December 2018 meeting

The Reaction Research Society (RRS) held its final monthly meeting of our 75th anniversary year, 2018, on our usual 2nd Friday, December 14th.

We were glad to be visited by Waldo Stakes, Curator of the Saxon Museum in Boron, California, and well-known rocket car maker. Wilbur Owens was kind enough to bring Waldo to the meeting.

Wilbur Owens and Waldo Stakes at the December 2018 RRS meeting in Gardena, newly elected RRS treasurer, Chris Lujan looks on

The agenda for December was kept short as the RRS wanted to take some time to celebrate our accomplishments this year.

After coming to order and the reading of the treasury report, we began the shortened agenda.

[1]
The results of the elections were announced by email from our election chairman, Larry Hoffing, who could not attend. The full slate of officer candidates were voted unanimously with no write-in’s.

The RRS officers for 2019 are as follows:

President – Osvaldo Tarditti
Vice President – Frank Miuccio
Secretary – Dave Nordling
Treasurer – Chris Lujan

We thank our appointed election chairman, Larry, for his service.

The newly elected officers will start their new terms at the beginning of the calendar year. All of our appointed positions at the RRS remain the same as the executive council has voted to retain them. We are thankful to all of our new and continuing membership for making this an important milestone year for the society.

[2]
The next topic was to discuss the UCLA hot fire event at the MTA in November. Osvaldo was very impressed with the UCLA team in how well they communicated and their preparation for a safe hot-fire test. Despite having an earlier setback, they recovered to have a hot-fire in the early night hours that gave them valuable data for their next design iteration. The RRS is glad to support university groups with our testing site. It is great when everyone puts safety and organization first.

Osvaldo reads off the list of events we conducted at the RRS over this anniversary year, 2018; Michael Lunny looks on

The RRS has had other university groups express interest in using our Mojave Test Area (MTA). To any groups wanting to use the RRS MTA, please contact the RRS president by email.

president@rrs.org

We also appreciate each group filling out our RRS standard record form to help explain the basics of what they would like to accomplish. The standard record form can be found under “Forms” on the RRS website.

[3]
The last of the scheduled agenda topics was the announcement of the official date of the 2019 RRS symposium. The symposium will be held on Saturday, April 27, 2019, at the Ken Nakaoka Community Center in Gardena. As before, we will have entire first floor and outdoor courtyard.

The 2019 RRS symposium will be held on Saturday, April 27, 2019

The RRS has had great success in getting a range of speakers from industry, academia and government agencies. We plan to invite the Navy China Lake, Air Force Space and Missile Center, NASA Goddard Spaceflight Center, Northrop Grumman, Relativity and the Additive Rocket Corporation just to name a few, as well as several of our local and regional university rocketry groups such as UCLA, USC, Cal Poly Pomona, CSULB and LMU just to name a few. In the new year as invitations go out and we get confirmation, we will update our agenda for the April symposium. We hope to have an even larger turnout both on our stage, at the exhibition and of course our public audience.

The RRS will be holding a 2-hour panel session as the final event in our speaker series. The RRS is working on building this panel from a good cross-section of industry, government and academia to look at the state of affairs in space today and looking ahead to what may come next as the industry expands.

To those who stayed to the end last year, we were provided a rare treat by former member Bill Claybaugh as he presented his assessment of the current aerospace industry. We would strongly encourage everyone to plan to stay the full day as we will be bringing out more special things as the day goes on.

[9]
This topic was on the original agenda, but we thought we wouldn’t have time. RRS member, Alastair Martin, through his company, Production Tribe, is starting a pod-cast called Rocket Talk Radio. RRS director of research, Richard Garcia, and the RRS secretary, Dave Nordling, have agreed to be the first guests on this pod-cast that will talk about current topics in space and rocketry. As the first few podcasts are made, he’ll look to have other guests, to talk for an hour over a range of questions posed by Alastair and the participating audience.

[X1]
Osvaldo went over the long list of events we held at the RRS starting with the Aerospace Corporation launch test of their prototype liquid-hybrid rocket motor, the three launch events we held through the LAPD Community Safety Partnership (CSP) program where we were able to engage 112 kids in the at-risk communities of Watts in Los Angeles. Both USC and UCLA had a lot of success in their respective rocket programs.

Although USC did have a major setback in their Traveller III flight, they are well positioned for a very successful flight on their long journey to be the first university group to break the von Karman line into space with their boosted dart. The RRS is glad to be recurring partner with USC by assisting with their ground testing needs.

UCLA has also had a successful year with their liquid rocket programs and the RRS is glad to continue our support.

New RRS member, Dmitri Timohovich, and myself journeyed out to the MTA on December 2 for a site improvement project to mount the new road sign we had made. As I was feeling very under the weather on that afternoon, Dmitri did a stellar job in helping the society put a visible marker at our big iron gate leading the way into the RRS Mojave Test Area (MTA). The RRS thanks Dmitri for his hard work for the society.

Dmitri Timohovich makes short work of digging post holes with his motorized auger machine.

The new RRS sign at the first iron gate to the Mojave Test Area ready to greet the next visitors

[X2]
RRS member, Jack Oswald, presented his current progress with his large solid motor building project. His team have been working hard this year having some successes and failures, but always learning. His new ballistic evaluation motor design will correct some of the prior deficiencies in the earlier design and is expected to produce high quality results that should finalize his motor design. Jack and his team from the former Chaminade rocketry group have made a lot of progress and have also helped me with my smaller BEM design. Based on our conversation at the December meeting, I think I will have to re-visit some of my assumptions. Many thanks to Jack and his team’s hard work in supporting the society with their ambitious goals.

[X3]
RRS director of research, Richard Garcia, was not able to attend the December meeting, but he did provide a progress update for the RRS standard liquid project. His injector and chamber design is nearly finished and seems to have all the right features to proceed with build. The injector design is based on a previous design used by the RRS in past liquid rocket projects. He is also re-using his ablative chamber liner feature for this smaller 125-lbf LOX-ethanol engine design. His analytical model of the propellant blowdown system seem to anchor his predictions for what will hopefully be a successful hot fire test in this coming new year, 2019. The RRS is working hard to anchor a reliable and simple to build liquid rocket engine system that university groups can use for liquid rocket competitions in the future without having to start completely from scratch. We will provide updates as this project advances.

[X4]
Richard also brought up the idea of building a rocket sculpture to the right of our big iron gate at the MTA. The society welcomed the idea and we hope to bring this concept to life sometime very soon.

Richard Garcia’s rocket sculpture concept; soon to be seen at the RRS MTA

[X5]
Lastly, Frank was presented with a Community Service award by the Los Angeles Women Police Officers and Associates (LAWPOA) to honor the continuing work of the Reaction Research Society with the LAPD CSP. It is with great pleasure that the RRS accepts this recognition and reaffirms our commitment to this strong program that has done a lot of good for the young minds we hope to inspire.

Bill Janczewski holds up the LAWPOA Community Service award presented to the Reaction Research Society; I think I caught Frank a little off-guard in this photo? He was very pleased.

Our next monthly meeting will be on Friday, January 11, 2019. For an update on our intended agenda for each meeting, check the RRS.ORG website under the “Forum” section.

We look forward to starting the new year with preparations for the 2019 symposium and we will need our full membership to help make this event an even greater success.

Also, the RRS is talking about holding one of our monthly meetings at the Tomorrow’s Museum at the Compton Airport. Also, Jack Oswald has been working on getting tours of The Boring Company in Hawthorne and the Point Mugu Naval Base sometime in the new year.

The RRS wishes everyone happy holidays and a happy new year.

November 2018 meeting

The RRS held our monthly meeting on Friday, November 9, 2018 at the Ken Nakaoka Community Center in Gardena. After coming to order and the reading of the treasury report, we discussed the agenda topics for this month. We were happy to be joined by new RRS member, Mike Albert.

[1]
Results of the RRS educational event at Weigand Elementary School with the LAPD CSP program was very positive. The launch event at the MTA had an excellent turnout, good demonstrations and ten alphas flown. We are becoming more effective in our execution at launch day, but there are still opportunities to improve the speed of operations while keeping our focus firmly on safety.

RRS president, Osvaldo Tarditti, teaches the kids at Weigand Elementary School

The weather in late October was ideal and we were able to enjoy the low winds and cool weather. With the low winds, the impact of all alphas were able to be heard and the timing by the kids showed the flight times to be very consistent. Many thanks to Osvaldo and Michael Lunny for doing a great job in packing them for what looked to be very good results.

the kids of Weigand Elementary School at the RRS MTA on 10/27/2018

[2]
Frank is in the process of coordinating the next RRS educational event with LAPD to be a school affiliated with the Imperial Courts housing project which should begin in January 2019 sometime around the Martin Luther King holiday. The school will be announced soon once the details are finalized. The launch event will likely take place in March 2019.

Michael Lunny (back table); Mike Albert (left) and Frank Miuccio (right)

[3]
Results of Jack’s ballistic evaluation motor (BEM) testing were discussed. Jack and his team were not able to attend the meeting, likely due to the California wildfires in his area on that night. The testing rig had a few flaws and a missing part. It was unclear if any useful data came from the one test. Osvaldo is working with Jack on improvements to his BEM. A deeper discussion of Jack’s BEM will hopefully come at the next meeting.

Jack Oswald’s BEM tied to a stake in the dry lake bed for stability; undergoing preparations for 10/27/2018 testing

[4]
Results from the horizontal thrust stand testing were discussed. Despite the problems with the foundation slab sliding with the firing of the micrograin alpha rocket, the load cell did record data which partially confirmed the impulse bit measurements from the past. Many people enjoyed watching the footage, but in all seriousness, an appropriate mounting foundation needs to be made to continue tests.

Matteo Tarditti secures the load cell fixture to the horizontal thrust stand

One proposed solution was to keep the existing shallow slab and drive a long stake into the ground to restrain the slab from moving south as the nozzle exhaust points north when firing. Another solution is to dig away the soil at the site and pour a deeper, rebar reinforced slab with the same 1/2″-13 female anchors. Keeping the slab low near ground level will keep this simple small foundation from preventing road access around the old blockhouse.

example of a buried foundation slab for the horizontal thrust stand

[5]
The Additive Aerospace flyaway railguide was discussed. The device worked well with the micrograin alpha rocket. The fit was good and the camera footage from different angles showed the alpha in the railguide rode the full length of the rail flying very straight. The flyaway railguide did not survive its maiden voyage, most likely due to impact from the fall back to the ground. Also, there is a concern that using the micrograin rocket on the aluminum 8020 rail would eventually jam the rails with the zinc-suifide residue that coats the surfaces after each launch.

Flyaway railguide clamped around an RRS alpha

The recovered pieces of the flyaway rail guide. A successful launch but the mechanism didn’t survive the fall back to the ground

[6]
The RRS needs to finalize the 2019 symposium date very soon. Frank and others consulted the local calendars of relevant organizations and schools and we have arrived at two possible dates in April. The announcement for the 2019 RRS symposium will be made very soon as invitations and preparations must begin very soon.

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

[7]
We had a discussion of safety issues and propellant handling protocols during the meeting. The issue is complex and there are different opinions about what the RRS should require of our attendees and membership, but two points that were made clear is that safety is most important and that the RRS will seek to educate our membership about compliance with the applicable laws and best practices from our membership experience.

[8]
The RRS visit to the Experimental Aircraft Association (EAA), Chapter 96, at the Compton Airport on November 3rd was a success. RRS and EAA member, Xavier Marshall, gave Osvaldo and I a good tour of the hangar and their machine shop.

The EAA 96 hangar at the Compton Airport

Inside the EAA 96 hangar, door to the office

The EAA has several airplane projects in work including one by Wilbur Owens. We ate lunch at Wilbur’s hangar and talked about future projects at the RRS including the standard liquid rocket.

Relaxing after lunch in Wilbur’s hangar

Wilbur Owens and Osvaldo Tarditti discuss the RRS standard liquid rocket

The visit concluded with a tour of Tomorrow’s Aeronautical Museum and their rocket laboratory. We visited with some of the students who were working on their rocket project. The RRS was glad to see a lot of enthusiasm for the science we love.

Tomorrow’s Aeronautical Museum at the Compton Airport

The rocket lab inside Tomorrow’s Aeronautical Museum

The EAA membership is quite reasonable at $80/year. Members have access to the facilities at the hangar including the lathe, mill and metal shears useful for both aircraft and rocket structures. For those interested in joining the EAA, contact Xavier Marshall.

[9]
The next order of business was the nomination of officers for the next calendar year by our administrative membership in attendance. The first step was appointing of the election chairman which will be Larry Hoffing. The prior executive council members were nominated to their same posts.

Osvaldo Tarditti, President
Frank Miuccio, Vice President
Dave Nordling, Secretary
Chris Lujan, Treasurer

Larry will email our administrative membership for their votes in the coming weeks. Write-in candidates are allowed. The election ballots will be due a week prior to the next meeting. Results of the election will be announced at the December meeting to be held on Friday, the 14th.

[10]
The RRS may have another launch event at the MTA, but this is dependent on confirmation of the appropriate resources needed to support the event. This will likely take place as soon as next week, or possibly on the Saturday after Thanksgiving. The RRS will post the formal announcement on the “Forum” of this website if the event becomes confirmed.

[X1]
Osvaldo was up in Rosamond and was able to take a short trip to the MTA to extract more of the rockets he could find with his ratcheting extractor tool.

A pile of alphas extracted from downrange at the MTA

In addition to the 15 alphas he was able to bring back for refurbished parts, he found the beta rocket that UCLA had launched.

UCLA’s beta rocket recovered from the desert floor

other parts of the beta rocket were able to be extracted including the beta coupler and a fragment of the red plastic nosecone

This beta rocket had an altimeter payload encased in a vented metal shell. Unfortunately, the Jolly Logic bluetooth solid-state device might have survived the crushing impact but the corrosion from possible rainwater intrusion after being planted in the desert dry lake bed sand for over a year proved to be fatal.

Payload case built into the beta rocket’s payload interior; note how the holes were crushed

Chris Lujan is inspecting the device, but it is very unlikely that any data will be recoverable from the chip. It is a shame as getting direct measurements of a beta flight would be great data to have. I guess we’ll have to try again?

Remains of the Jolly Logic altimeter chip, battery still attached

[X2]

At the end of the meeting, I gave a brief overview of a second design for the RRS standard liquid rocket. The system is smaller than Richard’s initial 1000-lbf design and will use ethanol/LOX as propellants similar to prior RRS designs. One of the key features is the custom-built aluminum tanks to be made from common piping sizes and head designs made from aluminum round stock on a lathe. In the last few minutes, I was only able to provide a cursory outline of the project which will be discussed in further details at subsequent meetings. I have identified a few of the key parts including high pressure solenoid valves, aluminum tubing, AN fittings and a common composite overwrapped pressurant vessel commonly used in paintball sports.

simple schematic of a blowdown rocket system, three tank arrangement

[IN CLOSING}

Wilbur and Xavier mentioned that the EAA is open to having the RRS use their office for one of our monthly meetings in the future. Given how close the Compton Airport is to the Ken Nakaoka Community Center in Gardena, this is quite practical. The RRS will make the announcement soon if one of our meetings in early 2019 will be at the EAA 96 hangar.

If there is anything here that needs correcting, please contact the RRS secretary.
The next RRS meeting will be Friday, December 14th, 2018.

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.