Tag Archives: Additive Aerospace

November 2018 meeting

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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

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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 xanax 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 Clomid 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.

August 2018 meeting

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The Reaction Research Society (RRS) held it’s monthly meeting on August 10, 2018 at the Ken Nakaoka Community Center. We were very well attended with four new people including returning member, Jim French. I was unable to attend the meeting, but other council members gave me their notes.

The RRS meeting got a late start at 8:00pm. (Our starting time is supposed to be 7:30pm.) The agenda items were not covered in order, but the list of topics to be covered were as follows:

[1]
This was to be a discussion of the 2018-07-21 launch event that the RRS held at the MTA with LAPD CSP and the student group at Watts. The event was successful with both the student alpha launches and a few RRS member alphas with payloads. The event was summarized in a previous article. A few things could have been done better which will make future events go more smoothly.

[+] A single, simpler briefing to the kids would have been more effective. The kids in the student classes do pay attention at the events (which is great) but the RRS is giving a lot of redundant information and a more concise presentation delivered by only the pyro-op will be far better than having three people talking at the same time.

[+] Also, every person conducting a launch or hot-firing at the MTA must submit a detailed proposal to the pyro-op for review at least a week in advance and gain the RRS and pyro-op’s approval PRIOR to coming to the event. The RRS used to be even more stringent on this requirement. The use of the RRS standard record form is required to be filled out by the experimenter for review by the pyro-op. The RRS requires advance preparation and there is no reason why this can not be done by all participants.

In recent times, our pyro-ops have been very casual about this requirement and have been kind enough to review things on the spot, but this was always at the pyro-op’s discretion. The pyro-op is the single and solo authority for what is and isn’t done at the launch event. The pyro-op should be the most informed individual about what is going to be attempted at the MTA.

The RRS has a Standard Record Form available on this website under the Membership tab of the Homepage and under the subheading of Forms. This downloadable document gives members a basic framework for the detailed information they must provide to the pyro-op describing their project and its goals. The RRS encourages members to present their proposed projects at the meetings and be very detailed in any reports submitted to the pyro-op and RRS president. The RRS wishes to keep good records to benefit the society and future projects.

RRS – Membership / Forms / Standard Record Form

[+] In future events where we have the student launch event conducted first, we should not plan nor conduct any events before the student launch. Getting back to an earlier point, having launch and hot-fire events declared, reviewed and scheduled days in advance will help make RRS events go more smoothly and safely. Years of experience at the MTA has shown that tasks ALWAYS take longer than planned and too much waiting can make coordination of large groups unnecessarily difficult. Therefore, having our coordinated events go off first without distractions from other planned activities will make it easier for our pyro-ops to conduct their duties and make our participants be more organized in their projects.

[+] The extreme heat of mid-July made it very difficult to conduct operations but having the motorized cart to shuttle the pyro-ops to and from the launch site made a critical difference. Bringing ice in the summer is a necessity. Having everyone well prepared for the hot weather continues to be the best advice.

[2]
Chris Kobel who is a member of Rocketry Organization of California (ROC) shared some advice for pyrotechnic operators (pyro-op). Chris has been a pyro-op for over 10 years and is pretty active with amateur rocketry. Safety was the primary emphasis of his presentation. He also mentioned a key point of contact at the Office of the State Fire Marshall (OSFM) of California, Tom Campbell. Mr. Campbell is very important authority at the California State Fire Marshall’s office who can answer important questions. Chris and the other pyro-op members at ROC were also willing to counsel RRS members interested in becoming pyro-op’s.

The RRS was glad to have Chris give our membership a wealth of information. We look forward to working more with Chris and ROC in the near future as the RRS is expanding our roster of pyro-ops for our growing events.

[3]
Osvaldo’s flight telemetry from his alpha flight on 2018-07-21 was briefly mentioned at the meeting. It was good that the flight was successful that data was taken. Given the time constraints, he’ll give more details at the next month’s meeting.

[4]
Progress on the RRS alpha parachute systems and future attempts was to be detailed by both Osvaldo and Larry who each attempted a unique recovery system built into the small confines of the alpha payload tube. Again, insufficient time was available at this meeting and this event can move to next month.

[5]
Sam Austin gave a presentation of MIT’s solid rocket launch and his upcoming liquid rocket hot-fire. Sam is here in Los Angeles for the summer on his internship, but managed to find time to launch his rocket from the FAR site on the same day the RRS held our launch event on 2018-07-21. The MIT team’s custom-built solid rocket motor (O4000) made from scratch reached an altitude of 33,132 feet as confirmed by dual altimeters. The vehicle weighed 121 lbm at liftoff and reached a peak velocity of Mach 1.8.

MIT’s rocket launch from FAR on 2018-07-21

MIT team poses with their rocket, 2018-07-21

Sam described a rough order of operations for their solid rocket grain making process and detailed their recovery. The rocket touched down safely 2 miles away and was fully recovered. The MIT team was elated and attributes their successful launch to careful design, many hours of testing that went into every component. The RRS is happy for MIT’s success and hopes they will test at the MTA with their next rocket.

[6]
There will be a liquid rocket hot fire testing on August 18th at both the Friends of Amateur Rocketry (FAR) site and the RRS MTA. Sam Austin has been working on his liquid rocket motor to test at FAR, next door to the RRS MTA site. Richard Garcia has built a small liquid motor for what could become the RRS standard liquid rocket design. Our two members have agreed to share resources and the hot fire events will take place on 2018-08-18.

Both projects will use a nitrogen K-bottle as their pressurization source and will share a liquid oxygen dewar to provide the oxidizer to both of their engines. Richard’s and Sam’s liquid rocket motors will use kerosene as a fuel. Richard’s design is a 1000-lbf thrust design with an assumed chamber pressure of 300 psig.

Sam and Richard have put a lot of work into these projects and we hope they have success. I plan to go out there to help document the event for a new posting to come shortly after.

[7]
The meeting was to discuss upcoming RRS launch events including the next one with LAPD. Frank has said that the next event with the LAPD CSP will be with the Boys and Girls Club. LAPD CSP is also working on setting up another school group in Watts for an RRS event. Specific dates were not yet set, but that information will be coming soon. We will post announcements of forthcoming launch events in the “Forum” section of this webpage.

[8]
RRS Instagram and YouTube account guidelines have been generated by RRS treasurer, Chris Lujan, and are now being reviewed by the RRS executive council. The idea of creating an RRS media manager position was proposed and accepted by the council. The RRS is considering offering this new position to RRS members, Bill Janczewski and Alastair Martin, who both have put forth a great deal of excellent work for the society. The RRS executive council will vote soon to better our social media presence to help our outreach efforts and give our followers a better view into the society.

Richard Garcia shared access information with the executive council on the existing social media accounts that the RRS has including Facebook and YouTube.

The RRS executive council now has access to Instagram and will be sharing photos from events more easily and quickly with our public audience. I have already begun to load photos I’ve had from recent events. More of the RRS will be posting to Instagram very soon.

Subjects not on the agenda included:

[BONUS 1]
The RRS will start to hold special Saturday morning seminars for special topics that can be covered in more depth outside of our monthly meeting. These bi-monthly sessions will take some work to coordinate, but should allow more of our membership to enjoy the quality of talks that we have been privileged to enjoy. Jim French agreed to give the first of the RRS Saturday seminars at a date to be determined very soon. Jim was a member of the RRS 25 years ago and we’re happy he’s come back to join us.

book by RRS member, Jim French

James R. “Jim” French also has the distinction of being a rocket engineer for over 60 years and worked at TRW on the Apollo program. He wrote a book about his experiences called “Firing a Rocket”. This first RRS Saturday seminar will be a great presentation to start this series. The date will be announced soon.

[BONUS 2]
I have been able to get the top and bottom plates made for the RRS ballistic evaluation motor (BEM) which will be a key part of the SuperDosa project and the RRS having the ability to take accurate burn rate measurements at the MTA for future motors. I am thankful to Matt Moffitt of CNC Specialty Machining in Huntington Beach. I hope to have the cylinder piece in the RRS BEM machined soon. This will likely require lathe work. Osvaldo is also looking into getting this part made. It is my hope the RRS BEM can be completed by the next quarterly update of the SuperDosa project in October 2018.

Top and bottom plates for the RRS BEM just back from the mill.

I have heard that Jack Oswald is trying to get into testing his large solid motor with an improved design. The RRS may have more to present next month on this subject.

[BONUS 3]
I wanted to bring a special device I bought from Additive Aerospace called a fly-away rail guide. I was introduced to this device by David Reese of ROC. Although the RRS has a very effective box-type rail launcher at the MTA site which will remain our standard technique, I decided to attempt a new method of launching an alpha just to get a longer guided path on launch.

Additive Aerospace – fly-away rail guides

This device allows a rocket to be fired from a extruded aluminum rail launcher such as the one we have at the RRS MTA, but without having to permanently attach the round launch buttons to the rocket itself. A spring-loaded clampshell piece goes around the rocket with a launch button on either side such that the clamp is closed when the rocket is on the rail. As the rocket takes off, the fly-away rail guide goes with the rocket along the rail launcher until the buttons clear the rail and swing open releasing it from the rocket as it speeds away.

Fly-away rail guide from Additive Aerospace; custom-built for an RRS standard alpha rocket, shown in the open position.

These devices are intended for common model rockets of the standard metric sizes (38mm, 54mm, 76mm, 98mm). I had this rail guide customized to fit an RRS standard alpha rocket which is slightly smaller than the 38mm size at 1.25 inches in diameter. I hope to demonstrate the fly-away rail guide device with a loaded RRS alpha from the 12-foot rail launcher at the RRS at the next event. I will relay my findings to the society and back to Additive Aerospace who is very interested to see how their design can work with the RRS micrograin rockets.

[IN CLOSING}

Meeting adjourned at 9:16pm which isn’t too bad. Our hosts at the Ken Nakaoka Community Center continue to graciously allow us to finish up despite the center’s closing at 9:00pm on Fridays. The RRS should seek to better finish on time as the staff at the center need to go home.

The next meeting of the RRS will be held on September 14, 2018.

For questions, contact the RRS treasurer, Chris Lujan.
treasurer@rrs.org