 On April 28th, 1945, a small cohort of American scientists arrived in London. They were there to study the German Army's advances in aviation and supersonic missiles. By then they knew about the V-2. The missile had been launched on European cities the year previously in 1944. What they didn't know was that the German Army had been developing two different systems that could bomb American cities from European launch sites. One was Sanger's anti-potal bomber and the other was a variant of the V-2. The A-9 and A-10 missiles. The V-2 was properly known by the men who designed and built it as the A-4, A standing for aggregate. The first two A-rockets, the A-1 and A-2, were small proof of concept vehicles. The next two, the A-3 and A-5, were test beds designed to work out the kinks of the first operational rocket, which was the A-4. The first A-series rockets were sleek with rear fins for stability in flight, but later variations saw some significant design changes, namely the addition of wings. Wind tunnel models and drawings American scientists found revealed the continuation of the series, beginning with the A-6, A-7 and A-8 rockets. Three unbuilt design studies that all featured wings. The A-9 and A-10 were long range versions that added stages to the classic A-series rocket structure. The A-9 was a winged version of the V-2 with a longer range. The A-10 was a far more menacing offshoot. This was an A-9 mated to an 85 ton booster rocket. The booster could generate 200 tons of thrust for a launch speed of 3,600 feet per second. The A-9, which had its own engine, acted as a second stage. Once it fired its own engine, it could increase the remaining payload to 8,600 feet per second. Tearing through the upper atmosphere, this two-stage launch system could propel a warhead 3,000 miles from its launch point. That's roughly the distance from a launch site in a western European city to any city on the American East Coast, like New York. There was even an A-9 variant that had a cockpit, meaning the rocket could become a manned precision bomber. Luckily for post-Second World War Americans, neither the A-9 nor the A-10 was ever launched in combat. Questions or comments about the history of spaceflight and rockets? Leave them below. And for weekly Vintage Space updates, don't forget to subscribe.