Dave Nordling, Secretary, Reaction Research Society
The pioneering theoretical and experimental work that formed the basis for the modern practical liquid rocket was published 100 years ago today.
A Method of Reaching Extreme Altitudes, by Robert Hutchings Goddard (1882-1945), was published by the Smithsonian Institution, on May 26, 1919. Considered the father of American rocketry, Goddard developed the theory of his work while at Princeton University in 1912-1913 with experiments undertaken during 1915-1916 at Clark University.
This 79-page paper described a series of practical experiments using nitrocellulose “smokeless” powder combusted within an enclosed chamber through a de Laval nozzle both in the ambient environment and under vacuum conditions. This paper also included mathematical derivations to develop a theory of rocket action taking in account air resistance and gravity with the goal of determining the minimum initial mass necessary for an ideal rocket to deliver a final mass of one pound to any desired altitude.
In his research, Goddard sought to devise a practical means to send instruments above the range of sounding balloons (about 20 miles) to explore the upper atmosphere. What makes this work fascinating is how much was known at the time of his paper’s publication versus how much was yet to be learned and become common knowledge in our time. Very little was known about the nature of the upper atmosphere in 1919. Yet, the basic concept of a rocket with a restrictive nozzle was known for centuries in the Chinese civilization and later in Europe with the 19th century British Congreve rockets.
In this scientific work, Goddard meticulously lays out his plan of research and the incremental progress he made to verify each of his claims. Most significant is his first conclusion on page 34 that his experiments in air and in vacuum prove that the propulsive force from a rocket is really based on a jet of gas having an extremely high exhaust velocity and is NOT merely an affect of reaction against the air.
Goddard’s work did not receive much funding during his lifetime. His work in rocketry even invited the ignorant criticism of the New York Times and others in the public which had a profound affect on Goddard in his lack of willingness to collaborate even until his death in 1945. In all fairness, it should be noted that the New York Times did see fit to offer an apology to Goddard 24 years after his death and only 50 years ago (in 1969) in the weeks before the Apollo 11 flight that landed the first two men on the moon by a multi-stage rocket operating quite well in the vacuum of space without a media for the vehicle to react against.
Goddard was awarded two patents in 1914, one for a multi-stage rocket and one for a liquid-fuel rocket. Considered an iconic work of 20th century science, all rocketry enthusiasts, students and professionals owe themselves the privilege of reading Dr. Goddard’s 1919 monograph which would lead to the first successful test of a liquid rocket flight in 1923 and the first successful liquid rocket flight on March 16, 1926 in Auburn, Massachusetts.
Goddard’s early discoveries included the determination that fins on a rocket by themselves were not sufficient to stabilize a rocket in flight. Goddard’s inventions included movable vanes to vector the rocket exhaust stream in flight and a gyroscope-based control system to effectively guide a rocket in flight.
Although relatively unappreciated in his home country, Goddard’s work was noticed by the Germans and in years later leading to their own rocket development program leading to the V-2 ballistic missile used to terrifying effect during the latter portion of the Second World War. During the Cold War, the V-2 was the heritage of the first rockets by the first space-faring nations.
David Escobar, Director of Engineering at Metso Automation
Industrial oxygen is used for many purposes: in a basic oxygen furnace for making steel, water pollution countermeasures, including sewage treatment, habitability and superfund site rehabilitation, and chemical processes such as production of vinyl chloride, nitric acid, epoxyethane and hydrogen peroxide. It is also used for medical treatment, life support in harsh environments and industrial gasses for welding and other processes.
The production of oxygen has risen from approximately 470 billion cubic feet in 1991 to over 1.5 trillion cubic feet in the U.S. and more than 4 trillion cubic feet globally in 2014.
Oxygen is the most common oxidizing gas and is, of course, highly reactive. When dealing with an oxygen-enriched environment, it is important to control the sources of ignition. Ignition can be caused by many things, among them:
Electrical arcs, which can come from electrical equipment or even static discharge
Friction, which can be generated by the sliding contact of materials within the oxygen-enriched environment
Impact of particles or projectiles internal or external to the enriched environment can generate heat
Resonance, which is vibration-induced heating
Heat of compression (HoC) is the most common cause of explosion due to contamination. Heating is caused by the adiabatic compression of a fluid; this is often called auto-ignition.
Auto-ignition is the phenomenon of spontaneous ignition of a fuel source due to the heat generated by the sudden compression of a gas or HoC. When a valve in a high-pressure or high-velocity oxygen flow is opened or closed quickly, the kinetic energy is converted to increased temperature and potential energy in the form of increased pressure. If the temperature generated by the compression exceeds the temperature needed to ignite non-metallic seals or even the pipe itself, the result is a spontaneously explosion or auto-ignition. When this happens in oxygen systems, the effect can be devastating.
Because the HoC is substantial and can generate thousands of degrees of temperature even at moderate pressure ratios, oxygen systems are designed to limit the pressure drops to control HoC and limit temperature within the autoignition temperatures of the system components.
Thus, it is absolutely essential that contaminants, which can introduce lower auto-ignition temperatures than even the non-metallic seats and seals, be removed from any oxygen system. Any method that achieves the desired cleanliness level is acceptable. CGA 4.4 and the recently issued MSS-SP-138 provide excellent recommendations for cleaning processes.
CONTAMINANTS TO BE REMOVED
Basically, anything that promotes combustion or impact product purity is considered a contaminant. ASTM G93 categorizes contaminants into three types:
Volatile Organic Compounds (VOC)
Hydrocarbon-based greases and oils
Water-based detergents and cutting oils
Particles, lint and fibers
Dust – Weld slag, etc.
Specifications vary on cleanliness level, methods and validation, and include how much residue is acceptable, what method of cleaning can be used and what kind of inspection must be conducted.
Mechanical cleaning is used to remove scale, coatings, paint, weld slag and other solid contaminants and can include grit or ice blasting, wire brushing and grinding.
Aqueous cleaning can be with hot water and steam cleaning or alkaline cleaning. Hot water and steam cleaning is effective against water-soluble contaminants, and is normally used with detergent. Alkaline cleaning uses caustic salt in water to create a highly alkaline solution. It is effective against hydrocarbon oils, grease and waxes, and generally is enhanced by agitation and/or jet spraying. Typically this is used for industrial parts washers. This process is greatly enhanced by ultrasonic agitation, but the solvent residue must be removed as well.
Semi-aqueous cleaning uses hydrocarbon solvent and water emulsion, which is effective for removing heavy contaminants from parts like heavy grease wax or hard to remove soils. Emulsion may require agitation to maintain the mixture, and parts must be rinsed before the emulsion can dry. Otherwise, contaminants may re-deposit on the part that was cleaned.
Acid cleaning varies substantially based on the acid used.
Hydrochloric acid is used to remove scale, rust and oxides. and to strip platings (chrome, zinc, cadmium, etc.) and other coatings
Chromic and nitric acid are used to for passivating, deoxidizing, brightening and removing alkaline residues in addition to cutting oils
Phosphoric removes oxides, light rust and fluxes
Acids must be removed completely from the part prior to drying and, depending on the acid strength, may need a neutralizing process.
Solvents can be used without water dilution or emulsion. Alcohol is a common solvent often used to revisit areas of concern identified by black (UV) light inspection. Solvents like alcohol evaporate completely, leaving no residue.
Vapor degreasing is a process in which a solvent is heated until it vaporizes, while the part is maintained at a lower temperature. The solvent then condenses and dissolves contaminants. The part must be oriented so that the condensed solvent can drain from the part by gravity. This method is very effective for inaccessible areas on parts but requires a contained environment for the part during the process.
Any combination of cleaning methods that achieve the desired cleanliness level is acceptable.
Visual inspection can be direct, including white light, which is effective in detecting contamination down to 500 mg per square meter. UV (black) light visual inspection identifies contaminants that fluoresce and is effective in detecting contamination down to 40 mg per square meter.
Indirect visual inspection is done in two ways: wipe test and solvent filtering. A wipe test can identify contaminants in locations that have no direct line of sight. Typically, both white light and UV light are used on the wipe cloth, and are effective in detecting contamination down to 30 mg per square meter. Solvent filtering rinses the inaccessible area in solvent, which is then filtered to capture contaminants. The filter is then visually inspected and can detect 100 ml per square foot of low residue solvent and it also uses white and UV light.
Quantitative inspection is done by evaporating the solvent used for cleaning and obtaining the weight of the remaining effluent. Acceptable levels of residue vary according to user requirements.
Clean room: This provides a designated location where the environment limits dust airborne particles, where clean tools and clean assembly and test equipment can be stored. It can also provide controlled lighting for visual inspections.
Clean test equipment: Pressure test equipment contains contaminants in hoses and pumps. If a test machine cannot be dedicated for clean testing, give special consideration to cleaning of test equipment or alternate testing with clean gas.
Packaging: After cleaning, give specific instructions on how to package the product to preserve cleanliness in shipping and subsequent storage. Consider the role of desiccant as a possible contaminant. Use compatible products or control desiccant to prevent contamination. Consider the addition of actuation and accessories to the valve. Can the actuator be installed and set up without violating the protection? If the protection is compromised, are there procedural steps to identify and remediate any contamination?
Oxygen cleaning is used to remove contaminants that can significantly reduce the temperature of auto-ignition. There are many methods for doing the actual cleaning. CGA 4.4 and the recently issued MSS-SP-138 provide excellent recommendations, but any method that achieves the desired cleanliness level is acceptable. It is important to know what level of cleanliness your standard process produces. Process validation using a quantitative measurement allows the supplier to have confidence in process quality when using qualitative inspections for production work.
Editor’s Note: The following article was posted on April 20, 2015 in Valve Magazine.com. It is reprinted here for the Reaction Research Society (RRS) with permission from the author and Valve Magazine. The information here is very useful in amateur rocketry and is intended to make our readers aware of the importance of a proper oxygen cleaning process for lines and valves. High purity oxidizers must be handled with care and cleanliness is of paramount importance. The RRS would like to thank David Escobar of Metso Automation and Judy Tibbs, Director of Education at the Valve Manufacturers Association and Editor in Chief of VALVE Magazine.
CGA refers to the Compressed Gas Association. Founded in 1913, the CGA is an organization dedicated to the development and promotion of safety standards in the industrial, medical and food industry. The CGA is comprised of over 110 member companies worldwide working together through the committee system to create technical specifications, safety standards and educational materials; to cooperate with governmental agencies in formulating responsible regulations and standards; and to promote compliance with these regulations and standards in the workplace.
For more information, go to the CGA website:
MSS refers to the Manufacturers Standardization Society of the Valve and Fittings Industry. Standard practices (SP) documents are available related to many applications including the standardized practice of oxygen cleaning (ANSI/MSS SP-138). ANSI or the American National Standards Institute has adopted the standard for oxygen cleaning of valves and fittings.
ASTM stands for the American Society for Testing and Materials. It is now an international organization known simply as “ASTM International” with its headquarters in West Conshohocken, Pennsylvania. ASTM publishes voluntary consensus technical standards including ASTM G-93 for the Standard Practice for Cleaning Methods and Cleanliness Levels for Material and Equipment Used in Oxygen-Enriched Environments.
For more information, go to the ASTM International website:
The RRS met for our monthly meeting on Friday, May 10, 2019, at 7:30pm at the Ken Nakaoka Community Center in Gardena, CA. We were not as well attended this month, but we did have three new people join us at the meeting. With Mother’s Day weekend and graduation ceremonies happening at this time of year, many had other commitments.
I must admit my error this week. I did realize too late that my monthly email to announce the meeting was not sent this week. Typically, I do send an email reminder to our active membership list (or anyone else who wants to know) on the Monday before meeting which also contains a copy of the agenda. Next month, I will not forget as this unintended experiment has shown that our reminder emails can be valuable to our membership.
The RRS has our monthly meetings always at 7:30pm on the 2nd Friday of each month. I usually mark my whole calendar each year with all of the 2nd Fridays to avoid schedule conflicts, but this is only a suggestion. Our meeting location is at the Ken Nakaoka Community Center in Gardena, unless otherwise announced in advance.
Also, in about the week prior to the meeting around the first of the month, I will gather up the agenda topics expected for the next month and post . All members are welcome to send their suggestions and ideas for agenda topics. We especially want short topics (5 minutes) on things related to rocketry, chemistry, payloads or just any kind of project you’re working on. The society is about sharing knowledge. Send an email to the RRS secretary or any of the executive council and we can put it on the agenda. Some of our members who aren’t in town have submitted things to be presented at meetings in the past which is also something the society can share in our meeting if the materials are clear enough and sent well in advance.
After calling the meeting to order and the reading of the treasury report, we began our agenda for May and covered most of the topics leaving some for June 14, 2019.
(1) Discussion of the 2019 RRS Symposium
The 2019 RRS Space & Rocketry Symposium held on Saturday, April 27th, was a success. We had a few different presenters this year in our lineup, welcomed a few new exhibitors and were very well attended over most of the day. According to Frank, we broke last year’s attendance by a small margin. RRS president, Osvaldo Tarditti, was very pleased with the amount of support we got from our membership in the night before and early morning of the symposium. Also, the RRS was very glad to have support we did at the end of the symposium in tearing down and cleaning up at the close of the day. These often overlooked simple details make running the symposium a real pleasure even at the end of a long day.
We had our first opportunity to discuss the positive things at the symposium at the May meeting and this took up most of our meeting time. We were very happy to see so many groups come out including Spaceport LA, ROC and two organizations within the US Air Force (SMC at LA AFB and AFRL from Edwards AFB). The food truck vendor was also a great success. Many people enjoyed the pleasant weather and good food we had on site at lunch time. The outdoor exhibits were also a big hit. We are also thankful to LAPD CSP and the Los Angeles county sheriff’s department. The society will take notes to help with improving and expanding our next symposium still in planning for April 2021.
Some things that could have been better was sound quality. It was generally agreed that better speaker placement and the cloth barriers behind our audience rows was not sufficient to dampen out the noise from several running exhibits and the general foot traffic. It was my suggestion that we return to the 2017 format of having our presentations in the separate meeting room in the back and keep our exhibitors in the ballroom and at the main entrance.
We have also discovered that our exhibition seems to do well starting first thing in the morning and lasting until mid-afternoon. However, our audience attendance for our speakers tended to be better starting in the late morning and lasting all the way to the end of the day. The RRS is considering having fewer presenters but keeping the duration and range of content the same. Our audience seems to enjoy the topics that our speakers have been offering, so we will continue in this direction. The RRS will likely discuss more of our member and attendee impressions of the symposium at the next meeting on June 14, 2019.
(2) Terry Price’s presentation on composite materials used in rocketry – delayed to next month
Terry was unable to attend the May meeting, however, he did say that he could join us next month. Terry gave a great hour and a half presentation of composite materials at the EAA 96 monthly meeting in April. I hope he can bring some of the same excitement that he generated at the Compton Airport to our June 14 meeting in Gardena.
(3) Upcoming events at the RRS Mojave Test Area
The rocket build event with Spaceport LA planned for early May was cancelled. We hope to reschedule a similar event with them very soon. The RRS is always interested in supporting these rocket build events with public and private groups if there is sufficient interest. Larry Hoffing is our events coordinator and the point of contact for setting up these kinds of events.
email@example.com – Larry Hoffing
UCLA will be having their rocket launch event at the end of the Spring Quarter 2019 on Saturday, June 1st. Several model rocket motors will be fired as part of Dr. Mitchell Spearrin’s undergraduate class. We have been glad to support UCLA for three years running in hosting this event. The RRS has also been glad to support their liquid and solid rocket motor teams over recent years.
At this same June 1st launch event, Osvaldo and I talked about securing the alpha thrust stand and having a series of static hot fires to generate more thrust curves for our micrograin alphas. From the one and only thrust curve we made, it appears that the RRS standard alpha qualifies as an “I” sized motor. We had a setback last year when the concrete slab to which the rocket and thrust stand was secured proved to be an insufficient foundation to react the swift impulse loading of an alpha. We have this footage of this defective hot-fire test on our Instagram account. It’s almost comical, but we must do better for the sake of safety and good science. Further, we need more data. The RRS does not intend to commercialize the standard alpha, but for the sake of future projects using this vehicle as a test bed, it would be good to have more recent motor performance measurements.
Some of our membership had indicated interest in building payloads to fly inside of the RRS standard alpha rockets we fly at each of these school events. Nearly all of these payload tubes are empty and are available to members able to build and supply their payloads before the event. Contact the RRS president for more details on alpha rocket payload tube specifications.
Frank has confirmed another rocket build event starting this summer in June through the LAPD CSP program. LAPD has been an ardent supporter and our rocket build programs are a big hit with the kids. The final part of the project is the launch event at the RRS Mojave Test Area (MTA). This will likely take place on Saturday, July 13th. We often have at least six alphas and sometimes as many as a dozen rockets at these events.
(X1) A brief word to potential users of the RRS MTA
Our membership is welcome to bring more tests and flights to the manifest. The only requirements the RRS has is that all participants download and submit a Standard Record Form available from the RRS.ORG forms library. This document provides a basic description of the project that members or other authorized attendees intend to execute at the RRS MTA. Supporting illustrations and documents are encouraged to help explain the task and operations for the supervising pyrotechnic operator. Approval of all activities at the RRS MTA are at the discretion of the supervising pyrotechnic operator and the RRS.
For those outside of our membership wishing to use the RRS MTA, the society requires submission of Standard Record Forms for all proposed activities. These must be submitted to the RRS president at least 14 calendar days in advance of the planned MTA event. Details of these tests can be held confidentially, but the RRS must have the opportunity to review, understand and approve all activities at the RRS MTA well in advance of the event. The RRS would prefer to have at least a month’s notice if not more. The RRS has been glad to assist more and more groups particularly with universities, however, we can not always support events particularly when we get little or no advance notice.
In the professional aerospace industry, it is a common practice to schedule a date with the testing site many months in advance and use this calendar deadline to help motivate the team to achieving meaningful results in time for the pre-set date. Scheduling a test date as an after-thought in executing a project often leads to disappointing results. Also, the society strongly recommends that users consider using times of the year other than at the end of semesters or quarters. If an event is planned well in advance, we will keep it on our calendar and can more easily have the personnel and resources ready.
The RRS must coordinate our activities with several parties and the better informed we are and the more notice we have will result in the RRS being better able to serve our prospective membership and clients. For any questions about RRS policy or practices, please contact the RRS president. The RRS is a volunteer organization and will always make our best effort to support rocket programs and projects.
(4) Pyrotechnic Operators for Rocketry in California
The RRS has been on a campaign to get more of our membership to apply and attain their pyrotechnic operators license. We’ve enjoyed a lot of support from many of our licensed membership in getting the necessary letters of recommendation for the application process. The RRS has also been glad to have the advice and assistance of the California Fire Marshal’s office. Osvaldo Tarditti, Larry Hoffing, Drew Cortopassi, Chris Lujan and myself have been in the application process for the rocketry pyrotechnic operators license. At the May 2019 meeting, Alastair Martin indicated his interest in becoming a pyrotechnic operator also. With more pyrotechnic operators on the state roster, there is more opportunity for more groups to conduct events throughout California. The RRS plans to remain active in our support to the public.
It’s with pleasure that I announce that I have attained my 3rd class rockets pyrotechnic operator’s license from CALFIRE this month. This annually renewable license allows me to buy high powered solid motors and supervise launch events within this class of solid motors. I hope to soon announce more pyrotechnic operators at the RRS very soon. The RRS is also very glad for the support of the licensed pyro-operators in our society and outside of our society at Friends of Amateur Rocketry (FAR). It is through the mutual support of all rocketry organizations that we expand our voice in the state and maintain a high standard for safety and the bold tradition of experimentation made possible in the Golden State.
It’s my intention to upgrade my license to rockets 2nd class to be able to supervise and manage the unlimited category of solid rocket motors. The RRS is an organization that regularly conducts flights and testing in the unlimited class of solid motors. Our proud tradition of responsible experimentation in solid rocket technologies has one of our perrennial activities for over seven decades from micrograin to composite motors.
For more information on the licensing process for pyrotechnic operators as it pertains to rocketry, please contact CALFIRE directly.
(5) RRS Constitutional Committee
Now that the 2019 RRS symposium is complete, the RRS Constitutional Committee will begin their task of systematically revising and updating the RRS constitution. This task was approved by the society earlier this year and the committee comprised of two regular members (Larry Hoffing and Bill Janczewski) and one executive council member (Frank Miuccio) were appointed to begin this task over the summer.
The RRS Constitution has been updated periodically through amendments and notices over the years. The society has decided that a full review and incorporation of all changes be made in an update to the constitution to be voted and approved by our active voting membership near this year’s end. The main intent of the committee is to examine the constitution and recommend changes to better reflect how the society operates today. RRS president, Osvaldo Tarditti, did offer a word of caution that the Constitution should not be too specifically worded to over-regulate our operations. He has recommended that the committee take a minimalist approach and the committee will take this under advisement. Frank already has copies of the last edition of the RRS Constitution and amendments. These materials are available to all society members and some may already be on the RRS website.
This new revision will be known as the 2020 Constitution. It is a big effort and the society looks forward to the committee’s draft to be presented at the September 13, 2019, monthly meeting where suggestions and discussions will first commence.
(6) RRS Social Media Improvements – Recurring Topic
Alastair Martin was able to talk a little bit about RRS social media improvements and advertising of RRS events in general. One of his suggestions was that the society examine the use of EDDM (Every Door, Direct Mailers). These are the large postcard advertisements that organizations use to go into the mailboxes of targetted audiences throughout a region. Alastair has used these in the past with some of his events and had great success. The cost is substantial, but the results could be many more people getting notice to come to future symposiums and other large events with the RRS.
I had offered a suggestion that the RRS consider the use of more forms of electronic payment to help our ability to sell items at events or take membership dues and application fees. Venmo is a smartphone application that can be convenient for some to make direct payments to the RRS. The society seemed open to the idea, but it seemed to require further discussion and a vote to implement the change. There may be other means of electronic payment to consider however we must be cognizant of the fees involved and how practical each means would be for the society. We can bring this subject up again at the next meeting on June 14, 2019.
Currently, the RRS only has a PayPal account which is connected to our “DONATE” button on the RRS.ORG website. We encourage new applicants to use the “DONATE” button to tender their application fee ($40) if they desire associate membership at the RRS. Also, for our current membership, annual dues payments are much easier if made through PayPal or using our “DONATE” button. The only we ask for online donors is that they make a note of what the contribution is for and who we have to thank.
The RRS still accepts payments by direct mail to our post office box shown in our RRS.ORG website. The mailbox is not very frequently examined so it is strongly advised that all persons making payments to the RRS by direct mail contact the RRS president or RRS treasurer by email in advance to let them know to inspect the mailbox soon after the mail arrives. It is not uncommon for our direct mail to sit for a week or more.
Lastly, Alastair made mention of the next Rocket Talk Radio podcast which Richard Garcia and I will be a part of on Saturday, May 25th. The subject of this hour-long program will be Robert Truax. Truax was a key figure in 20th century rocketry and an important pioneer in the decades before the so-called “NewSpace” movement.
(7) RRS Participation with the CALFIRE committee on rocketry
The RRS was invited to attend CALFIRE’s review of the state’s regulations and laws on rocketry. Both the RRS and FAR have been reviewing regulations and preparing suggestions for improvements and clarifications to CALFIRE legislation governing the practice of amateur rocketry in California. The state has been very open to hearing from the amateur rocketry community about ideas and common sense changes that would make regulation better for all participants. Osvaldo has been involved with this activity and will soon schedule a separate meeting for RRS pyro-op’s to share and review our ideas. The CALFIRE committee will meet again in November 2019 and the RRS will offer our views on how the law can best serve the public.
(8) Topics for next meeting
Time ran out in the May meeting. Next month’s agenda will include further discussion about the RRS involvement with the base11 organization and the liquid rocket project (LR101) at Tomorrow’s Aeronautical Museum (TAM).
Richard Garcia has indicated his interest in getting the first prototype of the RRS standard liquid rocket motor built and tested.
RRS members have been helping different university groups on their liquid rocket projects and we expect to greatly expand our activities in this area as this year unfolds.
Lastly, the quarterly update for the SuperDosa project will have be made at the July 12, 2019, meeting.
Our next meeting of the RRS will be Friday, June 14, 2019. We will likely have something to share from the MTA launch event with UCLA by then. If there are any corrections or additions to be made to this monthly meeting report, please notify the RRS secretary.