'Jupiter' (i) was a British unrealised series of plans for an assault landing in German-occupied Norway to capture the northern airfields at Banak, Kirkenes and Petsamo used by the Germans for attacks on the Allied convoys transporting supplies round the North Cape to the Soviet ports of Murmansk and Arkhangyel’sk (1942/44).
As early as October 1941 Prime Minister Winston Churchill had proposed an amphibious descent on Trondheim, using a preponderance of Canadian forces, but in the absence of enthusiasm by his military planners Churchill had postponed the notion for later resurrection as 'Jupiter' (i) by a force of five divisions, given military credibility as a means of safeguarding the Russian convoys but intended as a means of liberating northern Norway. Yet again the planners rejected the notion, which was based on the seizure of at least two airfields (accommodating 70 bombers and 100 fighters) in an area believed to be garrisoned by between 10,000 and 12,000 German troops.
The last use of the concept was as a diversion from the Mediterranean theatre, where 'Torch' was being planned. Continued work on 'Jupiter'(i) thus served to attract the attention of Adolf Hitler, who remained firmly convinced between 1940 and 1945 that the Allies intended a descent on his northern flank in this area, and thus kept substantial German forces in Norway throughout the war, even at times when they could have swayed the balance toward the Germans in decisive areas.