The RRS held its monthly meeting on July 13, 2018 at the Ken Nakaoka Community Center in Gardena. We got a late start (7:45pm), but we were very well attended. New member, Wilbur Owens, brought a friend of his from the Compton Aviation Museum. The RRS accepted a new student member, Bill Behenna. We also had two newcomers from Caltech stop by who were interested in joining the society.
Our July 2018 meeting gets started
We welcomed our newcomers and started our meeting with a very full agenda. Frank brought a new air launcher device he built which operates by a hand piston. We didn’t have time to discuss it but Frank is adding more teaching tools to our educational program to show how much fun even simple rocketry can be.
Frank’s hand pump air rocket launcher
We went a little out of order from the agenda, but we managed to cover all topics in this meeting that ran very late.
The first topic of the agenda was to confirm to everyone that the next launch event at the MTA will be on July 21st. We will host a new group of students completing the RRS educational program. This is another fine group of students from the Watts area and we are grateful to the LAPD CSP program for their continued support of this recurring and successful project. Frank and Larry noted that we will try to get this event started earlier to attempt to avoid the scorching heat of mid-day.
Also, we had a discussion about how to improve the society communications in the wake of a last minute unforeseen change of schedule for a launch event. This was an exceptional case and unlikely to happen again soon, but it did highlight an important aspect of RRS operations which is communicating with our membership. It is very, very important that all active members have their emails with the RRS secretary as the duty to send out the mass email falls to me. There are two ways that the RRS secretary communicates to our active membership:
(1) the email list for meeting agenda notices
I have been building this email list and maintaining it, but I know that I am missing some interested parties. The communication between our membership is still important. Please be kind to other members and pass on the notices and encourage everyone not receiving their emails to let me know to make the proper inclusions. This is a constant work in progress and I am thankful to those who help make this happen.
(2) posting of all launch event dates is on the RRS website
I regularly update the launch date information under the “Forum” section of the RRS website under the “Launches” tab. Modifications to the RRS.ORG website were discussed as a means to make a clearer way for anyone to see if we are “GO” or “NO-GO” before the launch event. I’m not sure what Chris Lujan has in mind, but we will discuss this issue further as time goes on. Effective communication to our membership is important. The use of other social media platforms like Twitter or Facebook were suggested, but it is not clear how widely used these platforms are with our membership that spans many generations of technology adoption.
The second topic from the agenda was my proposal for the RRS to acquire a road sign. This has been approved by the society and the cost is not unreasonable. Placement of a simple sign at the first gate leading into the RRS’s private testing site, the Mojave Test Area (MTA), will make it easier for newcomers to be sure they are going directly to our site adjacent to the Friends of Amateur Rocketry (FAR).
RRS sign at the MTA entrance
The RRS does have a great sign built on top of a metal arch right at the entrance to the MTA built by member, George Garboden, but the society felt a second smaller sign (24 inches tall by 36 inches wide) at the first gate would be another helpful feature to show newcomers the way in.
Proposed road sign for outside the first gate to the RRS MTA
Placement of the sign will be about 10 feet behind the barbed wire fence about 6 feet to the left of our larger metal gate. This should assure good visibility to those reaching this fork in the road.
We had a substantial discussion about the sign content. The results of this discussion are in the sample posted from the website. We also had a substantial discussion about mounting of the sign and the desire to have a solid structure that can withstand years of the gusting winds of the Mojave. The sign quality chosen was of the highest quality to assure a long life under the corrosive effects of Koehn Dry Lake. Richard has suggested that the sign include the RRS logo which I will look into with the vendor. The RRS has given the authority to proceed on this task.
Further to this subject, Richard Garcia has suggested the sign be accompanied by some kind of metal sculpture representing a rocket. This would nicely complement the sign, but this is a topic beyond the original scope of the meeting. In times past, George Dosa had a large metal pipe embedded vertically into the dirt which used to have fins on it like a rocket reaching the end of its ballistic flight. I think the pipe is still there but the fin decorations have been long removed.
The subject of Saturday seminars was only briefly discussed at the July meeting. In past meetings, the RRS has had special presentations made by invited guests. These are very enjoyable to our membership, but they do often run long and consume a lot of meeting time. To be more effective in our meetings, it was recommended that for lengthy presentations, the society ought to schedule a special meeting for our membership on a Saturday morning at the Ken Nakaoka Community Center in Gardena. This way, those of us with day jobs can come to the center before the heat of the day and enjoy the presentations at our leisure. The RRS has identified several potential candidates for these “Saturday seminars”, but thus far, the first session has yet to be scheduled. We will revisit this topic in later meetings. Our vice-president, Frank Miuccio, will be the point of contact on this topic going forward. Updates on this topic will be posted on this website.
The RRS director of research, Richard Garcia, discussed his progress with the RRS standard liquid rocket. This has been garnering a lot of enthusiasm as many universities have been pursuing similar goals.
RRS director of research, Richard Garcia, explains his liquid rocket prototype at the 75th anniversary symposium
The RRS has decades of experience in building these powerful but simplified launchers, but in recent times our activity in this area has been slight. Richard has made a lot of the key drawings, but is still working to finalize the dimensions and proceed with construction. The RRS membership at the meeting had the chance to review his current drawings and make suggestions. Richard will proceed with completing the design and drawings and with the RRS support begin with selection of suppliers, machinists and construction.
Richard’s rocket will use the RRS 15×15 rail launcher that we have at the MTA. The 16-foot rail length should be sufficient to guide the rocket to a stable initial flight. Further aerodynamic study will be needed to finalize the design. Preliminary pictures and features of the design will be discussed in future posts.
The next topic was the subject of pyrotechnic operators and the RRS’s mission to qualify more members as licensed pyro-op’s to expand our ability to conduct events and improve the knowledge of our membership in this important aspect of safety in operations. What we do can be very hazardous, but with the attention to detail and commitment to safety that we have shown over the decades of our history, we are blessed to not have ever had a fatality and very likely to continue this tradition long into the future.
The RRS has identified a few members including myself who are committed to starting the process of becoming a pyro-op with the California State Fire Marshal’s office. The first step is making a request to the Cal State Fire Marshal for their latest package of information which includes a PDF copy of the latest laws and regulations that every pyro-op is expected to know.
California State Fire Marshall rules on fireworks also governs amateur rocketry
In parallel, the RRS is creating a standard package of information for members that include these state provided materials and other resource materials deemed useful by the RRS to properly educate any current or aspiring pyro-op.
The second step in the process is getting five letters of recommendation from licensed pyro-ops of the same class or above the class level you are applying for. The first level of licensing is Rocket Class 3 which is what our new pyro-ops will seek. The final step is paying your exam fees to the state of California, sitting for the exam, passing the exam and getting your license information from the state. It is very important that our membership strive to keep their state license current and not let it lapse. The RRS is indebted to our pyro-ops for making a big part of what we do possible and safe.
Letters of recommendation require a licensed pyro-op to vouch for your abilities to conduct safe operations and a demonstrate sufficient knowledge and competence in all relevant areas for rocketry all in a signed document sent to the state of California. It is not an easy thing to ask of someone who doesn’t know you well. It is not uncommon and very reasonable for many pyro-ops to refuse a request for a letter of recommendation. It is the requester’s sole duty to prove themselves to each licensed pyro-op that they are worthy of their endorsement.
In the past, the RRS had many pyro-ops and by attending MTA events and participating in meetings and other society events, RRS pyro-ops would get to know you and could more easily vouch for your skills to the state. Osvaldo has been successful in securing his letters of recommendation and sending his application to the state. He is now waiting for instructions on when to sit for his examination. This is a process that can take months.
I have also been fortunate to secure letters of recommendation from licensed pyro-ops, but I am still in the process of qualifying in the eyes of other pyro-ops I have asked for their endorsement. It was suggested that the new class of RRS pyro-ops combine our efforts and share our resources. It was also suggested that we ask some licensed pyro-ops to make a presentation at an RRS meeting or special event as a way of educating us in the practical knowledge that they have gained as a pyro-op. Perhaps through these sessions, more of our members can get the letters of recommendation necessary to begin the process.
Dave Nordling assists in the loading of an RRS alpha into the rails under the instruction of pyro-op, Dave Crisalli
It is my intent to encourage the RRS to adopt a more unified approach to gaining this knowledge either by seminar or by apprenticeships that could be offered by other rocketry groups such as Rocketry Organization of California (ROC). I took the action to approach ROC and other amateur rocketry groups about sending a set of our aspiring pyro-op members to a launch event or special training session in the hope to achieve wider endorsement and help build the RRS roster of pyro-ops.
As required since the start of the SuperDosa project, I presented my quarterly update.
To remind everyone what the SuperDosa project is, it is the society’s desire to retake the amateur rocketry altitude record lost in 2004 to CXST. At a height of 380,576 feet (116 km), this is a daunting challenge, but we have a substantial amount of knowledge and experience from our past members to drawn upon. Many boosted dart designs, similar to the SuperLoki or Viper III, are capable of reaching this altitude range above the von Karman line of 328,083 feet and 4 inches (100 km).
Boosted Dart – Viper IIIa
We have decided to begin a long process to build a boosted dart type of rocket and launch it from Spaceport America or Blackrock to retake the amateur rocketry altitude record by aiming for 400,000 feet (121.92 km). This will take several attempts and perhaps a few different designs, but eventually we will succeed.
For comparison, USC recently set an altitude record for a university built rocket of 144,000 feet (43.89 km).
Some of our newest RRS members just recently fired a full-scale solid motor at the MTA with the aim of reaching 150,000 feet (45.71 km).
The vehicle that succeeds in meeting this challenge and restoring the RRS title will be named after long-time member and a mentor to many in the RRS, George Dosa. George was the first licensed pyro-op in California for rocketry and wrote large portions of the rules governing our hobby. George is still active with the society and we are showing our gratitude by using his name for this project.
George Dosa at the 75th RRS symposium in April 2018, third from left
Substantial progress has been made by Larry Hoffing in making sample batches of the RRS standard recipe, although I understand he had to make some deviations to the mixture due to lack of particular chemicals necessary for plasticizing and release from the mold. Addition of accelerants such as iron oxide is not necessarily part of the RRS standard mixture, but it has been used in other mixtures to increase burn rate with good results. The RRS is in the process of re-establishing suppliers for the key materials such as the HTPB binder and the ammonium perchlorate and aluminum powder of different sieve sizes.
Substantial progress has been made with some of our new members and their booster design which was unsuccessfully tested on June 7, 2018 at the MTA. The mixing procedure and some of the equipment necessary for casting larger grains will surely be useful in this sustained effort to build motor of this size. Part of the issue was poor subscale testing to get burn rate data.
The RRS is working on completing a ballistic evaluation motor (BEM) to attain proper propellant curve data which should benefit all society projects using the same solid mixture. I have not had any luck with the getting our top and bottom plate assemblies yet, but I hope my machinist will be available soon to complete all parts well before the next quarterly update.
RRS ballistic evaluation motor design concept
Some of the parts are ready. Richard Garcia was kind enough to turn out the initial set of nozzle pucks of variable throat sizes. I have the fasteners and gasket materials which need to be cut for the seals. The RRS has a 5000 psig pressure transducer and some of the fittings, but we need a short length of clean stainless steel tubing to make the pressure connection. We have a data acquisition unit, but the wiring harnesses needed to be made to route back to the blockhouse.
Chris Lujan has recommended that instead of bringing someone’s personal laptop we get a simple computer like a Raspberry Pi unit to do the data crunching and output the results. The desert environment can be very damaging and it would only take a simple computer to manage the data and output the results. Chris will work on this hardware and software aspect of the data acquisition and processing.
RRS BEM graphite nozzle pucks, courtesy of Richard Garcia
More progress on the SuperDosa progress will be presented in October at the next quarterly report.
The next topic of discussion was led by Alastair Martin. Alastair is a very active member of the RRS and the Mars Society. He is a filmmaker and producer and brings many talents to the society.
Alastair Martin records elements of Richard Garcia’s rocket candy propellant manufacturing process at the RRS MTA, 4/7/2018
Alastair discussed the necessity of the RRS embracing a larger social media presence. The benefits are that the RRS can reach a wider audience, particularly in the younger demographics. Alastair recommended that the RRS open an Instagram account and do work on improving our Facebook page that is already online. Although there are other social media platforms, it was these two services that he has the most success in his businesses.
The use of Instagram can make the society better able to show the world a glimpse of our activities from a select group of our active membership. Instagram is useful for conveniently and frequently posting photos and short videos and is virtually instantaneous. This nicely complements the website we currently use. The RRS approved the opening of an Instagram account.
Once you have the Instagram smartphone app loaded, you can find us at our Instagram ID which is our full name without spaces:
Our society treasurer, Chris Lujan, generated the account and he will be primarily responsible for the RRS Instagram account. The executive council, director of research and events coordinator will be the first members to have permission to post photos to the RRS Instagram feed. The RRS will consider allowing other trusted members to post on our new Instagram account as we go on.
Reaction Research Society on Instagram
The RRS has a Facebook page. I think it is our vice-president Frank Miuccio, that maintains this site. The RRS will strive to post more often on Facebook which is widely used by many people worldwide.
RRS on Facebook
As secretary, I will continue to maintain our world-wide web site, RRS.ORG as our primary means of advertising ourselves and posting updates to activities.
After some debate and discussion, the RRS has decided to proceed with holding the 2019 RRS symposium in April next year. Although it is a substantial commitment of resources and money by the society, the 2017 and our 75th anniversary symposium were successively larger hits with our public audience. We will strive to improve our symposium based on the lessons we’ve learned and use the momentum of enthusiasm built from two very successful events. However, it was agreed that after the 2019 RRS symposium, the society will not hold another for two years. Our commitment to what will be the 2021 symposium will be pending until the year before.
The 2019 RRS symposium is coming in April.
With this decision, setting the date and starting our long process of contacting industry, academia and government speakers will begin. There will be more discussed on this topic in future meetings. We are excited to confirm another symposium and hope to make this event even better than before.
The agenda had originally stated that our next launch event at the MTA with LAPD CSP will be Saturday, July 21st. We circled back to this topic reminding everyone that the safety briefing will be conducted at 10:30 AM and the launch event will proceed at 11:00 AM. It is the goal to have all eight of the standard alphas assembled by the students launched before the heat of the noon-day sun rises. We want to encourage our membership and invited guests to this event to arrive very early which for me means leaving Los Angeles at least before 7:00 AM. Dave Crisalli will be our pyro-op for this event and I have volunteered to be his apprentice unless one of our other pyro-ops in training would like to do so.
I had an agenda item to discuss future events at the MTA including one possible event with a BBC program in the UK. This may occur in October 2018 and discussions are still in work. The RRS will likely hold another educational event with the LAPD CSP in the fall which may be able to coincide. Larry had made contact with the Girl Scouts of Orange County who were seeking the RRS to participate in a regional STEM event. All of these projects will also be discussed further at the next meeting in August 2018 as more information comes in.
Osvaldo gave our meeting audience a demonstrate of his new method of loading micrograin propellant (without the propellant of course). For some background, the RRS standard alpha is a common platform in our society events. They are particularly common with our educational classes that we hold regularly. Based on the micrograin propellant invented by our founder, George James, this simple mixture of zinc and sulfur powders presents a challenge in loading. The coupler is installed with an O-ring seal at the head end. The 3-foot long, 1.25-inch DOM steel tube with four welded sheet metal fins and holes drilled for installing the nozzle is basically an open tube closed at one end.
alpha bulkhead loaded and bolted in
RRS standard alpha configured for propellant loading; nozzle is installed at the end of loading
The 80% zinc and 20% sulfur by weight propellants are premixed by tumbling and is loaded into the propellant tube by hand. Entrapped air is a frustrating factor in getting a tight packing of the propellant into the tube. As the powder falls to the bottom, the air can not completely get out of the way and empty pockets form. These pockets can be released by simple mechanical tapping or gently bouncing the tube vertically on a wooden block. In the finite volume of the propellant tube, entrapped air is a waste of space that could be filled with the mass of propellant. The loaded weight of the alpha subtracted from the empty weight of the alpha propellant tube at the start is the only real gauge of how well packed the propellant is.
Many methods of compaction and casting of the micrograin propellant to achieve higher densities have been tried over the RRS history. Some of these have had success, most did not. This topic is a long subject which can be researched and summarized in a separate article if there is sufficient interest. For now, only the simple method of manually loading the premixed powder will be discussed.
The common method used today is to pour in the propellant mixture one cup at a time and bounce the bottom of the tube on a wooden beam. Vibration devices do work, but they tend to work too well in that the zinc and sulfur being of different densities start to separate which is very undesirable. This method of one cup at a time is slow, but effective.
a cupful of micrograin propellant drawn from the tumbling mixing drum
traditional loading method that carefully removes trapped air by periodic mechanical tapping is very slow and very messy
When the RRS started to run more launch events with schools, loading a dozen or more propellant tubes started to take a great deal of time including coming to the MTA on the night before. Osvaldo who is the main person doing this loading sought a faster but effective means to loading.
He tried a few experimental practices including drawing a vacuum at the bottom of the tube with a special fitting and using a lowered piston on a string approach, both of which were flawed and not that successful.
His most recent method has proven to be very effective and quick. He gets a length of tiny brass tubing and loosely affixes a round cardboard disk. With this cardboard disk inserted into the mouth of the tube and a proper funnel attached, the full propellant load of the alpha can be loaded directly into the funnel.
Rapid micrograin loading by small brass tube and cardboard disk
By allowing the weight of the full propellant load to lower itself into the tube on top of the cardboard disk, the disk serves as a seal to divert any entrapped air beneath up through the hole in the brass tube. The air below the solid powder mass has a route to escape through the hollow tube up the center. With this technique the whole propellant load can drop into the tube in one motion, leaving the cardboard disk at the bottom. The brass tube easily pulls out from the cardboard disk and out of the propellant tube now loaded with the micrograin propellant.
tube and cardboard disk aligned in the funnel in the mouth of an empty RRS alpha propellant tube
Illustration of rapid method of loading micrograin propellant
This technique eliminates the barrier of the air below trying to move past the falling mass of powder and results in a reasonably dense packing of the propellant all done in one shot.
Osvaldo Tarditti and his rapid method of micrograin loading; note the very small but long brass tubing and the extra large funnel to hold the full ~4 lb load of micrograin propellant
I took photos of Osvaldo’s process at the last launch event with UCLA on June 2, 2018. The pictures and illustrations I have posted of the technique that has been successfully demonstrated at the MTA are hopefully clear enough to show the principle.
This was intended to the first topic, but Osvaldo circled back it at the end. Osvaldo successfully flew a parachute system in an RRS alpha. This is a feat that I don’t think has been in done in a very, very long time. Most of our alpha rockets come back ballistically and require back-breaking extraction by shoveling out of the hard-packed dry lake bed. It has been a general goal of the RRS to encourage more payloads to be flown in the RRS standard alphas as we do a lot of these flights. It has been a goal of mine to eventually fly a parachute system in the tight confines of the alpha’s payload tube. Osvaldo developed a pull switch that activates a timer chip inside to delay the firing of a small powder charge that ejects the parachute by means of a rising piston. This was discussed in the details of the same launch event with UCLA on June 2, 2018.
Osvaldo stands behind his RRS standard alpha parachute system successfully flown at the MTA on 6/2/2018
We did not have a lot of time to show all of the parts, but Osvaldo did mention that he will fly his parachute system again at the July 21, 2018 launch event with a modified timer design and break-wire system that is more compact. I may get Osvaldo to write a full detailed article on this subject in a future posting to come. This parachute system if proven to be repeatably effective may become a standard part of our RRS launch events with schools, but we must consider the added costs of producing them with standard costs we already charge for our RRS standard alpha. This is a really good topic and I’m sure we’ll be talking more about this in August.
Richard Garcia treated us to a short video made by Microcosm back in 2001 with their experimental launch vehicle that did engine test at the RRS MTA. This dual-engine liquid rocket had thrust vector actuators and went through a successful hot-firing in the video.
Microcosm’s Scorpius-S-RM-20k vehicle test at the RRS MTA in 2001
The video showed the later rocket flight. We may post this on the RRS YouTube channel for everyone to see. It was a nice way to conclude our meeting with a rocket firing and flight.
We adjourned the meeting very late (well past 10:00 PM) which is only possible due to the kindness of our hosts at the Ken Nakaoka Community Center which closes at 9:00 PM. We are very grateful to them, but the RRS must strive to be more effective in our meetings to start on time and finish on time.
If there are any topics for next month’s meeting, please contact the RRS and make your suggestion. In the August meeting, we will likely discuss the July 21st launch and lessons learned from that event. We also have other events planned for this fall.
The next RRS meeting will be August 10th.
If there is anything I have missed or misstated, please let me know.