poorly designed structures. This is a critical challenge that submarine designers must overcome.
Structural Design: To withstand the immense external pressure, submarines are built with strong, thick hulls and materials that are highly resistant to deformation. They also rely on buoyancy to float and are meticulously designed to be watertight, ensuring that water does not enter the vessel. The durability and strength of the materials used are crucial to prevent the vessel from collapsing under the immense pressure.
Spaceships: Maintaining Internal Pressure in a Vacuum
Lack of Atmospheric Pressure: Spaceships operate in the near-vacuum of space, where there is very little atmospheric pressure compared to Earth's surface. Despite this vast difference in pressure, spaceships are designed to handle it effectively by maintaining a stable internal environment.
Internal Pressure: The cabin of a spacecraft is pressurized to create a safe and comfortable environment for astronauts. The materials used in the spacecraft's structure are engineered to withstand the internal pressure while ensuring that the vacuum outside does not cause damage. The design focuses on maintaining structural integrity without allowing the hull to rupture due to internal pressure.
Design Considerations and Challenges
The design challenges for submarines and spaceships are distinct. Submarines are built to resist high external pressures from water, while spaceships must maintain a stable internal pressure amidst the near-vacuum of space. This divergence in design considerations leads to different engineering solutions and materials being used in each type of vessel.
For any pressure vessel carrying people, the interior is pressurized to sea level, which is essentially 1 atmosphere. Airplanes and spacecraft have a slight pressure difference, but this is still maintained to ensure a stable and safe environment. Submarines, on the other hand, must handle the increasing pressure as they dive, with every 10 meters of depth adding an additional atmosphere of pressure. For a Virginia-class submarine, the test depth is publicly stated as about 250 meters, resulting in about 25 times the pressure on the outside of the vessel at this depth.
It is important to note that neither vessel is unaffected by pressure differences; they are simply designed to manage the pressure in their specific operational environments. The amount of pressure difference each vessel faces is the key factor in their unique design requirements.
Conclusion: The design of submarines and spaceships is a testament to the ingenuity of engineers in overcoming the challenges posed by their respective environments. While submarines must resist the crushing external pressures of the ocean depths, spaceships must maintain a stable internal environment in the vacuum of space. Both vessels are engineered with their operational environments in mind, leading to solutions that address the specific pressures they must overcome.
Key Takeaways: Submarines are built to resist external pressures in water. Spaceships maintain internal pressure in the vacuum of space. The design considerations for each vessel are distinct and tailored to their environment. The amount of pressure difference each vessel faces is a critical factor in their design.