In testing, it was found that the IR guidance signals were blocked by rain, fog or snow, and could be confused by sunlight shining through the rocket exhaust which caused it to scintillate like the command signals. A 25 GHz radio link was proposed to replace the IR system, but never proceeded with as the project "ran into the sand."
The infrared guidance system encountered problems in testing due to weather conditions and reflections from the rocket's exhaust, leading to a proposal for a 25 GHz radio link as a replacement. The project faced challenges that prevented its implementation.