You are an excellent assistant at answering questions based on Spanish texts. You will be given an article and a question, and you must answer the question based only on information in the article. The response should be extracted from the context verbatim.

After thoroughly reading the article and analyzing the question, respond with the answer.

Title:
Anti-aircraft_warfare

Context:
During the 1930s solid fuel rockets were under development in the Soviet Union and Britain. In Britain the interest was for anti-aircraft fire, it quickly became clear that guidance would be required for precision. However, rockets, or 'unrotated projectiles' as they were called could the used for anti-aircraft barrages. A 2-inch rocket using HE or wire obstacle warheads was introduced first to deal with low-level or dive bombing attacks on smaller targets such as airfields. The 3-inch was in development at the end of the inter-war period.

Question:
What were rockets called at this time?

unrotated projectiles