Not to be confused with Klaus Riedel ("Riedel II") or Walther Johannes Riedel ("Riedel III"), who were also Peenemünde engineers.
Walter J H "Papa" Riedel ("Riedel I") was a German engineer who was the head of the Design Office of the Army Research Centre Peenemünde and the chief designer of the A4 (V-2) ballistic rocket.
The crater Riedel on the Moon was co-named for him and the German rocket pioneer Klaus Riedel.