Category Archives: Presenting

World’s First Liquid-Fueled Rocket Launch – A Century Later

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by Dave Nordling, RRS.ORG

A century ago, on March 16, 1926, on a snowy field at the Ward farm in Auburn, Massachusetts, an experimental device built by a Clark University physics professor, Robert Hutchings Goddard, made history being the first liquid-fueled rocket to fly. Powered by gasoline and liquefied oxygen, the humble craft flew a modest 41 feet in altitude and 184 feet downrange after a few initial unsuccessful attempts. From this first flight to the start of the American involvement in the second world war in 1941, him and his team made a total of 34 pioneering flights. It wasn’t until after the second world war that his achievements were more fully appreciated and recognized earning him the title of the Father of Modern Rocketry.

Goddard’s early university research with black powder rockets, vacuum hot-fire tests and the use of a de Laval nozzle produced a small rocket engine far more efficient that it’s predecessors in the 1920’s. His seminal work, A Method for Reaching Extreme Altitudes, first published in 1919 by the Smithsonian Press, was pivotal. Goddard recognized that lighter structures would result in higher final velocities and recognized the value of staging to reaching higher overall altitudes by shedding dead weight along the flight. His work also recognized the value of two-axis gyroscopic stabilization as a means to achieve straighter and more accurate flights. Higher temperatures and better combustion efficiency possible with liquid fuels would make for smaller combustion chambers. Goddard’s notes indicated hydrogen and oxygen having the highest combustion efficiency, but in his first flight, the use of a common and relatively well understood hydrocarbon fuel such as automotive gasoline was likely a reasonable choice. He conducted experiments with gasoline and oxygen combustion starting in 1921 and had a working engine by 1923.

The physical arrangement of Goddard’s first liquid rocket, named “Nell”, was unusual by what is considered common practice today. The combustion chamber with a very long shallow-angle nozzle was at the top with the propellant tanks at the bottom, thus the engine was pulling itself up with the tanks trailing behind. It was thought this arrangement would be more stable in flight. The injection and mixing of propellants in a chamber ahead of a converging path leading to the constriction of the throat area was a major advancement. Owing to conservatism to avoid flow separation of the expected supersonic flow in the downstream diverging portion of the nozzle, the half-angle was very small as was common for the early experiments prior to more detailed knowledge of nozzle geometry. The liquefied oxygen tank sat above the gasoline tank. Wisely, the oxygen tank had a relief valve and a conical hat on top of the oxidizer likely to better divide the exhaust flow. The hot exhaust from the nozzle impinging down on the oxidizer tank would heat the liquid oxygen creating more gas flow to the chamber. His design sought to pressurize the propellants to help feed them by separate fuel and oxidizer lines upward into the combustion chamber. The burning of alcohol-soaked rags surrounding the oxygen tank were used to improve the oxygen gas flow to the combustion chamber. Needle valves in the line offered some ability to balance the relative flow rates into the chamber. The igniter used in the first liquid rocket flight was a closed charge of match heads and black powder that was externally heated by a blow torch on a long pole held by an assistant, Henry Sachs, to achieve ignition and flight. Clark University digital archival documents may have some better descriptions of how operations took place.

“[022] Assistant (Henry Sachs) igniting the rocket, March 16, 1926” by Esther C. Goddard

Later designs as seen in photographs would put the engine at the bottom and tanks forward with tapered nose shapes and care paid to achieving lower aerodynamic drag, higher exhaust velocities and of course higher mass fractions for greater delta-V.

One of the more common questions asked about this 1926 flight was where Dr. Goddard acquired his liquid oxygen. Most likely he acquired it through a commercial supplier, likely what is known today as the Linde Air Products Company. The first Linde plant in the US, an American subsidiary company of the German company, Linde AG, was located in Buffalo, New York, and offered liquid oxygen in 1907. Today, Linde PLC exists from the 2018 merger of the original Linde AG company and Praxair. The details of his handling and loading procedures for the liquid oxygen is something that the society is seeking to discover purely for historical context.

Owing to public ridicule and widespread fundamental misunderstandings of his work, Goddard became very reclusive and many of his achievements were only recognized in the latter years of his life and after his death. Many were inspired by his 1919 monograph, but very quickly uninformed speculation by others led to absurd assertions leading others to deride the young scientist’s work. Most infamously the New York Times claiming “rockets would never work in the vacuum of space” and Goddard was “lacking the knowledge ladled out daily in high schools” only to be serving a post-humous retraction and apology to Goddard 24 years after his death coinciding with the American moon landing in 1969.

Despite some success with the US Army in making portable artillery rockets and an early version of the bazooka, Goddard was very guarded about his work owing to concerns about his inventions being stolen by others including potential funding from companies despite several patent filings. He did much of his later work in relative secrecy in Roswell, New Mexico. Interest in rocketry in the US prior to the second world war was also very modest in contrast to the German government at the time seeking an alternative to traditional guns and artillery pieces limited by armistice agreements at that time. Goddard managed to secure modest funding from a variety of sources throughout the years including the Smithsonian, aviation clubs, the Guggenheim family and famous aviator, Charles Lindbergh, but the amounts considered quite large at the time by researchers were paltry compared to the state funding the Germans secured in the years leading up the second world war. Several groups over the years took note of Goddard’s work but collaboration was slight if not absent.

German rocketry in the 1930’s certainly took notice of Goddard’s work and advanced the science significantly in the years leading to the world’s first ballistic missile, the V-2 (named the A-4 by the Germans). Von Braun and his team took careful notice of Goddard’s work saying Goddard’s work “blazed the trail” for his team to make rapid advancements in Germany. Goddard’s aspirations, like many of the other pioneers of his time including Von Braun, were concerned with space travel starting with exploring and measuring the upper atmosphere. An anecdote I once heard was that when Von Braun was brought to the United States, he was initially surprised how little work was done here, quipping “after all, you had Robert Goddard?” It’s not clear if this anecdote or quote is actually true, but I found it amusing to hear.

After nations realized the potentially devastating effect the V-2 rocket had in the second world war, rocketry and ballistic missiles would become a game-changing technology in late 20th century warfare garnering massive investments in money and materials. Resulting from lessons of the second world war ending in 1945, the ballistic missile era would begin in the early days of the Cold War that follows and in parallel with the founding of NASA and the Space Age in the United States and similarly with the allied nations of Europe and in the Soviet Union. The initial Space Age would lead to further achievements such as the Soviet Union putting the first satellite in full orbit (1958), the first man in orbit (1961), and later the first woman in orbit (1963), followed by lunar probe soft landings (1966) and just 11 years later after Sputnik the first two of twelve American men landing on the moon in six different missions by the United States starting in 1969. Robert Goddard’s work in liquid rocketry being recognized as the seed that would enable the technology making all of this possible.

While some honors and recognition were bestowed on Goddard before his death in 1945, his contribution to science became more widely appreciated in the years and decades thereafter. The NASA facility, Goddard Space Flight Center in Greenbelt, Maryland, bears his name.

Two quotes from Goddard are given below which are something that I found to be particularly relevant even today in the early 21st century:

It is difficult to say what is impossible, for the dream of yesterday is the hope of today and the reality of tomorrow. Just remember – when you think all is lost, the future remains. The reason people fail is not for lack of vision but for lack of resolve and resolve is born out of counting the cost.

Every vision is a joke until the first man accomplishes it; once realized it becomes commonplace.

It’s worth noting that Estes Rockets launched a special hobby rocket kit replicating the initial Goddard rocket design for about $32 USD. This could be a little celebratory fun at the RRS MTA at our next event.

Robert Goddard Model Rocket Kit | Estes Rockets

The RRS honors Robert Goddard in this modest but exemplary achievement in human history. The society was glad to see many well written articles throughout the internet, including one on LinkedIn, honoring this century milestone on Monday, March 16, 2026. This article posted today represents the society’s tribute to one of the most consequential experiments leading to the dawn of the Space Age.

For more information on the Reaction Research Society, please visit our website at RRS.ORG or contact the RRS president by email at: president@rrs.org

Also, the RRS would like to advertise our 83rd anniversary symposium to be held Saturday, April 18, 2026, at the Mary Star of the Sea High School in San Pedro, California. This all-day event will have speakers and exhibits related to amateur and professional rocketry. More information will be posted and can be found by contacting the RRS.

Spark Igniter System for a Rocket Engine

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by Bill Nelson, RRS.ORG

This article describes the simple buzz box design I made for the GALCIT engine replica project done at the RRS MTA in early June of 2024.

For some background, the GALCIT replica engine design was a simple single-port of injection, slab-type of early prototype engine design using liquid methanol and gaseous oxygen. The engine was vertically fired and initially used pyrotechnic igniters set into the narrow diameter throat. After initial tests at the RRS MTA in 2024, just like what the Caltech team discovered in the Arroyo Seco in 1936, we found that pyrotechnic-ignition was too difficult to do given the problem of physical retention of the igniter in the engine. The pneumatic gust from the initial valve openings would eject the pyrotechnic igniters before the chamber mixture could be lit.

From one of the legacy JPL photos, it was clear that an automotive Model-T buzzbox and spark plug type of igniter was installed in the side of a later iteration of the engine design. When the RRS team made this modification, we had success in more reliable ignition of the engine. The problem was how to replicate a technology that has been obsolete for decades. Thankfully, there’s the internet and a lot of hobbyists and tinkerers.

There are many other circuits with lots of electronics that can also be made if someone is so inclined. Most of these use ‘555’ timer chips, transistors, and other solid-state components and can be accessed with a search on the web. I’m sure there are many knowledgeable electronics people that could design their own.

My design uses an automotive (transformer) coil, a capacitor (sometimes called a ‘condensor’), and a 5-pole automotive relay that is a single-pole, double-throw relay (SPDT) type. There is another simple approach which I will describe later.

The circuit I used is very simple. When 12-volt DC power is applied to the relay pin marked ‘87A’ it will switch on and off at a rapid rate until the power is turned off. The relay will energize the automotive coil which in turn will fire the spark plug. As long as the relay is being energized, the coil will continue to produce sparks. This was advantageous to reliably firing the GALCIT replica engine with the liquid methanol and gaseous oxygen mixture. This simple system would most likely help others achieve ignition when other systems might fail. Below is a circuit diagram and a photo of the box I hurriedly made after our RRS team had trouble with the pyrotechnic firing approach. Only one relay was in the firing circuit, the other was a relay to control the circuit remotely from a separate battery.

Another approach uses a coil on plug design. These coils are used in modern cars. Instead of having one coil for all the cylinders, each cylinder has its own spark coil. I have not tried this but it appears to be simpler and have a much greater spark rate and a larger spark. Here is a circuit diagram and picture of one of these systems. This looks much better in my opinion and I will build one to experiment with. The write-up doesn’t say exactly how but I assume the spark pulse is generated as long as power is applied to the circuit.

Both of the above circuits can be found at the link given below, searching under the term ‘buzz box’

gasenginemagazine.com

The first two listings are the ones to read.

There is not much more than this to these buzz box circuits except if you want to make it more complicated and expensive. These circuits just use common sparkplugs, hobby model gas engines (for model airplanes), small engines like those for weed whippers and chainsaws, or even spark ignition systems used in automobiles. There are also specialized plugs made just for rocket engines but much more expensive.

Below are some photos from the GALCIT replica engine in early June 2024 and how the sparkplug was mounted into the chamber interior. This is the middle ring of the modular slab engine design. We had one port drilled for mounting the sparkplug and the other tapped for a pressure gauge which we didn’t use (plugged).

The spark plug we used lasted many firings in the rocket chamber with almost no damage other than some discoloration.

The spark plug can be seen sticking out of the middle ring of the engine. The injector ports are seen in the foreground, one still has a plastic cap covering it. The raised circular port is to mate the engine to its supporting thrust stand shaft as the engine fires upward.

Many liquid engines at the RRS MTA have nozzle-mounted pyrotechnic igniters which can work with the right design, firing sequence and precautions, but there are some significant problems and hazards with this approach.

Modern rocket engines often have their igniters mounted into the injector body or chamber wall near the injector face, but this is easier to do with the greater area available on larger scale engines. Often, these augmented spark igniter (ASI) systems have a small fuel and oxidizer supply to provide a readily ignitable localized mixture to touch off the larger propellant flows in the injector. The picture below is from the Apollo-era J-2 engine. For smaller engines, the igniter is placed directly into the chamber in a location that can reliably and quickly light the initial propellant flows into the chamber.

Most hobbyist designs are smaller where head-end ignition isn’t easy or simply not practical, thus nozzle mounted designs are commonly used.

The use of a spark-plug type of igniter may offer an alternative to pyrotechnic ignition and possibly greater safety against backlighting and hard engine starts or simply catching something downrange on fire after the igniter is spit out. Changing the ‘immersed torch’ design from a pyrotechnic charge to a commercial spark plug design would be straightforward and only require the addition of a buzz box module into the existing firing circuit designs. The RRS may soon attempt this with one of the many liquid and hybrid projects being done at the society.

Dave Nordling and Steve Majdali contributed to this article.

For use of the RRS MTA, contact the RRS president.

IN MEMORIAM: RICHARD GARCIA (1984-2024)

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by Dave Nordling, Reaction Research Society

It is with great shock and sadness, the society announces the untimely passing of society member and our prior director of research, Richard Garcia, on July 5, 2024.

Richard Joseph Garcia was born November 12, 1984, in Visalia, California to Stanley and Michelle Garcia.  He graduated with an associate of arts degree from College of the Sequoias and later from California State Polytechnic University in Pomona in 2007 with his bachelor’s degree in Aeronautical and Astronautical/Space Engineering.  As a professional, he worked for Firefly Space Systems, Masten Space Systems, Aero Systems Engineering, Minnetronix and was an IPT Team Leader at Teledyne-Brown Engineering in Huntsville, Alabama.

Judging from website entries, Richard became active in the RRS before 2013. I came to know him in 2015 and the years following.  During his working years in California, Richard commuted to each of the monthly meetings in Gardena from California City over 100 miles in distance one-way, fighting LA traffic on Friday nights. Richard was a major part of the 2017 RRS symposium, the first in over 20 years which led to the recurring symposium events we now hold in most years.  Richard was responsible for discovering and bringing back the donated LNG horizontal cylinder at the RRS which is soon to become a viable and useful asset at the MTA in this year.  Richard’s residence in California City made him a convenient aid to our Mojave Test Area on many occasions and his machining skills were valuable to other members in their projects.

Through his relentless work ethic and years of reliable support to the society, Richard was appointed as the second director of research at the society, a role only held once prior decades earlier by George Dosa. He retained the role for several years even after leaving California attending meetings remotely during the pandemic and serving the society from two or three timezones away.  He was serving as a committee reviewer on the RRS Regen Engine Competition that started July 1, 2024.

Few could match Richard’s spirit, kindness, intellect, passion and genuine and prolific desire to share and expand knowledge. Richard assisted with and performed numerous projects at the MTA and authored several technical articles on RRS.ORG for the society sharing good practices and helping to make the practice of rocketry safer and more accessible.  He loved the Mojave desert and was a major driving force in the society’s growth in the decade of 2010.  

More locally in Huntsville, Alabama, Richard was active in two hacker spaces and was involved with many projects inside and outside of work. Richard built his own telescope in preparation for the 2024 eclipse earlier this year.

Richard is survived by his wife, Jeannie Riddles, his mother Michelle, his brother Russel, and sister Darleen, nieces Kadence, Kylie, Katelynn and Laura, and a nephew, Leo.  He was preceded in death by his father, Stanley.

No services are planned.  After consulting with his wife, in lieu of flowers, she said that rocketry was Richard’s largest passion and that donations to the RRS could be made in his honor.  Please contact the RRS vice president or any of the executive council if anyone wishes to honor Richard.  The Reaction Research Society Inc., of Los Angeles, California, is a 501(c)3 educational non-profit organization dedicated to amateur rocketry.

vicepresident@rrs.org

president@rrs.org

secretary@rrs.org

treasurer@rrs.org

research@rrs.org

The RRS publicly announced the news to the attending membership of the society at the July 12th monthly meeting at the Compton/Woodley Airport.  The society will email our full membership roster soon.

 A memorial launch event for Richard Garcia at the RRS MTA is being planned for September 7, 2024. Contact the RRS president for details. I will be the pyrotechnic operator in charge. Updates to this article will tell more as it develops.

Ad astra, Richard Garcia.  You will be missed.