Optics in low earth orbit satellites

Have you ever looked up in the sky and seen a string of glowing lights all in a line together? Is it an alien invasion? No, it's a network of low earth orbit (LEO) satellites that range from 211 to 382 miles (340 to 614 kilometers) above our planetary surface. These are much closer to Earth than geostationary satellites, which orbit at an altitude of about 22,236 miles (35,786 kilometers) and appear stationary relative to a fixed point on Earth's surface. The lower orbit results in significantly lower latency, or roundtrip time between the user and satellite, which is around 25 milliseconds compared to over 600 milliseconds for geostationary satellites.  Precision optical components play a crucial role in low Earth orbit (LEO) satellites, contributing to various functions and capabilities essential for the satellite's mission. Below are an explanation of some of the functions and roles of sensitive optical components in LEO satellites: 

Network and Communication  
Optical components such as precision mirrors and beamsplitters are employed in free-space optical communication systems on LEO satellites. Optical communication offers the potential for higher and faster data transfer rates compared to traditional radio-frequency communication. It can be particularly useful for inter-satellite communication and connecting satellites to ground stations. These types of satellites support activities like streaming, online gaming, and video calls in remote locations where standard Wi-Fi is not available. 

Earth Observation and Imaging 
High-resolution cameras and imaging sensors are used for Earth observation and imaging purposes. They capture detailed images of the Earth's surface, providing valuable data for applications like environmental monitoring, agriculture, disaster management, and urban planning. 

Remote Sensing 
Optical sensors on LEO satellites are sensitive to various wavelengths of light, allowing for remote sensing applications. They can capture data in visible, infrared, and other spectrums, enabling the monitoring of environmental changes, vegetation health, and natural resource exploration. 

Space Situational Awareness (SSA) 
We often think of satellites only observing our surface; however, objects traveling around Earth have become much more crowded. Sensitive optical instruments play a role in SSA by tracking and monitoring other objects in space. They can be used to detect and characterize space debris, track the movements of other satellites, and contribute to collision avoidance strategies. 

The integration of many optical components from mirrors to lenses, windows, prisms, and more in LEO satellites enhances their functionality, enabling a wide range of applications that contribute to scientific research, Earth observation, communication, and space exploration. The precision and sensitivity of these components are critical for achieving the mission objectives in the challenging environment of low Earth orbit.  

At Esco, we have nearly 70 years of experience in working with engineers and the aerospace community on everything from single-digit millimeter optics to large low-expansion windows. Let us know how we can assist you with your next project.