MTA launch event, 2018-10-27

The Reaction Research Society (RRS) held another launch event at our private testing site, the Mojave Test Area (MTA), on October 27, 2018. We had a really big day in hosting a launch event for Weigand Elementary School and supporting the projects of several of our members. This was one of the more perfect days for a launch. The day time temperatures stayed below 90 degrees Fahrenheit and the winds were nearly still the whole day.

Old Glory slowly waves in the light breeze of the cool late October morning in the Mojave Desert

Our pyro-op for the event was John Newman, of the Friends of Amateur Rocketry (FAR) group.

Friends of Amateur Rocketry – webpage

John allowed myself, Dave Nordling, and Larry Hoffing apprentice under him for the event as we are both in training to become licensed pyrotechnic operators in California.

John Newman (right) from Friends of Amateur Rocketry (FAR) talks with Mr. Oswald (left) and Dr. Kasparian (middle) at the RRS MTA, 10/27/2018

John Newman (left, behind the wall) and Larry Hoffing (right) oversee the loading of micrograin propellant at the RRS MTA

The RRS welcomed Weigand Elementary School and the Los Angeles Police Department’s (LAPD) Community Service Program (CSP). They had just finished the six session program and had ten (10) alphas ready to launch.

Frank Miuccio shows one of the two RRS blockhouses to the students of Weigand Elementary School

RRS member, Michael Lunny, had come out to the MTA the week before to help Osvaldo with mixing of the micrograin propellant. The simple mixture of zinc and sulfur powders is relatively safe, but requires time to properly mix and load. With the larger demand for alpha rockets with school projects and our growing membership, it’s no longer a process that can be done in the early morning hours before launch day.

Osvaldo Tarditti and Michael Lunny at the RRS MTA, 10/27/2018, having done the hard work of loading the rockets the week before

The ten alphas from Weigand Elementary and Michael Lunny’s alpha in white, all loaded, tagged and ready to go

RRS member Alastair Martin was at our event doing a great job in video-recording many aspects of our event. Alastair and Bill Janczewski, both newly elected to the position of Media Coordinator at the RRS, have been helping expand the presence of the RRS in social media and to the public at large.

Alastair Martin, armed and ready, in the RRS MTA blockhouse

Alastair gets his camera ready for the next alpha launch

Alastair got a lot of great shots and video-footage which I’ll share as they come in. Some of the short videos and photos from the 2018-10-27 event are already posted on the RRS Instagram page.

Follow the RRS on Instagram – ReactionResearchSociety

Just before the briefing, two of our new members had the chance to experience loading their own alpha rockets with the micrograin propellant. Xavier Marshall and Wilbur Owens were coached in the process and got a first-hand feel for classic micrograin rocketry. Michael Lunny’s alpha rocket was already set to go the week before when he helped Osvaldo load the ten alphas for Weigand Elementary.

Wilbur Owens loads his alpha rocket, one cupful at a time, gently bouncing out the air pockets as he goes

Once the alpha propellant tube is full of propellant up to the bolt holes, Xavier Marshall prepares to install his nozzle with the electric match and burst disk which retains the powdered propellant inside

A close-up view of the alpha nozzle with its plastic burst-disk and electric match resting on the interior side, the electric match wires protrude out the bottom (held back by carpenter’s tape just for convenience)

[SAFETY BRIEFING]

We conducted our safety briefing at the beginning of the event before all present. We discussed the many natural and man-made hazards to help everyone become aware and be more safe. John Newman made us aware of a native species of snake, the Mojave Green Rattlesnake, which is sometimes known to become aggressive when discovered. The Wikipedia page is linked below.

the Mojave green rattlesnake

Mojave Green Rattlesnake – Wikipedia

Frank also reminded everyone about keeping their distance from the Desert Tortoise, which is a federally protected species that is also indigenous to the Mojave desert and the MTA. It isn’t very common to see these animals during the height of the day, but everyone needs to be aware and take heed of their surroundings to protect themselves and the environment.

The federally protected Desert Tortoise

Desert Tortoise – Wikipedia page

Besides avoiding heat exhaustion and spiders, collecting and properly disposing of trash, and maintaining their hydration, all attendees must remain under the cover of our reinforced bunker during hazardous operations. With the conclusion of the briefing, we proceeded to a propellant demonstration to show the combustion process on a sample of composite propellant and micrograin powder.

Small sample of composite grain propellant burns hot enough to cut through the steel case supporting it, slow burning but very potent

The bright yellow plume of burning micrograin propellant, zinc and sulfur together go up pretty fast

The next step was getting everyone into the bunker, while John Newman conducted the event as our pyro-op. Larry and I were on hand to assist in the loading and readiness for firing. The RRS alpha had a steel box frame launcher which is our preferred method of guiding these speedy metal rockets up and downrange west.

We got started loading them into the rack by the numbers. The kids did a great job of painting them and making them their own. Most importantly, they label them with large numbers. The color of the fins matter the most since that is the only part left sticking out of the ground at the end of flight.

First of ten alphas right at liftoff

Same rocket just a few frames later

After launching all ten of the rockets, we all took our lunch break. The day was very pleasant, but we all enjoyed a little bit of shade. After lunch, LAPD CSP packed everyone up for the long drive to Los Angeles.

Frank talks with the kids of Weigand Elementary after having lunch after a great launch

[MEMBER PROJECTS]

We started working on membership projects starting with launching Michael’s alpha. It’s always rewarding to launch your first alpha and it’s an experience that never gets old. It’s usually one in a series to come. Big thanks to Michael for helping the society get ready for the event.

Xavier Marshall tried a new approach to launch by allowing me to use the fly-away railguide that I had customized for the 1.25″ RRS alpha propellant tube. Additive Aerospace makes many standard models which this one was derived from the 38 mm design.

Additive Aerospace – fly-away rail guides

Xavier Marshall’s RRS alpha clamped into the launch rails

Flyaway railguide clamped around an RRS alpha

Xavier Marshall inspects his first alpha as it sits on the rail

The first rail launch of an RRS standard alpha was successful. The flyaway railguide seemed to hold as the micrograin rocket sped off the rails. We took video from the facing side of the rail to get a better look at the operation. I was able to get one good still from my camera phone video from the blockhouse. You can see the railguide just above the fins as the rocket has cleared the rails so the flyaway railguide has sprung open and now is free to tumble away.

Xavier’s rail launched alpha rocket makes a clean path up the 20-foot guide, rail guide still seen near the rocket just after clearing the rail

The railguide fit to the alpha very well but the rail buttons were a little sticky as the rocket was slipped into place. I think the dusty aluminum rail is more to blame for this. The workmanship on these flyaway railguides from Additive Aerospace is quite good. Flying one of these devices with a micrograin rocket was expected to be challenging given the high acceleration that micrograin rockets are known for.

The railguide was not recovered intact. I recovered most of the pieces and the plastic end pieces showed fractures. It’s not clear if the railguide broke on the ground from the fall, but given the spread of the pieces, it could be possible the sudden acceleration of the RRS alpha fractured the lower clamp as the rocket took off. Review of Alastair’s video in slow motion may answer what the failure mode is. All pieces were recovered within 50 feet of the rail.

The recovered pieces of the flyaway rail guide. A successful launch but the mechanism didn’t survive for more than one attempt.

Jack Oswald and his team had a set of sample end-burner motors with their next batch of propellant for burn-rate testing. After setting up the first motor, a key part was missing and the pressure transducer had to be mounted too close to the exit plume. It was expected that the pressure transducer wouldn’t survive the first burn but the test was expected to take good data. The test was executed, but unfortunately the test over-pressurized due to the grain separating from its liner during the initial startup. A lot was learned but the other motors were not able to be tested.

Jack Oswald inspects his test motors as he moves them to safe storage before test

Jack’s BEM test starts out okay. A leakage stream is seen coming out the side.

Just a second later, Jack’s test rig overpressurizes and the nozzle plate pops off

My last photo taken of that day was the last of the three member alphas sitting in the box rails ready to go. Wilbur Owens had the honor of flying his first alpha rocket at sunset.

Wilbur Owens takes a picture of his first alpha ready to fly away

The sun setting at the RRS MTA, Wilbur Owens’ first alpha rocket sits ready to fly out of the rails

With the last of our thirteen alphas flying out, we proceeded with the first firing of the horizontal thrust stand built to test loaded alpha propellant tubes. Osvaldo made some modifications to my stout steel frame adapted to the concrete slab in front of the old RRS blockhouse. Dave Crisalli poured this concrete slab as a working platform in the 1970’s. USC in recent times drilled the slab with 1/2″ female anchor bolts to test small 50-lbf motors. It made sense to use this existing foundation for our horizontal thrust stand.

Matteo Tarditti installs the completed RRS horizontal thrust stand to the concrete slab

Osvaldo uses his 185 lbf son, Matteo, as a quick load cell calibration check as Jack Oswald observes the 1124-lbf ranged load cell output on the laptop in the blockhouse. Awkward, but effective.

After some initial software and operator problems with getting and keeping the S-type load cell calibrated, the system was ready to go.

It has been MANY years since the RRS had made direct impulse measurements of an RRS alpha micrograin rocket, but we felt this hardware would be useful for other similar projects in our near future. Although horizontal testing of a micrograin rocket is not indicative of the actual vertical flight, we felt we could still learn much from this testing.

A simple bottle jack (commonly used for changing an automobile tire) was used as a load cell calibration device (pressure gauge was damaged in handling)

We retreated to the blockhouse and got the testing underway. After two false starts from the bunker, we got the alpha motor to fire in the horizontal position and captured it on video.

The results were good in that the load cell readings were captured and the structure adequately retained the rocket in its very brief (0.4 second) thrust bit. Osvaldo crunched the numbers from the readings we got from the test. Load cell readings indicated we reached a peak thrust of 544 lbf. Burn time was only 0.4 seconds.

This is the raw data from the alpha firing in the (translating) horizontal thrust stand; we need more data

Results from the alpha static firing on 2018-10-27

The RRS is very grateful to Interface Force Inc. of Arizona for their generous donation of the S-type load cell we’re using.

www.interfaceforce.com

An S-type load cell, made by Interface Force Inc.

These devices are not very expensive ($350?? each) and are available in sizes from just 100 lbf to up to several thousand pounds. Button cells are more compact and also work well, but they tend to be more expensive.

The big surprise was that our concrete pad wasn’t as well secured as we had hoped. The pad was only 6 inches thick which means that the slab was only an inch or so beneath the surface. I do recall being told this slab poured by RRS member, Dave Crisalli, in the 1970’s, was only intended to be a working surface and that it wasn’t very deep. USC in recent times had drilled the pad with 1/2″ female anchor bolts for a small 50-lbf.

The concrete slab held fast initially, but suddenly broke free displacing itself by over half its length.

Another observation was that we get a little bit of gas leakage at the end of the burn at the bulkhead. This has been seen in other alpha flight videos and thus it wasn’t a surprise.

Despite the moving target of the whole stand moving, just after the alpha fires, you can see gas leakage at the bulkhead

Osvaldo did not see any damage to the seals when we disassembled the rocket from the stand. This may be a weakness of the seal design but it doesn’t seem to harm performance. More experimentation will shed light on this.

Check out the RRS Instagram page to see this footage. I’ll be uploading it to our YouTube page soon as Instagram has a 60-second time limit for video.

While we were conducting test operations at the MTA, Wilbur Owens located his rocket downrange and started the laborious process of alpha recovery by shovel. Osvaldo’s extractor tool has made short work of this step, but I don’t know if it was available that day?

[PROPELLANT DISPOSAL OPERATIONS]

Jack and his team had a quantity of unspent composite propellant which had to be properly disposed. He had quite a bit from a failed attempt to cast a previous motor that hardened too quickly. The RRS MTA is a good place to do this. With the low winds, we are able to safely touch off the two batches in the waning hours of the day.

The first burn was the smaller of the two. The sun had already set so we were losing the light fast.

The first propellant disposal burn was a bit brighter than I thought but manageable.

With the light almost gone, the second batch lit up the night just for a brief moment before fading.

2nd propellant disposal burn starts off with the last of the daylight fading at the MTA

The second propellant disposal burn at its brightest, but quickly fades as the burn safely completes

[IN CONCLUSION … THINGS COMING UP]

Frank had said that the LAPD CSP is looking to start the next school program in January of 2019. We are very grateful to the LAPD CSP for their continuous support to our classes. The RRS is proud to help the community by sharing the hobby we love.

As mentioned in our last monthly meeting, the next event with the RRS will be our visit to Chapter 96 of the Experimental Aircraft Association (EAA). RRS members, Xavier Marshall and Wilbur Owens, invited the RRS membership to join them at their hangar at the Compton Airport on Saturday morning, November 3rd, at 10:00 AM. The RRS is interested in getting inexpensive shop space that is reasonably convenient to our membership residing in the Los Angeles area. The RRS is looking to help cultivate practical machining skills such as lathe work and milling. Many of our members already have these skills to some degree, but want to help other members become more adept at making their own nozzles, nosecones and other rocket parts.

The next RRS meeting will be November 9th at 7:30PM at the Ken Nakaoka Community Center in Gardena, California. We hope to have Jack Oswald and his team present their results. Despite the failure of the first and only sample hot-firing a great deal was learned which will make the next set of tests more likely to succeed.

September 2018 meeting

The RRS held its monthly meeting for September 2018 this Friday, the 14th, at the Ken Nakaoka Community Center. We were displaced from our usual meeting room, but got the upstairs room F with the window view which was pretty nice. We were well attended, but got a very late start. Meetings begin at 7:30pm. There were several little events at the meeting which did not make the agenda.

Alastair Martin, Bill Behenna and Richard Garcia at the September 2018 meeting of the RRS

[X1]
The RRS was glad to welcome new student member, Bailey Cislowski. We had a short little social event at the end of the meeting which was a nice way to end the week.

Bailey Cislowski and RRS VP, Frank Miuccio

Also, the RRS was glad to re-welcome new members Wilbur Owens and Xavier Marshall. Wilbur had his first rite of passage in the RRS by taking his first standard alpha rocket. He’s looking forward to filling it with micrograin at the next launch event on October 27th. It will be one of many to come!

Xavier Marshall and Wilbur Owens; Wilbur gets his first RRS alpha

[X2]
Xavier invited the RRS to come tour the Experimental Aircraft Association’s local chapter at the Compton Airport. The EAA holds regular events including educational events with local kids.

Experimental Aircraft Association, Spirit of 96

Contact information for the local chapter of the Experimental Aircraft Association in Compton

[X3]
RRS member Alastair Martin is active with the Mars Society which just completed their 21st annual International Mars Society convention at the Pasadena Convention Center. If Alastair can oblige at our next RRS meeting, I have asked him to give the RRS a report on his experiences at the event.

Mars Society – home page

Besides film-making and photography, another one of Alastair’s talents is screen-printing on shirts. I recently had the RRS logo added to this bright-yellow shirt that I bought to better survive the hot Mojave desert climate of the RRS MTA. These bright-yellow “Ultra-Club” cool & dry shirts can be bought on Amazon in a variety of sizes besides the “XL” that I wear.

The RRS logo proudly worn on a fall afternoon

[X4]
I recently purchased a fly-away rail guide from Additive Aerospace. This company specializes in model rocketry parts including this simple clamp-on device that obviates the need for mounting rail buttons on the smaller rockets.

Additive Aerospace – fly-away rail guides

Additive Aerospace was nice enough to customize their standard 38mm design to fit the slightly smaller (1.25″ diameter) RRS standard alpha propellant tube. The fit check was perfect and the next step will be to attempt to launch an alpha from the 80-20 rail launcher we have.

Flyaway rail guide customized for an RRS standard alpha micrograin rocket is a good fit (and held closed by my hand).

Flyaway rail guide has two pairs of rail buttons to hold the rocket on the launch rail.

The flyaway rail guide is spring-loaded to open once the rocket travels up and off the launch rail, then simply falls away as the rocket speeds off

1.5-inch 80-20 aluminum rail extrusion, rail buttons are guided down this path on the rocket’s way up and away

12-foot aluminum 80-20 rail launcher, RRS MTA bunker in the background

[X5]
Osvaldo completed the cylinder piece of the ballistic evaluation motor (BEM) assembly that I designed for testing the burn rate of solid propellant samples. I forgot to bring the graphite nozzle pucks that Richard Garcia made for the assembly. Once the gaskets are fitted and the pressure transducer is checked out, we can begin to prepare 4-inch long samples of propellant into the 3/4-inch PVC tubes for which the BEM was designed to fire. This will be a useful tool in characterizing the AP/HTPB/Aluminum solid propellant batches that will be used in the prototypes of the SuperDosa project. Larry has already made a small batch of the RRS standard recipe solid propellant. Some of these first grains may be used in the propellant burn demonstration at the next RRS MTA launch event.

RRS BEM cylinder sits on top of the bottom plate, top plate in the background

[X6]
Thanks to Osvaldo again for his help with the two-stage alpha rocket that I designed. In this prototype, the payload tube was made longer for the possibility of a parachute recovery system for the upper stage. The 1-1/4″ PVC pipe was machined down to 1.600″ OD to fit inside of the standard alpha’s aluminum payload tube. The steel nozzle design, although simpler to make, may prove to be excessively heavy and throw off the mass balance of the rocket. The graphite nozzle design with its split retaining ring may be the better choice. More work is needed before attempting to fly this prototype design including completing the inter-stage timer circuit for deploying the in-line second stage motor in flight.

Two-stage RRS alpha rocket; second stage with a small AP/HTPB/Aluminum solid grain motor

[X7]
Since August, Osvaldo has made some progress in testing the load cell that will be used in the horizontal thrust stand. The bottle jack he used was tapped with an analog pressure gauge and the compression load into the load cell can be accurately measured. Despite some seal leakage problems with the older bottle jack, the results he and Matteo gathered from his data acquisition unit showed our S-type load cell matches the calibration sheet fairly well.

Load cell compression testing rig using a pressure gauge and a bottle jack

Finally, we got to some of the originally scheduled agenda topics:

[1]
Frank Miuccio gave an overview of the next educational event that had its first event of the series held today at Weigand Elementary school. This is the latest in the series of events we’ve had with the LAPD CSP program. The final event will the launch of the alpha rockets at the RRS MTA on October 27, 2018. Dave Crisalli will be our pyro-op at the event.

Osvaldo, Larry and Frank listen at the September 2018 meeting

[2]
We didn’t have another launch event planned yet for this year, but it’s always possible.

[3]
Richard Garcia gave a brief overview of his successful hot-fire test of his 1000-lbf kerosene-LOX motor on August 18, 2018. His pintle injector with an ablative chamber insert worked very well despite a leaking fitting at the LOX port. Some of the equipment did not work completely as hoped, but the overall test produced a stable thrust profile and clean cut-off. Richard put a lot of work into this first design which helps pave the way to the RRS standard liquid rocket project which will remain a regular topic with the RRS moving forward.

Richard Garcia after presenting his liquid rocket testing results; a proud day

Richard then moved into the details of integrating a liquid motor into a rocket body. Using commonly available parts and a few simply made connecting pieces, a simple but effective liquid rocket design can be made with a modest budget easily affordable to universities and individuals. This is still a work in progress, but the RRS is committed to bringing this project to fruition. We look forward to the next engine build which will likely be in a series of builds that will ultimately lead to the RRS standard liquid rocket design.

Richard’s Solidworks model showing both propellant and pressurant tanks plumbed into the rocket body

[4]
We had a very short discussion about the RRS expanding our roster of pyro-ops. Chris Kobel of ROC presented at our August meeting and gave a lot of practical advise on this subject.

Many of our next member “class” including myself have already written their rocket resumes to describe their experience with rocketry and have begun soliciting licensed pyro-ops for recommendation letters which is not a task to be taken lightly. Beyond the RRS regular and lifetime membership, the Rocketry Organization of California (ROC) was willing to help RRS members learn and earn their recommendation letters by attending and participating at events at ROC. The Friends of Amateur Rocketry (FAR) have also been very helpful to those of us who are aspiring to be new pyro-ops. The rocketry community is a small one and it is good to have the support of like-minded organizations to keep the membership across all societies safe, strong and active.

ROC holds monthly events on the 2nd Saturday of each month. I have been working on organizing a group of RRS members to go out to the next ROC event to get to know our smoke-and-fire sisters and brothers.

Rocketry Organization of California – Roctober event on Oct 13-14, 2018

To all of our membership interested in making this trip to the Lucerne Valley on October 13th, contact the RRS secretary. If we have a good number of people interested, we can make this a worthwhile trip. This trip would be on the Saturday immediately following the RRS meeting on that Friday night (Oct 12th). ROC will be holding an event with school kids, but if the RRS members bring their rocket resumes we may be able to have a conversation with the ROC leadership and get some advice and training. If we get a few members to ride out, I’ll contact ROC to let them know we’re coming. Please let me know by Friday, September 28th.

[IN CLOSING]
Next meeting of the RRS will be October 12th, which is always the 2nd Friday of the month. The quarterly update for the SuperDosa project will be part of the agenda as well as several items we did not cover in our agenda. All RRS members are welcome to make suggestions for discussion topics at future meetings. For those wanting to add topics, please let me know. I will post the preliminary agenda topics at the 1st of the next month on the RRS website Forum page.

As always, please keep your email and contact information up to date with the society. We’re glad to see so many new members and returning members. Even if you can’t make it to Gardena on a regular basis, just send us a line to say “hello” and tell us how you’re doing.

secretary@rrs.org

July 2018 meeting

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.

[1]
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.

[2]
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.

[3]
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.

[4]
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.

[5]
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.

[6]
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.

SuperDosa-mockup (2)

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.

[7]
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:
Reactionresearchsociety

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.

[8]
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.

[9]
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.

[10]
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.

[11]
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.

[12]
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.

[BONUS]
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.

[IN CLOSING]
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.
secretary@rrs.org