A laser broom is a proposed ground-based

laser A laser is a device that emits light through a process of optical amplification based on the stimulated emission of electromagnetic radiation. The word "laser" is an acronym for "light amplification by stimulated emission of radiation". The fi ...

beam-powered propulsion Beam-powered propulsion, also known as directed energy propulsion, is a class of aircraft or spacecraft propulsion that uses energy beamed to the spacecraft from a remote power plant to provide energy. The beam is typically either a microwave or a ...

system whose purpose is to sweep space debris out of the path of other

artificial satellites A satellite or artificial satellite is an object intentionally placed into orbit in outer space. Except for passive satellites, most satellites have an electricity generation system for equipment on board, such as solar panels or radioisotope ...

such as the

International Space Station The International Space Station (ISS) is the largest modular space station currently in low Earth orbit. It is a multinational collaborative project involving five participating space agencies: NASA (United States), Roscosmos (Russia), JAXA ( ...

. It would heat one side of an object enough to change its orbit and make it hit the atmosphere sooner. Space researchers have proposed that a laser broom may help mitigate

Kessler syndrome The Kessler syndrome (also called the Kessler effect, collisional cascading, or ablation cascade), proposed by NASA scientist Donald J. Kessler in 1978, is a scenario in which the density of objects in low Earth orbit (LEO) due to space pollutio ...

, a theoretical runaway cascade of collision events between orbiting objects. Space-based laser broom systems using a laser mounted on a satellite or space station have also been proposed.

Mechanism

Lasers are designed to target debris between in diameter. Collisions with such debris are common of such high velocity that considerable damage and numerous secondary fragments are the results. The laser broom is intended to be used at high enough power to penetrate through the atmosphere with enough remaining power to

ablate Ablation ( la, ablatio – removal) is removal or destruction of something from an object by vaporization, chipping, erosive processes or by other means. Examples of ablative materials are described below, and include spacecraft material for ...

material from the target. The ablating material imparts a small

thrust Thrust is a reaction force described quantitatively by Newton's third law. When a system expels or accelerates mass in one direction, the accelerated mass will cause a force of equal magnitude but opposite direction to be applied to that sys ...

that lowers its orbital

perigee An apsis (; ) is the farthest or nearest point in the orbit of a planetary body about its primary body. For example, the apsides of the Earth are called the aphelion and perihelion. General description There are two apsides in any ell ...

into the upper atmosphere, thereby increasing drag so that its remaining orbital life is short.Ivan Bekey,
Project Orion: Orbital Debris Removal Using Ground-Based Sensors and Lasers
.", ''Second European Conference on Space Debris'', 1997, ESA-SP 393, p. 699. The laser would operate in pulsed mode to avoid self-shielding of the target by the ablated plasma. The power levels of lasers in this concept are well below the power levels in concepts for more rapidly effective anti-satellite weapons. Research into this area demonstrates the precise physics involved, which shows that space debris orientation is significantly relevant to resultant trajectory of the ablated object. Using a laser guide star and adaptive optics, a sufficiently large ground-based laser (1 megajoule pulsed HF laser) can deorbit dozens of objects per day at a reasonable cost.

History

The

Space Shuttle The Space Shuttle is a retired, partially reusable low Earth orbital spacecraft system operated from 1981 to 2011 by the U.S. National Aeronautics and Space Administration (NASA) as part of the Space Shuttle program. Its official program ...

routinely showed evidence of "tiny" impacts upon post-flight inspection. ''Orion'' was a proposed ground-based laser broom project in the 1990s, estimated to cost $500 million. A space-based laser also called "Project Orion" was planned to be installed on the

in 2003. In 2015, Japanese researchers proposed adding laser broom capabilities to the Extreme Universe Space Observatory telescope, to be launched to the ISS in 2017. In 2014, the European CLEANSPACE project published a report studying a global architecture of debris tracking and removal laser stations.

References

External links

BBC News report on Laser broom

ABC

Agence France-Presse story via SpaceDaily
Orbiting Junk Continues to Threaten International Space Station
Space.com
Shuttle to test space junk broom
New Scientist

by Claude Phipps
Wired October 2011: Space Junk Crisis: Time to Bring in the Lasers
story on Wired
Removing Orbital Debris with Pulsed Lasers
Broom, laser Spacecraft propulsion Space debris

Mechanism

History

References

Further reading

External links