The V-2 was a small rocket by modern standards. A little more than 45 feet from nose to fins, five-and-a-half feet in diameter, and weighed about 27,000 pounds, it’s payload was a 2,200 pound warhead designed to detonate on impact. It’s engine was a technical masterpiece of its time. High-speed pumps forced large volumes of fuel into the thrust chamber such that the engine produced 56,000 pounds of thrust. This translated into a range of about 220 miles, a maximum altitude between 50 and 60 miles, and a top speed of 3,400 miles per hour. The V-2 broke the sound barrier not long after launch meaning that when it reached its target city — it was launched on London, Antwerp, Liege, Brussels, Paris, and Luxembourg — citizens never heard it coming. They heard the explosion, then they heard the delayed sonic boom.