Physics and Star Wars
To estimate the effects of the second Death Star, Minton looks into its mass. According to estimated data from some students of Lehigh University, the steel mass needed for building one would be around 770 kilograms times the mass cubed in weight. This would give the Death Star of about ten to the power of nineteen kilograms in mass. Using this data, Minton produces equations that lead him to conclude the fragments would hit the moons surface so hard causing craters almost four times the size of the Chicxulub crater in Mexico. This impact would cause a planetary firestorm and vaporize all lifeforms on the moon.
Orange Herald
Two versions were designed - an "Orange Herald Large" with an overall diameter of 39 inches (1.0 m), and an "Orange Herald Small" with overall diameter of 30 inches (0.75 m). The difference between the two was in the size of the high explosives, the fissile cores were similar. Orange Herald Small was intended as warhead for a ballistic missile. Orange Herald Large was designed as device which would have the most certainty to give a yield in the megaton range. However, due to its size it was not suited as warhead for the ballistic missile and was more of an insurance which could be used if other devices failed to achieve the desired yield.