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Celebrating Dr Robert Goddard’s IP contributions to space exploration

Celebrating Dr Robert Goddard’s IP contributions to space exploration

Published By Sam Mitchell

17/06/2021 16:10:50

Fifty-two years on from Neil Armstrong’s and Buzz Aldrin’s momentous moon landing and the Space Race has returned to the limelight, although those leading the charge are far from seasoned astronauts.  Jeff Bezos is due to become the richest man in space on 20 July when he takes fight on New Shepard – the rocket developed by his company Blue Origin, with Elon Musk’s Space-X program and Sir Richard Branson’s Virgin Galactic nipping at his heels in the race to commercial space travel.

However, all of those men and women who have so boldly gone are undoubtedly indebted to the ingenuity of Dr Robert H. Goddard, who (amongst many other firsts) first theorised that rocket propulsion would work in a vacuum and could therefore achieve thrust in space, the need to use liquid rather than solid fuel, and developed gyro control mechanisms for rocket steering. Perhaps unsurprisingly, he is also known as the ‘Father of Modern Rocket Propulsion’.  

On 9 June 1931, Dr Goddard was granted US Patent 1,809,271 - Propulsion of Aircraft. In celebration of its 90th anniversary, this article provides a brief discussion of the rocket patent.

Rocket propulsion prior to Dr Goddard’s invention relied solely upon the reaction of gases ejected from the rocket for their propulsive effect. In the patent’s introduction, Goddard recognises the inefficiencies in this method, particularly at low altitude where the air is thicker and “most of the heat energy of the fuel, or the charge of the rocket is dissipated as kinetic energy of the ejected gases” and that this leaves a “comparatively small proportion of the total energy available for [propulsion]” when compared to the speed of the gases themselves.

 

Dr Goddard’s invention utilises the ‘tremendous kinetic energy’ of the high velocity gases to drive turbines (7,7’) which in turn operate propellers (10,10’) for driving the aircraft at low altitudes where the air is dense.  In addition to describing a more efficient form of propulsion at low altitude, the invention also describes a means to move the turbine elements entirely out of the path of the blast, meaning that as the aircraft climbs to higher altitudes where the air is thinner (and thus the propellers become useless), the rocket is propelled entirely by the rocket effect.
 
Also of note is the nozzle 3.  Although not discussed in detail in this patent, it is worth noting that Dr Goddard was also the first to use a De Laval Nozzle in rocket propulsion, see his patent US 1 102 635 ‘Rocket Apparatus’, granted 7 July 1914.  This decision transformed rocket propulsion from a mere theory to reality and the iconic conical or hourglass shaped design is still synonymous with modern rocket propulsion. The design works by constricting the ignited fuel through a narrow gap and accelerating it to the speed of sound. Once it has passed through the constriction, it then rapidly re-expands.  This rapid re-expansion causes further acceleration of the gases to supersonic speeds, providing vital additional thrust. 

The presence of certain aspects of Dr Goddard’s innovation in modern rocket design provides a fantastic example of the importance of the patent system, and how the disclosure of an idea to the world in return for a time-limited monopoly is critical to innovation, securing funding and fostering scientific progression.