In September 1962 a nice young man ordered the United States to commit to landing on the moon in eight years. Even though none of the technologies, methods, or materials for doing so existed at the time.

On what basis did Kennedy think that this was possible? Did he have any knowledge of the challenge involved, or was he naive to the issues? How off were his estimates of budget for the program at the time of declaration of the goal? Who were his consultants on the matter, and what were their positions?

This question is not intended to spark discussion of the budget overruns or opposition that the program would encounter during the 1960's. Rather, this question only addresses the information known to Kennedy and other people involved with the decision to commit to the moon landing, in the timeframe leading up to the speech at Rice university. The Wikipedia article for that speech mentions with whom the president had spoken, without providing information on the information (supporting or opposing the landing) that each provided.