The following is from the September 15, 2021, Congressional Research Service report “Navy Lasers, Railgun, and Gun-Launched Guided Projectile: Background and Issues for Congress”:
This report provides background information and issues for Congress on three potential new ship-based self-defense weapons for the Navy—solid-state lasers (SSLs), the electromagnetic railgun (EMRG), and the gun-launched guided projectile (GLGP), also known as the hypervelocity projectile (HVP).
The Navy’s proposed FY2022 budget requests research and development funding for continued work on SSLs, but proposes suspending further work on the EMRG and GLGP programs and requests no research and development funding for them.