Some of these systems were tested in 1987 on the Polyus spacecraft. What was mounted on this spacecraft remains unclear, but either a prototype Skif-DF or a mockup was part of the system. According to interviews conducted years later, mounting the Skif laser on the Polyus was more for propaganda purposes than as an effective defense technology, as the phrase "space based laser" carried political capital. One of the statements is that Polyus would be the basis for deployment of nuclear "mines" which might be fired from outside the range of the SDI components and reach the United States within six minutes.