Have you ever seen a satellite high up in the sky among the countless stars on a hot summer night?

A satellite rotates around Earth at a consistent velocity so that it does not get affected by the gravitational pull of our planet. The velocity of a geosynchronous satellite is around 3km/s.

A satellite runs all 365 days a year, all 24 hours a day, so it requires a massive amount of (electric) energy to keep going. So where does this energy come from in this vast universe?

Well, thanks to solar panels, we can convert the infinite, pure energy of the sun into electricity. Solar panels are folded and attached to space launch panels, but they unfold when they reach the outer boundaries of the atmosphere.

Solar panels, the energy source of satellites

A satellite travels on a rocket to reach the outer boundaries of our planets and through the universe. The satellite loaded onto the paring receives electricity from the power supply (on Earth) before launching, and the energy source converts into the battery in the satellite a few minutes before launching.

The first thing a satellite does upon reaching outer space is to set its position (so that it can make contact with Earth) and unfolds its solar panel. This is because the satellite used its own battery starting from a few minutes before launching, so the system could be discharged.

 If the satellite is discharged, the satellite is unable to fulfill its given mission. Hence, the satellite must rapidly unfold its solar panel and receive sunlight to recharge the battery, in order to avoid the state of full-discharge.

How solar panels work

The paring of the space launch panel jolts violently, so the satellite's solar panel should be tightly fastened to the body of the satellite. The solar panel must first be carefully folded in the process, and fastening pins are used to attach it to the satellite body.

This is called HDRM, or the Hold Down Release Mechanism. Also, when the solar panel moves out, an explosive device is attached near the fastening pins, so that each pin can be cut off.

Sometimes, the fastening pins are not cut off because they are frozen (areas outer space where sunlight cannot reach are extremely cold). Thus, the satellite changes its position to help the fastenings located between each of the panels to receive sunlight.

Lastly, the motor starts to turn, and this power of the string being pulled moves the solar panel onward independently. A successfully separated solar panel can receive light from the sun and generate electricity that the satellite will use, and recharge the battery.

If these solar panels are developed and utilized to fit space solar power systems, we will be able to fully utilize the limitless energy from the sun (for free). This will not only bring beneficial impacts to space technology, but also to environment conservation.

The solar panel was developed as an eco-friendly way of generating energy, utilized in active houses (or energy zero houses). Implemented to the satellite-making technology, it will be far more useful if satellites will be able to directly send the energy back to Earth, making it easier for us to use the energy. This concept will be elaborated upon in the subsequent article. (Due to the lack of space for pictures)

picture source: navercast