// ORBITAL LOGISTICS AND PROPULSION TERM
Longitude of Periapsis
Longitude of Periapsis is one of the orbital elements that helps define the orientation of an orbit in space, specifically where the orbit's closest point to the central body is located.
TECHNICAL DEFINITION
Longitude of Periapsis is an orbital element that defines the orientation of the periapsis (point of closest approach) of an elliptical orbit within the orbital plane, measured from the ascending node to the periapsis in the direction of motion.
BACKGROUND
A low Earth orbit (LEO) is an orbit around Earth with a period of 128 minutes or less and an eccentricity less than 0.25. Most of the artificial objects in outer space are in LEO, peaking in number at an altitude around 800 km (500 mi), while the farthest in LEO, before medium Earth orbit (MEO), have an altitude of 2,000 kilometers, about one-third of the radius of Earth and near the beginning of the inner Van Allen radiation belt.
READ MORE ON WIKIPEDIASYNONYMS & ALIASES
- Longitude of Pericenter
- Longitude of Perigee
- Argument of Periapsis + Longitude of Ascending Node
USAGE NOTE
This element is crucial for precisely defining the orientation of an orbit in 3D space.
DEVELOPERS
Organizations developing technology related to Longitude of Periapsis.
Develops and manufactures advanced rockets and spacecraft. As a major launch service provider and satellite operator (Starlink), SpaceX extensively utilizes and develops technology for precise orbital insertion, maneuvering, and station-keeping, which critically depends on understanding and controlling orbital elements like the Longitude of Periapsis.
As a leading government agency for space exploration, scientific discovery, and aeronautical research, NASA's missions involve extensive work in astrodynamics, mission design, navigation, and spacecraft operations, where precise control and understanding of orbital elements, including Longitude of Periapsis, are fundamental for mission success.
Europe's gateway to space, involved in space science, exploration, Earth observation, telecommunications, and launch services. ESA's mission planning, satellite operations, and spacecraft design inherently require deep expertise in orbital mechanics and the precise management of orbital parameters.
A joint venture of Lockheed Martin and Boeing, providing reliable and cost-effective launch services for the U.S. government. ULA's launch operations are highly dependent on achieving precise orbital insertion parameters, making the Longitude of Periapsis a critical element in their trajectory design and execution.
A global aerospace, defense, security, and advanced technologies company with a significant space division. Lockheed Martin designs, builds, and operates a wide array of spacecraft and space systems, where astrodynamics and the precise definition and control of orbital elements are central to their engineering and mission success.
A European company that provides launch services for satellites. As a commercial launch provider, Arianespace is responsible for delivering payloads to specific orbits with high precision, which requires rigorous calculation and execution related to all orbital elements, including Longitude of Periapsis.
A major global aerospace and defense technology company, involved in a wide range of space systems, including satellites, launch vehicles, and space exploration. Their development of advanced propulsion systems, guidance, navigation, and control technologies directly impacts the ability to achieve and maintain desired orbital parameters.
Provides end-to-end space services, including small satellite launch services and satellite manufacturing. Rocket Lab's ability to precisely deploy satellites into specific orbits makes the control and understanding of orbital elements, such as Longitude of Periapsis, fundamental to their technology and services.