The different types of Silo Hardening to protect a missile in event of a direct nuclear (or otherwise) attack against the missile site. I think this is for an Atlas V missile (But I can’t exactly remember).
Earlier on in the Semester, I built a paper model of the R-36-0 Missile. This was the first (And only) orbital reentry weapons system to actually be deployed. Built off of the R-36 Missile, it was named the FOBS (Fractional Orbital Bombardment System). The missile could be launched, and the warhead could be left orbiting until commanded to reenter the Nominal Strike Zone. This would cut down on the actual fueling and launching time of the missile.
Fortunately for the US, the SALT I and SALT II treaties banned outer space weapon systems (But did not ban the intellectual advancement of these systems) and so this weapon was considered Obsolete.
Now, it is used as a re-purposed launch system for satellites with its new name of Tsyklon
You can build the paper model here: