The US Congress wants the Missile Defense Agency (MDA) to rapidly develop and demonstrate a boost-phase ICBM (and hypersonic weapon) intercept capability as soon as practicable.
Space-based laser weapons technology is one of the options.
The DARPA High Energy Liquid Laser Area Defense System (HELLADS) fourth phase is a ground-based laser weapon system demonstrator with an approximate average power of 150 kW. One of the goals is to make lasers lighter and more compact. The goal is 5 kg per kW. The High Energy Liquid Laser Area Defence System (HELLADS) will weigh just 750 kilograms and fit into a space about the size of a large refrigerator.
Dr. Michael Griffin undersecretary of defense for Research and Engineering indicates that the US will have 100-kilowatt-class weapons on Army vehicles, 300-kilowatt-class weapons on Air Force tankers and megawatt-class directed energy weapons in space for space defense within the next decade.
Megawatt lasers should be ready around 2023 and the SpaceX BFR would be able to deploy them in space
Congress is authorizing $50 million to push the missile defense laser effort. The effort will allow the continuation of research and development of the three separate laser-scaling efforts, with a goal of demonstrating a 500-kilowatt laser by 2021 and a “best-of-breed’ 1-megawatt laser capability by 2023.
Joseph Keelon, the Missile Defense Agency’s acting program executive for advanced technology wants compact megawatt-class lasers on drones, F-35s and other air force planes so that any vehicle that is in the right position can perform a boost-phase shoot down of an enemy missile.
A megawatt laser with HELLADS weight would be 5 tons. This would be too heavy to put into and F-35. A megawatt laser for a fighter jet would need to be 500 kilograms to 1000 kilograms.
The MDA has to produce a feasibility study on using UAVs and kinetic interceptors by the end of 2021.