ASAT

Asat, often written ASAT, is a term used primarily to refer to anti-satellite weapons—systems designed to damage, disable, or destroy satellites in orbit. ASAT capabilities may be exercised through kinetic-energy interceptors, which collide with a target; co-orbital or proximity approaches that disable a satellite; or non-kinetic methods such as directed-energy devices or jammers that degrade satellite operations without physical destruction.

History and examples: Several nations have pursued ASAT programs and conducted tests. Notable demonstrations include China’s 2007 kinetic-energy interception of the Fengyun-1C satellite, which produced significant orbital debris. In 2019 India conducted Mission Shakti, a kinetic kill vehicle test aimed at a satellite in low Earth orbit. Other countries have conducted earlier research or non-destructive evaluations. The deployment of ASAT systems raises concerns about space debris, long-term orbital safety, and the potential for escalatory arms competition.

Legal and strategic context: There is no comprehensive international treaty banning conventional ASAT weapons. The Outer Space Treaty of 1967 prohibits weapons of mass destruction in orbit and forbids placing them on celestial bodies, and it prohibits the threat or use of force against space objects; however, it does not outright ban conventional ASAT weapons. Debates about a PAROS regime have occurred. Debris from ASAT tests can pose risks to satellites and crewed spacecraft and complicate space operations.

Other uses: In medicine, ASAT has been used as an acronym for aspartate aminotransferase, an enzyme involved in amino acid metabolism and liver function tests; the more common abbreviation is AST.