Inhale, inhale, inhale…inhale sunlight? Unveiling the secrets of the spacecraft's "energy wings"

Are you also curious about the big "wings" on the spacecraft? These "wings" are the main power and energy provider of the space station. Today, let's explore the secrets of these "wings" in depth!

The power wings of spacecraft: solar arrays

Solar panels on the Wentian experimental module

The "wings" of the spacecraft are covered with solar cells, scientifically known as "solar arrays". The working principle of solar arrays is similar to that of ordinary solar collectors, which can collect solar energy and convert it into electrical energy. However, energy conversion alone is not enough to support the stable operation of spacecraft in the harsh space environment. The key lies in how to obtain solar energy efficiently and continuously.

The biggest difference between the solar panels on a spacecraft and general solar collectors is that they can always face the sun like a sunflower. With precise solar orientation technology, the solar array can adjust its angle in real time to ensure that it is bathed in sunlight to the maximum extent, thereby absorbing enough sunlight and providing sufficient energy for the spacecraft. This part of electricity not only provides power for the real-time operation of the spacecraft, but also charges and stores energy for the battery. Once the spacecraft enters the shadow area of ​​the orbit that is out of reach of sunlight, the fuel cell that has been silently accumulating power before will be able to take over and supply stable and reliable electricity for the operation of the spacecraft, ensuring the orderly operation of various instruments and equipment. With the coordinated cooperation of solar panels and fuel cells, the energy supply problem caused by the alternating light in the space environment is cleverly resolved.

Solar Array Development Trajectory

So why don't spacecraft use batteries directly when performing missions, but instead use a solar panel + battery configuration? This is because solar energy can provide electricity continuously compared to batteries. Therefore, when performing space missions, spacecraft will choose the appropriate energy supply system based on the length of time. Long missions are more suitable for solar panels, and short missions are more suitable for batteries (including fuel cells). So when the mission time is long, such as a space station, solar energy is of course the best choice. But if the mission time is short, such as the Apollo spacecraft, there is no need to use solar energy.

Solar panel folding and unfolding mechanism

In addition, it is not difficult to find that under the limited launch weight constraints, solar cells are the most reasonable choice to ensure the long-term normal operation of high-power loads. The state of solar panels will change during different flight phases of the spacecraft. During the launch phase, in order to avoid the influence of oncoming aerodynamic flow, the panels are folded and stored in the fairing; after entering orbit, they are unfolded to provide power for the spacecraft.

Among many energy sources, solar energy is a relatively easy-to-obtain and sustainable energy source. In the space environment, solar energy is inexhaustible. As long as the solar panels can work properly, they can continuously convert solar energy into electrical energy.

And from the comprehensive consideration of the entire aerospace system, although there are problems such as risks in the deployment process of deployable solar panels, the risks can be reduced by equipping them with backup systems, setting multiple insurances and multiple fuses for explosive bolts, and improving their reliability, providing strong energy guarantees for the stable operation of satellites and other spacecraft.

Satellite in "spin" stabilization mode

At present, some spacecraft are in a "spin" stable mode with solar panels attached to the surface. Although the utilization rate of solar panels is low and there are maximum output power limits, they are relatively simple, less dangerous or even non-hazardous, and can meet the power needs of small satellites.

With the continuous development of spacecraft, the power consumption continues to rise, and the requirements for satellite mass utilization are also increasing. Moreover, with the increasing complexity and diversification of space exploration missions, higher requirements are also placed on the stability and reliability of energy supply for spacecraft. In the future, in order to provide more power for spacecraft, there may be new breakthroughs in the design of solar panels. For example, designing solar panels that can be rotated and unfolded, taking advantage of their ability to unfold into a flat surface, to provide more sufficient power for the spacecraft after the spacecraft enters orbit.

The dual engines of aerospace technology and industrial development

The technologies of aerospace solar panels in materials science, photoelectric conversion mechanism and system integration provide cross-border inspiration for terrestrial photovoltaic technology. For example, the research and development of new semiconductor materials, the application of multi-junction battery structure, and the experience of smart microgrid and energy storage management. These will help promote the transformation of the terrestrial photovoltaic industry towards high efficiency, flexibility and multifunctional integration. This will expand the market share of solar energy in areas such as building integration, transportation energy supply and off-grid energy systems, and promote innovation in application models.

With the continuous advancement of technology, solar panels are expected to achieve greater breakthroughs in improving the performance of spacecraft, such as higher photoelectric conversion efficiency, lighter weight, and stronger radiation resistance. Solar panels will continue to help the vigorous development of China's space industry and contribute more to the journey of human exploration of the universe.

Some information comes from: CNKI, Guangming.com, etc.

(Scientific reviewer: Liu Yong, researcher at the National Space Science Center of the Chinese Academy of Sciences)