Through the history and after more than 58 years, the use of outer space for military purpose has always been the first priority for many countries during the beginning of the space age to achieve space science and technology. Today, these activities have led to the militarization and weaponization of outer Space and have set severe security challenges to countries. Islamic Republic of Iran due to different reasons is facing these threats increasingly. Therefore, this study aimed to address assess I.R.Iran's military security threats and there solutions with futures studies approach. In this regard, we have extracted the 14 threats and 16 solutions in two dimensions of space active defensive and space deterrence using by studying the literature and doing exploratory deep interview. Then the impact of the threats and solutions on I.R.Iran's military security was calculated by questionnaire. The results showed that the threats of Identify vital and strategic military areas and signal intelligence collection with 4.05 and 3.90 weighted means and the solutions of utilizing other strategic areas and the development of military doctrine for the acquisition and development of defense space technology with 4.10 and 4.00 weighted means have the highest impact in I.R.Iran's military security.This results should be considered in planning and policymaking of I.R.Iran's defense system in medium-term future.