// PROPULSION SYSTEMS AND ENGINE TECHNOLOGY TERM
Laser Sail
A laser sail is a proposed method of spacecraft propulsion that uses a powerful, ground-based or space-based laser to push a large, reflective sail. The constant pressure from the laser beam accelerates the sail and its attached payload to extremely high speeds, potentially enabling interstellar travel.
TECHNICAL DEFINITION
A laser sail is a type of beamed-energy photonic propulsion system utilizing momentum transfer from photons emitted by a high-power laser array. The laser beam's radiation pressure impinges on a large, ultra-lightweight, reflective sail (lightsail) to accelerate a spacecraft, enabling potential relativistic velocities for applications like interstellar probes.
BACKGROUND
Solar sails are a method of spacecraft propulsion using radiation pressure exerted by sunlight on large surfaces. A number of spaceflight missions to test solar propulsion and navigation have been proposed since the 1980s. The two spacecraft to successfully use the technology for propulsion were IKAROS, launched in 2010, and LightSail-2, launched in 2019. A further demonstrator, Advanced Composite Solar Sail System (ACS3), was launched in 2024, and deployed successfully but is not being actively controlled due to a fault.
READ MORE ON WIKIPEDIASYNONYMS & ALIASES
- laser-pushed lightsail
- beamed-energy sail
- photonic sail
- directed-energy propulsion
- laser-driven lightsail
- photonic propulsion
USAGE NOTE
This term is primarily used in theoretical and advanced propulsion discussions, especially concerning unmanned interstellar missions like the Breakthrough Starshot project.
DEVELOPERS
Organizations developing technology related to Laser Sail.
A research and engineering project by the Breakthrough Initiatives to develop a proof-of-concept fleet of nanocraft, called StarChips, propelled by a ground-based laser array. It is the most prominent and well-funded initiative focused on laser sail technology for interstellar travel.
The U.S. space agency, through its NASA Innovative Advanced Concepts (NIAC) program, funds research into advanced propulsion systems, including studies on directed energy and laser-thermal propulsion. NASA has a long-term interest in beamed-energy propulsion for rapid interplanetary and interstellar missions.
Led by Professor Philip Lubin at the University of California, Santa Barbara, this research group is the scientific and technical lead for the Breakthrough Starshot program. They conduct fundamental research on directed energy propulsion, developing the core concepts for using large phased arrays of lasers to propel spacecraft.
A non-profit organization dedicated to research and education on interstellar travel. They conduct technical studies on various advanced propulsion concepts, with laser-propelled sails being a key technology investigated in projects like Project Dragonfly.
A U.S. federal research facility with world-leading expertise in high-power laser systems, such as the National Ignition Facility. LLNL's capabilities in laser technology are critical for developing the ground-based 'beamer' component required for a laser sail propulsion system.
A federally funded research and development center (FFRDC) that provides technical guidance and research for national security space programs. They analyze and assess the feasibility of advanced future technologies, including various forms of beamed energy propulsion.
A research center at Johns Hopkins University that conducts research and engineering for NASA, the DoD, and other agencies. APL investigates and develops technologies for future space missions, including advanced propulsion concepts for deep space exploration.