Note:
(a) Himars is manufactured by Lockheed Martin, whose web page for Himars does not explain the mechanism to achieve precision. Nor can I find that information in the Web.
(b) US also sends precision bomb shells to Ukraine. The one I can find is M982 Excalibur https://en.wikipedia.org/wiki/M982_Excalibur
("is a GPS- and inertial-guided munition capable of being used in close support situations within 75–150 meters (250–490 ft) of friendly troops or in situations where targets might be prohibitively close to civilians to attack with conventional unguided artillery fire. * * * resistance to GPS jamming")
However, I can not fathom how a bomb shell can be precise, under the impression that the gun and explosion decide (mechanic force, that is) where the bomb will go.
-----------------
SLOVYANKA, Ukraine—American-supplied high-tech rocket launchers have begun arriving on the front line in eastern Ukraine. Already they are shifting the balance of power in the fierce artillery duel being fought with Russian forces, Ukrainian officers say.
For more than a month, a Russian field headquarters not far from here was frustratingly beyond the range of Lt Valentyn Koval’s Soviet-era artillery battery, he said. That changed last week, when Lt. Koval’s unit got a High Mobility Artillery Rocket position, largely destroying it
Under cover of darkness, Lt Koval's unit drove the truck-mounted rocket launcher into the Russian position, punched in coordinates and pressed the launch button. Six 200-pound missiles slammed into the Russian position, largely destroying it, said Lt Koval, who commands 2 HIMARS batteries (launchers).
The Russian base was one of about 10 high-value positions Lt Koval says Ukraine has hit in the 2 weeks since taking charge of the systems, the most sophisticated weaponry Washington has supplied to Ukraine since the Russia invaded Feb 24.
Ukrainian soldiers operating HIMARS say they have doubled their reach into Russian-held territory with greater precision and less risk to themselves. Kyiv officials say such weaponry is their best hope to defeat the Russians.
"These Himars [sic] are very powerful. They allow us as much as possible to put a stick in their wheel," 22-year-old Lt Koval said about the Russian forces. "Russia has nothing comparable."
Four Himars batteries were delivered in June and four more are expected by mid-July. On Thursday, President Biden said Ukraine would get more batteries from other countries and more ammunition from the US as part of a new $800 million assistance package.
Washington initially was reluctant to provide Himars, fearing such a move could cause Moscow to retaliate against the US or its allies in the North Atlantic Treaty Organization. The rockets have roughly twice the range of the M777 howitzers that the US has provided to Ukraine.
"They can hit Russian systems with them,: said Sam Cranny-Evans, a research analyst at the Royal United Services Institute think tank in London. A lot will depend on the quality of the Ukrainians' intelligence and reconnaissance of Russian targets, he added, but Moscow will be looking to destroy the Himars so they don't pose a threat.
Ukrainian officials have argued that they need longer-range artillery to offset the Russian military's enormous firepower. The US has declined to provide Ukraine with longer-range rockets that can be fired by the Himars at targets up to 185 miles away.
Russian officials have sharply criticized the USA decision to supply Himars, saying Washington is pouring fuel on the fire and threatening to respond if the systems are used to target Russian territory.
For the Ukrainian operators, Himars provide an opportunity to level the playing field against an enemy that has more men and more guns.
Each Himars fires six precision-guided rockets with a range of up to 48 miles, giving the Ukrainians the ability to strike Russian command posts, ammunition and fuel depots, as well as troop concentrations in rear areas.
Soviet-designed Smerch and Uragan long-range multiple-launch systems are imprecise and time-consuming in use, relying on analog instruments for targeting. The systems are unarmored, difficult to maneuver and often break down.
Himars are smaller and easier to maneuver, helping them hide from enemy reconnaissance. Crews work inside an armored cabin. And they are fast: once parked, they can begin launching rockets within two or three minutes and move gain 20 seconds afte firing.
"You press three buttons. A few seconds and the system is ready to shoot,: said Lt Koval. "I don't have enough fingers to count all the advantages of Himars."
Due to the $155,000 prude tag for each rocket, the Ukrainians are focusing on high-value targets such as military headquarters, weapone depots and barracks. They expect this will force Moscow to pull assets back from the front line, which will further stretch it strained logistics.
On his body armor, Lt Koval wears a patch he received from a US instructor showing a coiled rattlesnake above the words “Don't tread on me." He said he is grateful to the american people for providing sophisticated weaponry.