1947: first man to break the sound barrier1953: first woman to break the sound barrier

The first man to break the "sound barrier" was Capt. Charles E. ("Chuck") Yeager, of the US Air Force. He reached this milestone of aviation history in 1947 over the test ranges at Muroc Field in California, now known as Edwards Air Force Base.

Yeager accomplished this feat while flying the first Bell XS-1. Later renamed the X-1, this vehicle was a rocket-powered high-speed research aircraft.

The first woman to fly faster than Mach 1 was Jacqueline ("Jackie") Cochran, one of the pioneering women of aeronautics. Jackie originally worked in the cosmetics industry and was encouraged to pursue a pilot's license by her husband in order to travel more efficiently. Cochran managed to complete her pilot training in 1932 in just three weeks! She quickly realized that flying was her passion and set about becoming one of the most accomplished pilots in history. Jackie was the first woman to win the Bendix Race in 1938 and also set several aviation records before 1940, including three speed records and a world altitude record.

Jackie's successes allowed her to become an accomplished test pilot setting many more firsts. As World War II approached, Cochran worked to encourage more women to join the war effort. The British Ferry Command hired Cochran to recruit women to fly planes from factories in the US to bases the UK, and she became the first woman to fly a military bomber on a transatlantic flight in 1941.

Jackie convinced Eleanor Roosevelt, wife of President Franklin Roosevelt, to support efforts encouraging greater participation of women in defense positions. In 1943, Cochran was named director of the Women's Air Force Service Pilots (WASP). WASPs proved vital to the war effort, and Cochran helped to train over a thousand auxiliary pilots for the military services. After the war, Cochran was awarded the Distinguished Service Medal for her contributions.

Jackie remained committed to the defense effort after the war and earned the rank of lieutenant colonel in the Air Force Reserves. She continued to pursue her passion for flying and became a close friend of Chuck Yeager. Yeager helped Cochran make the transition to jet-powered aircraft, and she wasted little time setting new records. In 1953, Jackie flew an F-86 Sabre past Mach 1 becoming the first woman to break the sound barrier. She went on to set a world speed record of 1,429 mph in 1964 and no fewer than eight speed records in 1967 when she was over 60 years old.

An interesting historical sidebar concerns the term "sound barrier." When a British aerodynamicist named W. F. Hilton was interviewed on his high-speed experimental work, he was quoted as describing "how the resistance of a wing shoots up like a barrier against high speed as we approach the speed of sound." The newspapers of the period misconstrued his statement to mean that there was some sort of physical barrier to travel at or beyond the speed of sound, so no aircraft would ever be able to reach those speeds.

In addition, there was some theoretical work done that had indicated the pressures generated on a body as it neared Mach 1 would go to infinity, and the drag would therefore be so great that no aircraft could pass through the barrier. However, these equations turned out to be based of faulty assumptions that were not valid at transonic speeds.

Indeed, engineers had known for many years that the speed of sound could be passed simply because cannon balls and bullets were known to pass through the sound barrier as far back as Isaac Newton's day. The key to finally reaching Mach 1 was simply developing ways of minimizing the increase in wave drag at transonic speeds, developing engines with enough power, and understanding the effect of shock waves on wings and control surfaces so that control problems could be avoided.

The shape of the fuselage on the X-1 research plane had been designed to resemble a .50 caliber bullet since this object was known to exceed Mach 1. Other projectiles, like shells and cannon balls, had also been able to travel faster than the speed of sound for many years. However, it is not known for sure when the earliest projectile exceeded the speed of sound or when guns and cannons might have become powerful enough to accelerate an object to such speeds.

Regardless, another object that has been around far longer than gun-launched projectiles was probably the first manmade object to exceed the speed of sound. Believe it or not, this object is a whip. As the whip's user snaps his wrist back and forth, it sends a wave down the length of the whip that accelerates the tip to very high speeds. This speed can grow fast enough to exceed the speed of sound, particularly if the whip is relatively long.

Whips are known for the distinctive cracking noise they make as the move through the air. This crackling is actually the result of a miniature sonic boom being created by the tip as it travels faster than Mach 1. (info from Aerospaceweb)