Why Space Stations Have Windows While Submarines Do Not

The presence of windows in space stations but not in submarines is a fascinating topic that reveals fundamental differences in the design principles and environmental factors of these vehicles. Understanding these differences can provide valuable insights into the distinct functions and limitations of space stations and submarines.

Pressure Environment and Design Principles

The primary reason for this distinction lies in the unique pressure environments these vehicles operate in. Space stations and submarines experience vastly different external pressures, which directly impacts their design and the inclusion of windows.

Space Stations

Pressure Environment: Space stations operate in a vacuum where the internal pressure is higher than the external vacuum. The external pressure is minimal, consisting of the slight pressure exerted by particles in the thin atmosphere of the Earth. The internal pressure inside a space station is maintained at 1 atmosphere, making it suitable for human habitation.

This environment allows for the presence of windows that meet specific design criteria. Windows in space stations are made from specially designed materials such as thick glass or transparent aluminum. These materials are chosen to withstand the unique conditions of space, including radiation and extreme temperature fluctuations. The presence of windows is crucial for astronaut well-being and mission success. They provide a clear view of the universe, supporting scientific observations, experiments, and general psychological health.

Functionality

The functionality of windows in space stations is multifaceted. Notable examples include the Cupola on the International Space Station (ISS), which provides a panoramic view of Earth and the surrounding space. This visual access is invaluable for conducting experiments, monitoring the external environment, and maintaining a sense of connection to the Earth. Moreover, windows play a vital role in ensuring the crew remains aware of their surroundings and can identify potential hazards or opportunities.

Materials and Engineering

The materials used for windows in space stations are engineered to be lightweight yet incredibly strong. This is essential because every kilogram of material is valuable when considering the launch cost of a spacecraft. Furthermore, these materials must be able to withstand the harsh conditions of space, including exposure to radiation and extreme temperature changes. The use of advanced materials ensures that windows remain intact and functional over the lifespan of the space station.

Submarines

In contrast, submarines operate in an underwater environment where the external pressure is significantly higher than the internal pressure. At just 200 metres below the surface, the pressure increases to 20 atmospheres, making it a challenging environment for windows to function as intended.

Pressure Environment

Pressure Environment: Submarines are designed to withstand the immense water pressure, which can be up to 2000 times greater than the atmospheric pressure at the surface. The external pressure on the submarine's hull needs to be counterbalanced with robust internal pressure to maintain the vessel's structural integrity. If windows were to be included, they would have to be incredibly thick and heavy, which would compromise the submarine's buoyancy and structural stability.

Structural Integrity

The inclusion of large, thick windows in a submarine would be impractical and risky. Instead, submarines use small reinforced viewports or periscopes to minimize the risk of failure. These viewports are strategically placed to allow for visual observation while ensuring the structural integrity of the vessel is maintained. The use of periscopes also helps to reduce the amount of water and debris that could potentially damage the large, heavy windows.

Functionality

Submarines often rely on advanced sensory systems such as sonar, radar, and other instruments for navigation and situational awareness. The murky underwater environment limits visibility, making large windows less practical. The use of sonar and other sensors provides more accurate and reliable information, especially in the low-visibility conditions of the ocean depths.

Conclusion

While space stations can afford to have windows due to their lower external pressure and the need for visual observation, submarines must prioritize structural integrity and pressure resistance. This leads to a lack of large windows in submarines, which are instead equipped with small reinforced viewports or periscopes. The design principles and environmental factors of these vehicles highlight the importance of adapting technology to specific operational needs.

The ISS, which typically does not face threats from depth charges and has a scientific mission, can make use of windows to provide a view of the external environment. In contrast, submarines, which must deliver weapons or conduct strategic operations, prioritize their structural integrity and functionality in harsh underwater conditions.

Understanding the differences between space stations and submarines in terms of their pressure environments and design requirements can provide valuable context for future technological advancements and missions.