The RSA is one of the earliest surface-to-air missiles systems, developed by the Swiss companies Oerlikon-Bührle and Contraves starting in 1947.

Oerlikon had been a leader in the development of anti-aircraft weapons after its purchase of the SEMAG company in 1924, and the subsequent takeover by Emil Georg Bührle the next year.

Their most famous products were the variety of Oerlikon 20 mm cannon that started at SEMAG and underwent considerable further development prior to the opening of World War II.

By the mid-war period, most of the armies concluded that anti-aircraft artillery was practically useless against high-flying targets, and would become completely so with the introduction of jet engines.

The Germans, British and US all began guided missile efforts to fill this role, hoping to replace heavy anti-aircraft artillery.

Development continued, and by the next year twenty-five of the slightly improved RSC-51 were purchased by the US Army as experimental rounds.

It did see some use as a training round, by replacing the warhead with a parachute system that allowed recovery and reuse of the missiles.

[2] The RSA was a long, thin missile with a very high fineness ratio, similar to modern supersonic aircraft like the Concorde.

The RSA solved this by using a second radio signal for beam riding, allowing the tracking radar to have a wider search angle without effecting the accuracy of the missile.