As the name implies, a low Earth orbit (LEO) is an orbit that is quite close to the surface of the Earth. It is often less than 1000 km above Earth, although it can be as low as 160 km, which is low relative to other orbits but still very high above the planet’s surface.
Even the lowest LEO is more than ten times higher than that because most commercial aircraft do not fly at altitudes much higher than 14 km.
LEO satellites’ planes are not necessarily required to follow a specific course around Earth, unlike GEO satellites, which must always orbit around the equator. As a result, there are more options for satellite paths in LEO, which is one of the reasons it is such a popular orbit.
LEO is useful for a number of reasons because to its close proximity to Earth. It is the orbit that satellites most frequently utilize for imaging since being close to the surface enables it to capture photos with a higher resolution. It is also the orbit in which the International Space Station (ISS) is located since astronauts can more easily and more quickly fly to and from it. The speed of satellites in this orbit is around 7.8 km/s; at this speed, a satellite completes one orbit of the Earth in about 90 minutes; as a result, the ISS completes 16 orbits of the Earth each day.
However, because they move so quickly across the sky and are difficult for ground stations to detect, individual LEO satellites are less valuable for operations like telephony.
Instead, in order to provide continual coverage, LEO communications satellites frequently operate as a huge combination or constellation of several spacecraft. These constellations, which include multiple of the same or similar satellites, are occasionally launched together to form a “net” encircling Earth in order to maximize coverage. This enables them to simultaneously cover a big portion of Earth by cooperating.
The Automated Transfer Vehicle (ATV), weighing 20 tonnes, was transported by Ariane 5 to the International Space Station in low Earth orbit.
In This Article...
What is the purpose of LEO orbit?
Between 2,000 and 200 kilometers above the surface of the planet, LEO satellites orbit. LEO satellites are frequently used for imaging, spying, military reconnaissance, and other types of communications.
What is a typical LEO orbit?
Unlike GEOs, LEO systems orbit the earth at altitudes between 700 and 3000 km while also moving relative to the planet. A typical LEO satellite completes an orbit around the planet in less than two hours, hence it is only visible for a brief period of time.
A polar orbit, is LEO?
During their orbit, certain LEO satellites travel over (or almost pass over) both of the Earth’s poles. A polar orbit is the name for this low-altitude, strongly inclined orientation.
LEO technology: What is it?
Modern hardware, software, and subject matter expertise are offered by LEO Technologies, LLC to Law Enforcement Organizations (“LEO”) at the Federal, State, and Local levels, as well as to prisons, the intelligence community, and the commercial sector.
How is a LEO satellite tracked?
X/Y antennas must move at a usual speed of three degrees per second to follow LEO satellites, and even faster to track a new satellite once the current spacecraft has left the field of view of the ground station.
Describe LEO and GEO.
Government and business leaders have argued about the superiority of geosynchronous equatorial orbit (GEO) satellites over low-earth orbit (LEO) satellites for providing communications for many years. As technology develops, a wide range of other issues, including cost, coverage, and maintenance, are constantly being considered. You can learn more about the various constellation structures and how they operate by reading this blog.
Let’s start with geostationary satellites, also referred to as geosynchronous equatorial orbits. These satellites are known as geostationary because they cover a certain area while orbiting at the same angular velocity as the Earth and on a route that is parallel to its rotation. GEO satellites appear to be immobile when viewed from the ground. This orbit, which is about 35,000 kilometers (22,000 miles) above the surface of the Earth, was originally utilized in 1964 for NASA’s Syncom III, an experimental communications satellite launched on a Delta-D rocket. Unfortunately, a geostationary satellite cannot provide continuous coverage above or below roughly +/- 70 degrees latitude because of the curvature of the Earth.
LEO satellites, meanwhile, orbit at an altitude of 160 to 2,000 kilometers (99 to 1,200 miles). As the satellite moves, a constellation of LEO satellites can offer constant, worldwide coverage. LEO spacecraft travel significantly more quickly than GEO satellites due to their proximity to Earth. For instance, a GEO satellite normally travels at 7,000 mph, whereas an Iridium satellite travels at almost 17,000 mph (completing an orbit every 100 minutes!).
LEO and GTO are what?
A geocentric orbit is a geosynchronous transfer orbit, often known as a geostationary transfer orbit (GTO). As a first stage in achieving their final orbit, geosynchronous or geostationary orbit (GSO)-destined satellites are (nearly) always placed into a GTO.
Highly elliptic is a GTO. Its apogee (furthest point from Earth) is often as high as a geostationary orbit, while its perigee (closest point to Earth) is typically as high as a low Earth orbit (LEO). As a result, it is an orbital Hohmann transfer between LEO and GSO.
A satellite bound for a GSO is typically launched into a GTO using the high-thrust engines of the launch vehicle, and then it transitions from the GTO into the GSO using its own (often extremely effective, low-thrust) engines.
The quantity of payload that launch vehicle manufacturers can fit into GTO is frequently advertised.
