Perigee

TECHNICAL DEFINITION

Perigee is the orbital point of minimum distance for an orbiting body (e.g., satellite, spacecraft) from its primary (e.g., Earth, Moon), often used for orbital adjustments and re-entry planning.

BACKGROUND

Outer space, or simply space, is the expanse that exists beyond Earth's atmosphere and between celestial bodies. It contains ultra-low levels of particle densities, constituting a near-perfect vacuum of predominantly hydrogen and helium plasma, permeated by electromagnetic radiation, cosmic rays, neutrinos, magnetic fields and dust. The baseline temperature of outer space, as set by the background radiation from the Big Bang, is 2.7 kelvins.

SYNONYMS & ALIASES

• Periapsis
• Closest point
• Lowest point
• Min altitude

USAGE NOTE

Spacecraft often perform engine burns near perigee to efficiently raise their apogee.

DEVELOPERS

Organizations developing technology related to Perigee.

• SpaceX

  Designs, manufactures, and launches advanced rockets and spacecraft, requiring precise orbital mechanics for mission success, including managing perigee for satellite deployment and re-entry trajectories.

• NASA (National Aeronautics and Space Administration)

  A U.S. government agency responsible for space exploration and research. Heavily involved in mission planning, orbital maneuvers, and spacecraft operations, where perigee is a critical parameter for trajectory design and orbit maintenance.

• ESA (European Space Agency)

  An intergovernmental organization dedicated to space exploration and development. Plans and executes numerous space missions, performing detailed orbital calculations and maneuvers involving perigee for satellites, probes, and human spaceflight.

• Blue Origin

  An American privately funded aerospace manufacturer and spaceflight services company. Developing rockets and spacecraft for suborbital and orbital flight, requiring advanced knowledge and control of orbital parameters like perigee for successful launches and missions.

• United Launch Alliance (ULA)

  A joint venture of Lockheed Martin Space and Boeing Defense, Space & Security, providing launch services for U.S. government missions. Their work involves precise orbital insertion and trajectory optimization, making perigee a key consideration for payload delivery.

• Rocket Lab

  An American-New Zealand private aerospace manufacturer and small satellite launch service provider. Specializes in dedicated and rideshare small satellite launches, where accurate orbital insertion (including perigee control) is crucial for customer payloads.

• Northrop Grumman

  A major aerospace and defense technology company involved in satellite manufacturing, launch vehicles, and mission operations. Their expertise includes orbital mechanics and mission planning that incorporates perigee for successful spacecraft deployment and management.

• Airbus Defence and Space

  A division of Airbus specializing in defense and space products and services. Develops and builds satellites and related ground infrastructure, requiring deep understanding of orbital dynamics, including perigee, for satellite design and operational life.