The Bazooka and Particle Analysis
This Tuesday marked the 94th anniversary of the first successful “tube-launched” solid propellant rocket. What does that mean in plain English? By definition, a “tube-launched” solid propellant rocket is the precursor to the bazooka, an army weapon made famous during WWII.
The prequel to the bazooka was the creation of Dr. Robert H. Goddard as a side project for the US Army. Dr. Goddard was an American professor, physicist, and inventor, whose most important scientific discovery was developing and building the world’s first liquid-fueled rocket.
As the United States entered World War I in 1917, universities around the country began to aid in the war effort; Dr. Goddard believed that his previous rocket research findings could be used in military applications. After pitching the idea to the Army and Navy, the Army saw the potential and decided to move forward with his idea.
After about a year of tweaks and revisions to his original design, Goddard and his colleague, Dr. Clarence Hickman, successfully demonstrated his “bazooka prototype” to the US Army Signal Corps in Aberdeen Providing Ground, Maryland on November 6, 1918. Widespread use of this new military weapon was implemented in the early 1940s when the U.S. became involved in WWII.
Particle analysis technology has only been around since the 1970s, so it was not available to aid in the development of the bazooka in the early 20th century. So to honor Dr. Goddard’s work, I would like to provide a theoretical account of how Dr. Goddard could have used particle analysis technology to improve his research during the development of this infamous weapon.
To make a solid rocket propellant work, a chemical reaction needs to take place; the formal name of this reaction is reduction – oxidation chemistry or redox chemistry. The simplest way to describe redox chemistry is this: when two species are combined in one vessel, one species will lose electrons while the other species gains electrons, and the energy from the transfer of electrons initiates the propelling movement – in terms of rocket science, will cause the rocket to propel. It is ultimately a simple reaction that can result in quite a powerful force.
In 1918, propellants were often mixtures or composites of large distinct macroscopic particles. Dr. Goddard would have greatly benefited by using a Laser Diffraction instrument to measure the particle size of the macroscopic particles to determine what size would be ideal for producing his desired result. For example, if Dr. Goddard were experimenting with aluminum powder, he would want to verify that the size of each aluminum granule ranged from 3 to 100 microns. If the micron was size was above or below the aforementioned range, the experiment would have been a failure and precious resources, like time, money and samples, would have been wasted. Particle sizing could have potentially sped up the development of the bazooka by streamlining Dr. Goddard’s research efforts, allowing him to know exactly what size particles were being introduced into his propellants. Faster implementation of bazooka technology could have potentially impacted the results of both World Wars, but I’ll leave that blog to a historian, not a scientist.