![The first Himars systems arrived in Ukraine in June 2022 and had an immediate impact on the battlefield](/https/www.telegraph.co.uk/content/dam/world-news/2023/05/06/TELEMMGLPICT000315435573_trans_NvBQzQNjv4BquPWyIgZxRyxNFWH7juMhtHTmqhJKAznjTj8BNvOsbjw.jpeg?imwidth=680)
Ukraine forced to update Himars software after Russia jams rockets
Pentagon source describes effort to outwit Russian electronic warfare experts as game of ‘cat and mouse’
![The first Himars systems arrived in Ukraine in June 2022 and had an immediate impact on the battlefield](/https/www.telegraph.co.uk/content/dam/world-news/2023/05/06/TELEMMGLPICT000315435573_trans_NvBQzQNjv4BquPWyIgZxRyxNFWH7juMhtHTmqhJKAznjTj8BNvOsbjw.jpeg?imwidth=680)
Ukraine has been forced to update the software on its Himars rockets because Russian forces have learned to jam their GPS guidance systems.
Considered one of Ukraine’s most impactful weapons and credited with helping to turn the tide of the war against Russia, Himars have become less effective over the past few months, CNN reported, citing a group of US, British and Ukrainian sources.
One Pentagon source described the effort to outwit Russian electronic warfare experts who have been ordered to counter Himars as a game of “cat and mouse”.
The first Himars systems arrived in Ukraine in June 2022 and had an immediate impact on the battlefield. With a range of up to 60 miles – three times that of most regular artillery – they were able to hit Russian command headquarters and supply depots miles behind the front lines.
Military analysts said that Himars set up Ukraine’s rapid recapture of territory held by the Kremlin around Kharkiv in northeast Ukraine in August and Kherson city in November.
![Ukraine has been urging the US to provide it with Army Tactical Missile Systems, such as this one shown in South Korea. The US has resisted as it is worried that Ukraine may use them to strike Russia](/https/www.telegraph.co.uk/content/dam/world-news/2023/05/06/TELEMMGLPICT000290541208_trans_NvBQzQNjv4BqA7N2CxnJWnYI3tCbVBgu9T0aesusvN1TE7a0ddd_esI.jpeg?imwidth=350)
An intelligence leak from the Pentagon this year showed that the US and Ukraine were giving “high priority” to tracking down and destroying Russian Zhitel R-330Zh jamming stations, which are often deployed in military trucks, ahead of Ukraine’s much-talked-about counteroffensive.
“We will continue to advocate/recommend that those jammers are disrupted/destroyed to the maximum extent possible,” CNN quoted a document from the Pentagon intelligence leak as saying.
The Kyiv-based Ukrainskaya Pravada newspaper reported in April how Ukrainian special forces were mounting missions deep into Russia-controlled areas to hunt for jamming systems and relay their position back to artillery to destroy.
The leaked intelligence report also said that the jammers disabled other “smart munitions” such as GPS-guided shells fired by howitzers, and aerial bombs dropped by warplanes, that have been fitted with the US Joint Direct Attack Munition kit, which converts standard unguided bombs into precision weapons.
Ukraine has received at least 18 Himars launchers and the US has committed to giving it another 20.
Ukraine’s leadership has been urging the US to provide it with long-range Army Tactical Missile Systems (ATACMS), which have a range of 200 miles, but the US has resisted because it is worried that Ukraine may use them to strike Russia, escalating the war.