How can solar systems be designed more effectively for space exploration?

1 Solar array configurations

The configuration of the solar arrays, which collect and convert sunlight into electricity, is a key factor that affects the design of solar systems in space. Depending on the mission objectives, the orbit, and the spacecraft size and shape, different configurations have different advantages and disadvantages. Fixed arrays, for instance, are attached to the spacecraft body and do not move. They are simple, lightweight, and reliable but have limited power output and may face shading or orientation issues. Deployable arrays, on the other hand, are folded during launch and deployed after reaching orbit. They can provide more power and adjust to the optimal angle of sunlight but are more complex, heavier, and prone to mechanical failures or damage from debris or micrometeoroids. Finally, concentrator arrays use lenses or mirrors to focus sunlight onto smaller cells. While they can achieve higher efficiency and reduce the area and mass of the arrays, they require precise pointing and tracking systems and may suffer from thermal stress or degradation.

2 Solar cell materials

When designing solar systems in space, the choice of solar cell materials is a crucial factor. Different materials offer varying properties, such as efficiency, cost, durability, and radiation tolerance. Silicon, for instance, is the most common and cheapest material for terrestrial solar cells. It has a moderate efficiency of 15-20%, but it is heavy, brittle, and sensitive to temperature and radiation changes. Alternatively, gallium arsenide (GaAs) is a high-performance material for space solar cells with an efficiency of 25-30%. It is lightweight, flexible, and resistant to radiation and temperature variations; however, it is also very expensive and requires complex manufacturing processes. Multi-junction (MJ) cells are composed of several layers of different materials that capture different wavelengths of light. They can achieve the highest efficiency of over 40%, yet they are also very costly and complex with lower reliability and higher degradation rates.

3 Emerging technologies

Besides the existing technologies, there are also some emerging technologies that promise to enhance the design of solar systems in space. Thin-film solar cells, for example, can reduce the weight, volume, and cost of the arrays; however, their lower efficiency and durability may require additional protection from radiation and debris. Organic solar cells, based on organic molecules or polymers, can offer low-cost and lightweight solutions; but they have very low efficiency and stability and may degrade quickly in the hostile environment of space. Solar sails are thin sheets of reflective material that can harness the radiation pressure of sunlight to propel a spacecraft without fuel; however, they are large and fragile, which could present issues with steering, control, and drag.

4 Here’s what else to consider

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