// ORBITAL LOGISTICS AND PROPULSION TERM
Propellant Depot
A facility in space that stores fuel for spacecraft, allowing them to refuel for longer missions or to travel further.
TECHNICAL DEFINITION
A Propellant Depot is an orbital infrastructure designed to store and transfer propellants (e.g., cryogenic fuels, storable propellants) to other spacecraft, enabling in-space refueling, extended mission durations, and deep-space exploration.
BACKGROUND
An orbital propellant depot is a cache of propellant that is placed in orbit around Earth or another body to allow spacecraft or the transfer stage of the spacecraft to be fueled in space. It is one of the types of space resource depots that have been proposed for enabling infrastructure-based space exploration. Many depot concepts exist depending on the type of fuel to be supplied, location, or type of depot which may also include a propellant tanker that delivers a single load to a spacecraft at a specified orbital location and then departs. In-space fuel depots are not necessarily located near or at a space station.
READ MORE ON WIKIPEDIASYNONYMS & ALIASES
- Fuel station (space)
- Orbital refueling station
- In-space refueling
USAGE NOTE
Propellant depots are crucial for enabling sustainable deep-space missions and lunar/Mars exploration.
DEVELOPERS
Organizations developing technology related to Propellant Depot.
Orbit Fab is building the 'Gas Stations in Space' infrastructure, providing in-orbit refueling services for satellites and other spacecraft, which directly relies on propellant depot concepts.
SpaceX's Starship system is designed for in-orbit refueling to enable its long-duration missions to Mars and beyond, effectively using a Starship in orbit as a propellant depot.
Through its subsidiary SpaceLogistics LLC, Northrop Grumman is a leader in in-orbit satellite servicing, with plans to expand into refueling capabilities that would necessitate propellant storage and transfer systems.
ULA has been a long-time advocate and developer of concepts for in-space propellant depots and refueling, particularly through its Cislunar 1000 vision and proposals for ACES (Advanced Cryogenic Evolved Stage).
Lockheed Martin has extensively researched and proposed concepts for space logistics, including in-space refueling and propellant depots, as part of their broader vision for future space exploration and infrastructure.
Blue Origin's long-term vision for sustainable human presence in space, particularly their lunar ambitions, implies a significant need for in-space infrastructure, including propellant depots for refueling spacecraft.
Momentus is developing in-space infrastructure and orbital transfer vehicles (OTVs) designed to move satellites, which would greatly benefit from and potentially integrate with future in-space propellant depots for extended mission capabilities.