Tag Archives: composite grain

Static Fire Test of Hybrid Motor at FAR, 2021-04-17

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Dave Nordling, Reaction Research Society

Based on the recent lacking performance of the Contrails H222 nitrous oxide commercial hybrid motor, a pair of static fire tests were conducted to improve the ignition and severance of the nylon fill line. The latest of these static firings was conducted at the Friends of Amateur Rocketry site south of the RRS MTA on 4-17-2021. This was done for simple convenience since I was unable to attend the MTA launch event in the week prior. Mark Holthaus and John Newman oversaw my static firing and offered good advice. Fellow RRS member, Dmitri Timohovich, joined me that day and brought his four channel firing box to conduct the remote fill and fire operations of the hybrid.

Dmitri connects the fill manifold to the nitrous oxide bottle at FAR
Orange fill and firing box for the hybrid motor
Fill, drain and firing circuit for a Contrails hybrid rocket motor. The separate vent solenoid valve hasn’t been added. Weight scale is also a separate feature and not necessary for operation.

Nylon is one of the stronger polymer tubing materials which can handle the 900 to 1200 psig nitrous oxide pressure when flow is supplied from the solenoid valve controlled manifold. The problem is that this strength makes it difficult to quickly and cleanly sever the Parker NBR brand, 3/16” OD fill line allowing the nitrous oxide to flow against the fuel grain while getting reliable ignition.

The original ignition method as designed by the manufacturer is a small resistor in place of an electric match and the use of a Pyrodex pellet which is essentially a pressed cylinder of black powder. The first flight attempt of the nitrous oxide hybrid rocket used this method but was not successful.

Contrails Rocketry, H222, 38mm, 16-inch high powered nitrous oxide hybrid motor

Earlier builds of the hybrid motor used electric matches and small scraps of composite propellant grain for a swifter and hotter ignition. The first two flights showed evidence of the fill line remaining connected. A better means of ignition and fill line severance was needed.

February 2021 launch of the hybrid motor in Larry’s 3-inch rocket body. It is clear that a hot plume is exiting the nozzle but the sharp arc to the north seems to indicate that the fill line is still attached.

The composite propellant is an ammonium perchlorate, aluminum powder and HTPB binder mixture with some red iron oxide used as an accelerant. These scraps were from RRS member, Larry Hoffing’s, small solid motor that he unsuccessfully tested at the MTA in 2019.

The Contrails H222 motor was mounted upside down due to the lack of a proper motor retainer feature. The static firing was the primary purpose which resulted in a feeble puncture of the filling line and no subsequent ignition.
The aft end of the hybrid motor mounted for static fire at the RRS MTA on 3-20-2021
Failed ignition resulted from the 3-20-2021 static firing. Disassembly revealed an excessive amount of electrical tape and an uneven burn around the fill line circumference was the most likely cause.
Previous solid propellant grain motor test in 2019 was a failure, but the remaining tailings from the casting were useful in boosting the ignition power in prior hybrid motor tests

The last static test at the MTA failed to achieve ignition and only created a small tear in the fill line without achieving ignition of the grain. The composite fuel grain fragments were getting clean ignition but the electrical tape wrapping method I used failed to adequately focus the high temperatures to getting clean ignition and severance of the black nylon fill line.

At John Newman’s suggestion, we used a small ring of composite propellant grain at the forward end inside the hybrid high-performance (HP) fuel grain. These were made from a 22mm cylinder that was cut to a 3/4-inch length and drilled out to a 3/8-inch hole size which is roughly twice the diameter of the black nylon filling line passing through. This larger hole would allow the electric match head to be in close contact with composite propellant ring. As the solid propellant charge burns it focuses the tremendous heat of combustion on the nylon fill line causing it to soften, extrude and cleanly sever.

John Newman uses his lathe at his shop to gently machine fuel grains for custom applications.
The ring of 22mm diameter composite propellant grain fits within the head-end of the hybrid fuel grain and can be pressed flush to the edge. A 3/8-inch hole is run through the 3/4” long segment to allow the nylon fill line to pass through with enough room for the electric match head
Floating injector (left) with the nylon fill line pushed into the Parker push-to-connect fitting. Composite propellant grain is pressed in flush to the edge and electric match head can be seen beofre it is secured to the fill line to get the proper position when the motor is assembled
Snap ring, graphite nozzle and steel nozzle washer finish the motor grain assembly inside the 16-inch aluminum body of the H222 model
The complete motor assembly clamped into the unistrut holding fixture. The clear vent line at the head end must protrude to the outside to give a visible and audible indication when the oxidizer volume is filled with liquid before committing to firing.
Dmitri Timohovich makes adjustments to the clamps holding the hybrid motor in place. Peak thrust is just above 200 lbf according to the official thrust curve data for this H222 model.
Four channel firing box sits at a safe distance from the static fire test stand.
Dmitri Timohovich (left) and Dave Nordling (right) pose next to the unistrut mounted static fire mounting of the Contrails Rocketry H222 high-powered 38mm hybrid motor ready for testing at the FAR site on 4-17-2021

With everything in place, we called over the pyrotechnic operators in charge for this FAR event. After inspecting the connections and describing the fill and fire procedures, we were authorized to begin the short filling process.

Successful ignition of the hybrid motor at FAR

The hybrid motor was loaded, fired, reloaded and fired again. Both times stable ignition was achieved and the fill line dropped out of the motor as expected. We had to abort the initial second firing as visual confirmation of the nitrous oxide completing fill was not apparent. Given the hybrid motor has a small weep hole in the head end of the motor means that given time the nitrous oxide will leak out safely. The clear 1/8” acrylic vent line had become tangled in the unistrut obscuring the liquid plume. Trimming the acrylic vent line helped to keep the tip more visible on the second and last firing that day.

Cheap and simple, the 3-inch Little John from Mad Cow Rocketry

The next step will be to purchase a 75mm rocket body able to integrate the 16-inch long, 38mm standard hybrid motor inside. The 3-inch Little John rocket from Mad Cow Rocketry was selected and should arrive soon. With luck, the rocket can be built and ready for 1010-rail launched flight at the next RRS MTA event on 5/1/2021.

The RRS is thankful for the support of FAR at their facility for this static fire. Dmitri and I conducted a safe dispoal burn of the scrap propellant. I was able to acquire a few more propellant ring segments for subsequent tests of the hybrid in flight. Later, we plan to revisit the Pyrodex black powder charges with the electric resistors as the initiator. It is not clear if this will be as effective as the high temperature composite grains and an electric match, but it is worth a try.

MTA launch event, 2018-10-27

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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.

October 2018 meeting

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The RRS met for our monthly meeting on Friday, October 12, 2018, at the Ken Nakaoka Community Center in Gardena. As usual, we got started by calling the meeting to order and reading the treasury report. We had a big agenda but covered most of the topics.

[X1]
Richard Garcia wasn’t able to join us at the October meeting. He wanted to report that he has made some design improvements to the RRS standard liquid rocket. He’s finished upgrading his engine design code to be able to analyze a blowdown engine (pressure-fed from the tanks). He also will soon have drawings for a thrust chamber design.

With some luck, I hope he’ll be back into testing at the MTA sometime soon next year.

[X2]
Electro Tech Machining (ETM) in Long Beach, California, specializes in graphite stock, graphite parts and Electrical Discharge Machining (EDM). They are experts and have been a loyal supporter of amateur rocketry groups such as UCLA and USC. The Reaction Research Society is happy to endorse them as they have been a great support to our society member’s projects as well.

Electro Tech Machining – Long Beach, contact information

Contact Cathy Braunsdorf at Electro Tech Machining.

Electro Tech Machining
2000 W. Gaylord Avenue
Long Beach, CA, 90813
(562) 436-9281

Electro Tech Machining in Long Beach, the graphite specialists

Electrical Discharge Machining (EDM) – Wikipedia article

I stopped in this week to pick up some round stock for making more graphite nozzle pucks for the ballastic evaluation motor (BEM) that is nearing completion. Graphite makes an excellent high temperature material for nozzle throats or any low ablation surfaces. We have used graphite inserts into reclaimed alpha and beta nozzles over the years at the RRS. Our society members have used graphite throats in their larger solid motor tested at the RRS MTA back in June 2018.

Plastic nozzle puck used for scale against the graphite round stock acquired by the RRS from Electro Tech Machining in Long Beach, CA

Moving into the meeting agenda, we shifted the order a little, but I have kept the numbering the same:

[1]
The latest educational event at Weigand Elementary school in Watts is going very well. The LAPD CSP program continues to help sponsor the event and we get great excitement from the kids. This Friday was the fifth of six educational events where they get to assemble the empty rockets. Osvaldo, Larry and Frank were on hand to help with the build process. The kids are really enjoying the process of learning and painting the team rockets will done in the last session before going out to launch at the RRS’s private testing site, the Mojave Test Area (MTA).

Two of our young participants show their assembled RRS alpha rocket at Weigand Elementary, Frank Miuccio in the background at the right

[2]
The next launch event at the RRS MTA will be the final step in the RRS’s educational program for Weigand Elementary school. We have this scheduled for October 27th and we hope to have cooler weather than in prior events now that the summer has passed. We have nine alphas from Weigand Elementary and three more alphas from our new membership, Wilbur Owens, Xavier Marshall and Michael Lunny.

Xavier Marshall looks over his first RRS alpha, welcome to the club!

[3]
I gave my quarterly briefing on the SuperDosa project at the October meeting. This time, I organized my thoughts and ideas into a presentation to give the RRS a general overview of the project and where we are so far.

Largely, I wanted to reiterate the project’s overall goals to many of the new members who have joined the RRS since the project’s inception in January 2017. The RRS intends to retake the amateur rocketry altitude record and in the process reopen our ability to make larger solid rocket motors and expand our reach both in our own community and literally with payloads ultimately flying above the atmosphere.

SuperDosa quarterly report, Oct-2018

I also acknowledged the recent progress of some of our new members formerly of the Chaminade Rocketry Club. Also, USC had a launch attempt with their Traveller III rocket, part of their Spaceshot Initiative. Unfortunately, instrumentation was not functioning but the flight looked to be nearly perfect. I hope USC will come present their recent accomplishments at a future RRS meeting.

Materials acquisition and some discussion about how to proceed with the propellant burn rate testing were the highlights of the discussion. More progress needs to be made in a few areas for completing the first prototype:

(a) Complete the design of all parts for the first prototype (6-inch booster)

(b) Begin prototyping instrumented dart payloads to practice flying and recovering these while getting good data. Making these devices work under the tight and unforgiving conditions that they must.

(c) More work in parachute recovery

(d) Estimating friction heat loads and heat mitigation strategies for the payload

Much of this prototyping work can be done at the MTA by flying smaller subscale vehicles and testing subsystems to prove they can work. More importantly, these tests give the society practice for the large vehicle testing which will reclaim the altitude record for the RRS.

The response to the SuperDosa project’s progress was very constructive and many new ideas were offered. I’m thankful to Frank, Steve Majdali, Larry, Osvaldo, Bill Behenna, Drew and Xavier for their inputs. I have taken notes and given actions to other members who are willing to help advance key areas of the project. Unfortunately, this topic was to be the last of the evening as my presentation easily exceeded the 20 minutes I intended.

The next quarterly report for the SuperDosa project will be January 11, 2019, and I hope to report a great deal of progress.

[4]
We had a last minute addition to the agenda, with Steve Majdali talking about black powder rockets and some very nice black powder rocket making tools he acquired while on travel. Black powder rockets are a classic form of amateur rocketry and involve many techniques that are broadly useful in other areas such as composite grain motors.

Steve Majdali shows the RRS his metal spindle for a cored grain type of 3-inch black powder rocket

Steve gave us a lot of great information specific to black powder making, pressing and a wealth of other practical information. Based on this new avenue of research, I felt the RRS would benefit more if Steve discussed this topic in more length in a stand-alone article soon to be published here on the RRS.ORG website.

[5]
The RRS has been in contact with the Additive Rocket Corporation (ARC) of San Diego. They are a startup company in San Diego with the goal of making high performance rocket motors using their novel design methodologies and 3D metal printing equipment. Discussions are still underway and thus there wasn’t much to tell. ARC was an exhibitor at the 75th anniversary symposium this year in April.

Additive Rocket Corporation (ARC) of San Diego at the 75th anniversary RRS symposium

[6]
In my discussions with ARC, they were kind enough to offer to 3D print a simple small liquid rocket chamber I designed. Prices are not cheap, but this futuristic manufacturing technique offers a great deal of complexity that is not easily nor cheaply replicated by traditional means. I have been in discussions with ARC and hope to have more to present at the next RRS meeting.

125 lbf thrust chamber design, uncooled; prototype for the RRS standard liquid project

[7]
Alastair Martin could not join us at October’s meeting. I was going to have him discuss the current topics of interest at the recent 21st Annual Mars Society Convention held this summer. Alastair is very involved with the Mars Society and the RRS.

Alastair will be at the November RRS meeting so we’ll put this topic on the next agenda.

[8]
New RRS members, Wilbur Owens and Xavier Marshall, are active with the Experimental Aircraft Association, chapter #96, at the Compton Airport in the Los Angeles area. EAA-96 is a like-minded group of enthusiasts centered on experimental aircraft. The EAA-96 has hangar space and a range of machining tools offered to their members.

Experimental Aircraft Association, Spirit of 96

Xavier had mentioned at the last meeting that the EAA would love to host a visit by the RRS. Accepting the EAA’s invitation, the RRS has scheduled a visit to the EAA in Compton on November 3rd at 10:00AM. The EAA will give an hour tour of their facilities and projects. We hope to foster a strong relationship between the EAA and the RRS.

Talk with Xavier Marshall, Wilbur Owens, the RRS president, vice president or secretary for details.

Experimental Aircraft Association (EAA) hangar
1017 W. Alondra Blvd.
Compton, CA, 90220
(310) 612-2751

One of the key points of discussion at this visit will be to discuss how the RRS and EAA can help each other or participant in joint projects. The RRS is interested in using the EAA hangar facilities if they are available. Annual membership at the EAA is $40 to the EAA national society and $40 more to the local chapter at the Compton Airport. As I understand but must confirm, with EAA-96 chapter membership, RRS membership can have access to the machining tools for building rocketry parts for those of us without facilities in our own homes.

Xavier had also mentioned that hangar storage was often very cost-effective which could be a service that the RRS could use as we look to expand our shop capabilities to our membership.

EAA Chapter 96 hangar, Compton Airport

The EAA hangar is just straight east and not very far from our regular meeting location in Gardena at the Ken Nakaoka Community Center just north of Artesia Blvd. (CA-Hwy 91). The address is above.

[9]
Osvaldo’s recent successful design of an alpha parachute recovery system was not able to be covered. We may expand this topic into a fully illustrated RRS.ORG article if we can not get this topic on next month’s agenda. This has been a quiet success and definitely worthy of exhibition to our membership.

[10]
Jerry Fuller of Aerospace Corporation had indicated interest in building and testing a larger subscale prototype of his liquid-infused hybrid motor grain. Aerospace had earlier this year successfully demonstrated a smaller prototype in flight at the RRS MTA. In choosing the next larger design, he has selected a common model rocketry size (98 mm) just under 4-inches which will allow him to use commercially available rocket body parts. Jerry is active with our friends at Rocketry Organization of California (ROC).

At this time, he is still working on the design until resources can be allocated. The RRS has invited him to present his results and the new prototype he has in mind. The RRS is happy to support private groups with a testing area and a community of amateur enthusiasts happy to assist.

[11]
The RRS had discussed having a small group of our membership go out to the next ROC event which is held the 2nd Saturday of the month. Unfortunately, neither I nor Drew were able to go this month. With the Friday night rains falling on the city, it might not bode well for the event at the Lucerne Valley as they must operate on the dry lake bed.

We are looking to coming out to the November ROC event in the Lucerne Valley and hope we can bring other RRS memmbers with us. In particular, some of our members are interested in getting more practical experience through the NAR or Tripoli prefect at ROC. Moreover, some of the RRS membership is seeking experience and support as we acquire letters of recommendation for the California pyro-op licensing in rocketry.

[12]
Saturday seminars have not yet been scheduled, but the RRS is still committed to offering an extended time period for fuller discussions by invited speakers.

[+] RRS member, Jim French, is a speaker of which we would be very excited to have. Jim was a development engineer at the famed Santa Susanna Field Laboratory here in Los Angeles during the development of the reliable and powerful H-1 engine and the injector for the massive F-1 engine. Later, he worked at TRW on the reliable, hypergolic fueled, Apollo Descent engine at TRW at their San Juan Capistrano testing site (now defunct). His book, “Firing a Rocket Engine” is available on Amazon and it is a great read.

Amazon.com – James A. French, Firing a Rocket Engine

[+] Reaction Research Society founder, George James, is another speaker we have been wanting to have. His founding work with his other organization, the Rocket Research Institute (RRI) was a great topic he covered only briefly at the 75th anniversary symposium in April.

[+] Rocketdyne retiree and materials expert, John Halczuk, is another potential speaker on the subject of his extensive research of the V-2 rocket. He gave an excellent talk last year at California State University in Northridge, on history of the V-2’s development and deployment. The V-2 guided many design decisions still used in modern rocketry today in both the United States and particularly in the former Soviet Union.

We were not able to discuss this topic in detail, but more information will be forthcoming, hopefully in the form of an announcement of our first Saturday seminar at the Ken Nakaoka Community Center on a Saturday morning.

[13]
The next RRS symposium date in 2019 will be set soon. Based on the powerful success of the 2018 event, the RRS has decided to further the tradition one more year. We hope to have an even better mixture of universities, private companies and government agencies.

Date to be announced in November, the RRS will hold the 2019 symposium at the Ken Nakaoka Community Center in Gardena

There was no time to formally raise the subject, but it was decided by the council members present at the October meeting that the 2019 RRS symposium date will be formally set by an offline discussion and the date officially announced at the next RRS meeting on November 9, 2018.

[IN CLOSING]
The next meeting of the RRS will be November 9th at the Ken Nakaoka Community Center in Gardena.

We will most certainly discuss the results of the MTA launch event scheduled for Saturday, October 27, 2018. I will build the agenda starting at the end of the month. Please contact the RRS secretary for ideas and information on meeting topics.

secretary@rrs.org

As per our constitution, the RRS will hold its annual nominations of officers for the next calendar year 2019 at the November 9, 2018 meeting. Voting by the administrative membership will take place thereafter and managed by our election chairman. Results will be announced at the next meeting on December 14, 2018.

Thank you for reading.

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