The Navy's confidence in Mauler proved misplaced; by 1963 the program had been downgraded to a pure technology development effort due to continued problems, and was canceled outright in 1965. All three of the stakeholders, the US Army, US Navy and British Army, started looking for a replacement. While the British took a longer-term approach and developed the new Rapier missile, the US Army and Navy scrambled to find a system that could be deployed as quickly as possible. Facing the problem of guidance in a cluttered environment, the Army decided to adapt the infrared AIM-9 Sidewinder missile into the MIM-72 Chaparral. This was based on the AIM-9D, a tail-chaser, and would be useless for the Navy where its targets would be approaching head on. They required a radar-guided system, and this naturally led to the AIM-7 Sparrow. They also considered Chaparral for smaller ships due to its much smaller size, but no such fits were ever attempted.