HIMARS IN ACTION: Soldiers from the U.S. Army’s 1st Infantry Division fire missiles from the M142 High Mobility Artillery Rocket System. Their unit is participating in a Decisive Action Rotation at the National Training Center, Fort Irwin, Calif. Photo taken Sept. 14, 2020. Here’s a photo from 2017 that shows the launcher firing a rocket from a beach in South Korea. For background on the HIMARS, see this Artillery update from 2017. The HIMARS is a very useful weapon system. It can fire precision-guided rockets and the 12 ton truck-launcher can fit into a C-130 transport plane. Here’s a photo of a U.S. Marine HIMARS landing on a beach. The Army and Marines have both experimented with using advanced sensors to spot targets for the long range, precision-guided rockets HIMARS and its the larger MLRS (Multiple Launch Rocket System) can fire. An Air Weapons update from 2018 reported the Marines discovered the F-35B is a very good forward observer for the HIMARS. The Marines fired HIMARS from the flight deck of an amphibious assault ship — a clever way to give the assault ship the ability to provide gunfire support for Marines ashore. The 2018 article includes some of the data in the 2017 update.
UPDATE: When the Marines use the F-35B as a forward observer the plane remains in stealth-mode, as best it can. The plane detects targets and relays target information — to the ship though I understand it could be sent directly to the HIMARS launcher. In some ways it’s comparable to a hidden spotter providing information to a sniper. The rockets are accurate out to 70 kilometers and there are longer range versions. In stealth mode the F-35B does not carry external weapons. The plane could be detected if the data transmission were intercepted, but given the plane’s capabilities, it’s difficult for an enemy to quickly turn that into targeting data (ie, target the F-35B). In comparison, if the jet were conducting the attack or even carrying external weapons it would almost certainly reveal its presence and position.