NeurAstra
S02 → Altanube Pando
S06 → Nimbus.Archives
S07 → N400
S08 → AofAP
Satellite Orbits for Connectivity and Communications:
What are the Benefits and the Limitations?
SPACE ESSENTIALS
Since the launch of the first space satellite, Sputnik I, in 1957 by the Soviet Union, orbits around Earth have never been so crowded.
Commonly classified according to their function and the place they occupy up there, artificial satellites cover a wide range of purposes. Among them, satellites designed and deployed for connectivity and communication are of particular importance. Because of their relay capacity—allowing them to receive signals from one location on Earth and retransmit them to another—and their ability to quickly cover vast geographical areas, they play a crucial role in enabling access to network services around the globe, particularly in underserved areas without, or limited, terrestrial infrastructure.
Depending on the mission’s objective and requirements, these satellites can be sent in different orbits around the Earth. They are commonly found in geostationary orbit (GEO)—at an altitude of approximately 35,786 kilometres above the Earth’s equator—when used for applications requiring constant coverage, such as television broadcasting, weather monitoring, and communication services. When launched in medium earth orbit (MEO)—at altitudes ranging from 1000 to 35,786 kilometres above the Earth’s surface—they are used for navigation systems like the Global Positioning System (GPS) in order to provide precise positioning and navigation data. Ultimately, those situated in low Earth orbit (LEO)—from a few hundred to around 1000 kilometres above the Earth’s surface—are essential for applications requiring closer proximity to Earth, such as satellite internet constellations, Earth observation, and scientific research missions.
As a single satellite has a limited coverage area determined by its orbit and antenna characteristics, it is common to deploy satellite constellations. From LEO and MEO, these groups of satellites are thought to work together as a system, allowing global coverage and constant connectivity to a region.
However, several limitations can temper their applications. Satellites situated in a higher orbit, such as GEO, can display signal latency due to the time needed for signals to travel to and from the satellite, which has direct consequences in real-time communication. Adverse weather conditions can further worsen this concern. Satellites also have finite capacity constraints, leading to clutters and reduced performance in densely populated areas or during peak usage periods. Eventually, despite satellite orbits providing global coverage, there may be gaps in obstructed areas due to dense vegetation, atmospheric conditions, or space debris saturation. This can result in service interruptions or in degraded connectivity.
Beyond the issues regarding their functioning, it is worth noting that building, launching, and maintaining satellites is a costly enterprise, requiring substantial investments and limiting so resource-constrained regions’ access to these applications. Ultimately, the proliferation of satellites in orbit considerably augments the risk of collisions with space debris and increases the probability of interference with other satellite systems. As their presence poses a real threat to satellites as well as other space operations, orbital debris are currently at the core of several discussions involving space exploration leaders in order to commit to certain behavioural norms and set an example for the entire space community.
—
Further Readings:
—
© NeurAstra 2024
This article was first shared for the ESA blogs.