MTA launch event, 2018-07-21

The Reaction Research Society (RRS) held a launch event at our private Mojave Test Area (MTA) on Saturday, July 21, 2018. As I came into the site in the morning, I snapped a picture our front gate and the rough location which will be the site of our new sign to arrive very soon.

Follow that car. Turn left to go to the RRS.

Jim Gross was our pyro-op for the event. Many of us arrived early so Jim and the rest of the RRS had time to review the projects we wanted to hot-fire and fly if possible that day. Also, it was new members’, Michael Lunny and Bill Behenna’s first trip to the MTA. I think there is no better way to sell our membership on the benefits of the RRS than your first trip to the MTA. It worked for me!

Jim Gross, our pyro-op for the day

We were glad to host another group of students from the Watts area schools with the support of the Los Angeles Police Department’s (LAPD) Community Safety Partnership (CSP). This has become known as the “Rockets in the Projects” program.

LAPD CSP on Facebook

It was a challenge to hold this event in July in the Mojave desert, but the kids and staff seemed to withstand the 100-degree heat quite well with lots of water and bringing ice. We gave our safety briefing to everyone and explained the do’s and don’t’s for the event. RRS member, Matt Tarditti, was there helping with getting people shuttled around to the places necessary including moving our pyro-op, Jim, and his apprentice, (me) Dave Nordling, back and forth between the bunker and the alpha launch rails. Every step adds up in the heat and it’s wise to work as efficiently as you can. The heat ultimately got to me and I had to take a pause into the air conditioning of my truck. Despite my best efforts in hydration, the Mojave summer was still overwhelming. It is a feeling that many RRS members know all too well at some point in their time with the society at the MTA.

Matt was kind of enough to continue to assist Jim to complete the launch series with the alphas. Even, Jim Gross, who has been a resident of the high desert for many years, was having a tough time in the high temperatures and very low winds of that day. We had extremely low winds which made for great rocket launching weather, however with the building clouds above holding in a lot of the heat of the day, it was a real challenge for everyone to fight the stifling heat. The RRS conducts launch and test events at the MTA year-round, but some months are harder than others.

Matt Tarditti and Jim Gross under the hot July sun at the MTA

The LAPD CSP team does a great job in preparing these kids in the weeks ahead before this event. Often, this is many of the kids’ first trip into the Mojave desert. The stark beauty of the landscape hides the subtle dangers of snakes, spiders and the ever-present risk of heat stroke (even at 10:00 AM!). The RRS educational program is both fun and informative and through preparation everyone can make things safe. The kids were quite ready for the final event in the RRS educational program which is seeing their painted and assembled RRS standard alpha rockets take flight.

Michael Lunny, Frank Miuccio and Larry Hoffing stand among the students during the safety briefing at the George Dosa building

Our first goal of the event was to get the students’ rockets in the air so that those less experienced in the desert heat can go on home once the last one was complete. We had seven standard alphas to be launched, all painted by the students as their way to personalize their team’s flight. As always, the RRS reminds our classes that painting the bodies is nice, but since they return to the ground without a parachute, painting the fins in a bright and observable color matters the most when trying to find them on the desert floor. You’ll only have the tail fins sticking out of the ground when you find your rocket.

Seven alphas in the rack from Watts, plus Larry’s customized alpha with the wires sticking out of the payload tube

The kids paid careful attention to the time of flight which gives some data as to how well packed the alphas were. Two stopwatch measurements were made on each of the seven alpha flights. Impact was not heard on the seventh flight, so no data was taken. The results are somewhat consistent between the two readings and ranged between 36 and 39 seconds.

Time of flight measurements on six of the seven alphas flown on 07-21-2018

Ideal time of flight for an RRS standard alpha is thought to be between 35 and 42 seconds. This would indicate that Osvaldo’s rapid micrograin loading system is doing well to properly pack the propellant leading to good results.

Still shot from Michael Lunny’s video of the RRS standard alpha taking off

After the sequential launch of all seven alphas, it was unanimously decided not to let the kids hunt for their rockets downrange. The LAPD CSP team and the Watts kids went home after taking a picture under our arched sign. RRS member, Michael Lunny, shot a great video of one of the alpha launches from the bunker. I hope to get it posted to the RRS YouTube channel. We have a few micrograin rocket flights on YouTube, but we hope to add more content there soon. You’ll notice our name is not fully spelled out due to the old character limit when the account was made.

ReactionResearchSoc

Reaction Research Society on YouTube

After the Rockets in the Projects, this left the rest of the RRS membership to attempt the other projects we had ready for this launch day.

Richard Garcia brought his home-built rocket that is adapted for the sugar-KNO3 motor he tested at the 2018-06-02 event. He made three motors, one as a simple end-burner, the other two were cored. The plan was to fire conduct a static firing or two with his test motors and if all looked good fly the third motor in the rocket from the RRS rail launcher. “Rocket candy” as it is also called in amateur rocketry has been getting more popular at the RRS.

Richard Garcia stands in the assembly area by his golden rocket built for his custom sugar motor

Richard’s end-burner grain, 2018-07-21

Richard’s nozzle for his custom sugar motor

Richard’s two cored grains, sugar-KNO3 motors, 2018-07-21

Richard brought back his vertical static fire stand that bolts to the larger RRS frame. Although his thrust stand is not outfitted with a load cell (yet), it does give him the opportunity to safely secure his test motors and visually compare the results and time the burns.

Richard Garcia’s sugar motor held down to his vertical thrust stand for static fire

Larry Hoffing made a parachute system in his RRS standard alpha. His system was a little different from Osvaldo’s as he required a second firing line to light a delayed fuse for the parachute deployment system he put in. His son, Max, was there to help get things ready for flight as we included Larry and Osvaldo’s alphas into the launch sequence. Larry’s goal was to explore an older method of timing the deployment of his parachute by use of cannon fuse.

Larry’s alpha payload system being made ready for flight, 2018-07-21

Also, Larry had attached a signalling whistle on one of the fins. The ancient Chinese used to mount whistles on their rockets of war to strike fear in the hearts of their enemies as the rockets would scream to their target. It was Larry’s intent to add the element of sound not only for an impressive screeching launch off the rails, but also for better tracking of the rocket’s final descent to the ground. Although having a single whistle mounted to just one fin will impart a spin to the alpha, the flight will still be stable as proven on similar alpha flights. In the recent past, we have had success flying a larger, single keychain camera on the outside of a single fin while maintaining good flight stability despite the nauseating rapid spin seen in the footage from these externally mounted cameras.

Larry’s alpha with a whistle mechanically fastened to a single fin, 2018-07-21

Osvaldo inspects Larry’s alpha rocket in the launch rails with the second firing line connected for the fused payload timer

Unfortunately, Larry’s alpha had a problem at launch with the failure to light the micrograin rocket. Also, with this delay it was apparent that the parachute payload deployed way too early. The goal was to fire at 20 seconds in the flight and the fuse seemed to go at only 2 seconds popping the payload tube while the rocket stayed on the alpha rack. The two systems had to fire at nearly the same time but one system failed entirely and other went off too early.

After exploring all other failure modes with the firing circuit and procedures, it was confirmed that it was a bad electric match with a break in the wire. This was the first time I’ve seen an electric match fail in the three years I’ve been with the RRS, but it has been known to happen. With Larry’s whole payload system requiring repackaging, it was decided for expediency, just to remove Larry’s rocket from the launch rails, remove the nozzle and dump the micrograin propellant for a safe disposal burn on the ground. Larry will be able to re-use his alpha hardware, but it will have to wait for next launch.

Next was Osvaldo’s red colored alpha with his alpha with a parachute system built in it. Osvaldo made some minor improvements to the circuitry and this was to be his second flight. He also had a commercial telemetry package within his payload section.

Osvaldo’s red alpha with the breakwire switch to start the timer and the pull pin to arm the battery before walking away to the bunker to fire

Osvaldo’s alpha parachute system, break-wire secured to launch rail starts the internal timer

The first flight of his original parachute design for the alpha on 2018-06-02 was a complete success. Despite some slight overheating of the parachute from the black powder deployment charge on the initial flight, the rocket still coasted down very gently such that it laid neatly on the ground and a shovel wasn’t necessary for recovery.

The flight of Osvaldo’s second alpha was similarly successful in that the break-wire system and deployment mechanism operated properly, but the parachute itself failed to unfold due to tangling. The rocket’s descent even with the folded parachute was able to be spotted and Osvaldo recovered all pieces of his second flight.

Osvaldo inspects the second iteration of his alpha parachute system, 2018-07-21

Also, as an added bonus, Osvaldo was able to fit a commercial telemetry package to measure the flight acceleration. As the whole package survived in tact, it will be very interesting what the device was able to measure from within the tight confines of alpha payload tube near the nose. I hope he can present his results from the flight at the next meeting.

Osvaldo’s data package survives the flight, a little singed, and despite a folded parachute

There has been a lot of great progress in parachutes for the RRS standard alpha recently. Both Larry and Osvaldo have made great progress. With the persistent efforts of our RRS membership, I think its reasonable to expect that we could offer a standard alpha parachute package for our future events once we demonstrate a series of successful flights, settle on the design and figure the added cost.

Richard Garcia’s project having two successful static firings gave him confidence to try to mount and fly the third sugar motor. After having some initial integration problems and a rail button coming off, he was able to get his golden rocket ready for a launch on the rail launcher.

The rail launcher at the MTA is a great asset to the society. It has been used on several projects with good success, but it is a very heavy and sturdy device that requires two or three people to assemble and make ready. Also, the pin system that connects the rail to the stand fits very snugly and sometimes requires a lot of elbow grease and persuasion (perhaps with a rubber mallet) to get the right alignment of the holes. Despite the high heat, we managed to get things ready for Richard’s flight.

Rail piece with 12-foot, 80-20, 1515 aluminum rail

Launch rail base

Launch rail system ready to receive the rocket

Underslung launch rail system at the RRS MTA, assembled and ready for Richard’s flight, 2018-07-21

80-20 aluminum 1515 sized rail (1.5-inch) used as the guide for the launcher

Richard checks the manual for the telemetry package that he armed for flight.

Richard’s flight was on one hand a little underwhelming as his sugar motor did not produce a great deal of impulse, but it did manage to propel itself up and get clear of the launch rail before neatly turning back to the ground in a low-speed, but very steady and stable flight. Although his rocket only made it 50 feet downrange, it can be seen in the flight video that his rocket was stable throughout the whole low speed which is a testament to Richard’s good construction of a very aerodynamic and well-balanced vehicle.

The sugar motor doesn’t offer much impulse as it burns out shortly after clearing the launch rail

The rocket gently pitches over after burnout heading for the ground not very far downrange (the last good frame I have from my camera-phone)

After a perfect arc at its low apogee, the rocket turned back to the ground and landed almost perfectly on its nose. Despite the rough landing, the nosecone wasn’t damaged and many parts of the vehicle were similarly undamaged.

A very short, but extremely stable flight off the rails for Richard’s golden rocket with a custom sugar motor

Richard safes his payload system as he inspects the recovered rocket.

Richard will be working on increasing the impulse from his motor, but he can be very confident in his vehicle design. With a little rework on some of the parts, I think he should have a very impressive flight at the next launch event.

Osvaldo has put a lot of work into the horizontal thrust stand that I started. To be able to static fire an alpha rocket to measure the impulse, we have to accomplish two more things.

RRS horizontal thrust stand in need of an extension piece to stabilize an alpha for static fire

The first is to get better mechanical support for an RRS standard alpha to prevent sideways motions or “wagging” during firing. The stout, welded frame of the horizontal thrust stand fits just fine to the concrete slab foundation and is very secure, but the 3-foot length of an alpha could create quite a wicked angular load on the load cell. After Osvaldo and I had discussed a few design concepts, Osvaldo brought his design to the MTA. Given the time constraints of the launch events that came before and the stifling heat, we had no time to attempt a fit check of an alpha rocket in the thrust stand. The complete assembly will have to be fit checked at the next event. Osvaldo had also noticed that when the long alpha rocket is put into this short stand, the rocket doesn’t align very well with the beam. Some minor adjustments might be necessary to make sure the thrust vector is properly aligned with the axis through the load cell.

RRS horizontal thrust stand extension piece

The second thing is to try to calibrate the load cell to make sure the S-type load cell is still reasonably within its original factory calibration. Osvaldo brought in a home-built frame with a hydraulic jack and pressure gauge which can reasonably approximate a force by the pressure and piston area relationship. We didn’t have time to try this setup, but this device can be demonstrated at home if Osvaldo has time before the August 10th meeting.

hydraulic jack testing rig for verifying the S-type load cell calibration

hydraulic jack-based force tester with high pressure gauge attached

The horizontal thrust stand was not ready for the 2018-07-21 launch event due to a lack of cabling and a hardy computer to manage the data acquisition. Many of us are reluctant to bring our personal laptops to run the data acquisition in the abrasive sandy dry lake environment at the MTA. Chris Lujan at the July meeting talked about using a simple Arduino Raspberry Pi computer as a low-cost alternative to gathering and processing the data. Hopefully, the RRS will get a simple device for this purpose and have it programmed to take data from the load cell as we conduct our hot-fires from this horizontal thrust stand. There still is a lot of work to do in getting the horizontal thrust stand working. With more hard work, the RRS will have this project working soon, hopefully by the next launch event in the fall. We’ll post updates as this project advances.

One final note on the event is that the RRS will be posting a few things on Instagram once the secretary (me) has time to get things started. The RRS is brand new to Instagram so we hope to expand our presence here to better show everyone what we do. At first, the RRS executive council will have access to post photos at the events we attend for the RRS. We hope this presence on Instagram will generate more excitement and participation at events with the RRS.

Follow RRS on Instagram

The RRS will certainly discuss today’s launch event as a whole at the next meeting on Friday, August 10, 2018. There were a lot of great things we tried at the event, but there were also a lot of logistical things we can do better next time. Also, it would be a good time to review some of the material improvements that we ought to make at the MTA to better handle the projects we expect in the near future.

Please join us on August 10th!

July 2018 meeting

The RRS held its monthly meeting on July 13, 2018 at the Ken Nakaoka Community Center in Gardena. We got a late start (7:45pm), but we were very well attended. New member, Wilbur Owens, brought a friend of his from the Compton Aviation Museum. The RRS accepted a new student member, Bill Behenna. We also had two newcomers from Caltech stop by who were interested in joining the society.

Our July 2018 meeting gets started

We welcomed our newcomers and started our meeting with a very full agenda. Frank brought a new air launcher device he built which operates by a hand piston. We didn’t have time to discuss it but Frank is adding more teaching tools to our educational program to show how much fun even simple rocketry can be.

Frank’s hand pump air rocket launcher

We went a little out of order from the agenda, but we managed to cover all topics in this meeting that ran very late.

[1]
The first topic of the agenda was to confirm to everyone that the next launch event at the MTA will be on July 21st. We will host a new group of students completing the RRS educational program. This is another fine group of students from the Watts area and we are grateful to the LAPD CSP program for their continued support of this recurring and successful project. Frank and Larry noted that we will try to get this event started earlier to attempt to avoid the scorching heat of mid-day.

Also, we had a discussion about how to improve the society communications in the wake of a last minute unforeseen change of schedule for a launch event. This was an exceptional case and unlikely to happen again soon, but it did highlight an important aspect of RRS operations which is communicating with our membership. It is very, very important that all active members have their emails with the RRS secretary as the duty to send out the mass email falls to me. There are two ways that the RRS secretary communicates to our active membership:

    (1) the email list for meeting agenda notices

I have been building this email list and maintaining it, but I know that I am missing some interested parties. The communication between our membership is still important. Please be kind to other members and pass on the notices and encourage everyone not receiving their emails to let me know to make the proper inclusions. This is a constant work in progress and I am thankful to those who help make this happen.

    (2) posting of all launch event dates is on the RRS website

I regularly update the launch date information under the “Forum” section of the RRS website under the “Launches” tab. Modifications to the RRS.ORG website were discussed as a means to make a clearer way for anyone to see if we are “GO” or “NO-GO” before the launch event. I’m not sure what Chris Lujan has in mind, but we will discuss this issue further as time goes on. Effective communication to our membership is important. The use of other social media platforms like Twitter or Facebook were suggested, but it is not clear how widely used these platforms are with our membership that spans many generations of technology adoption.

[2]
The second topic from the agenda was my proposal for the RRS to acquire a road sign. This has been approved by the society and the cost is not unreasonable. Placement of a simple sign at the first gate leading into the RRS’s private testing site, the Mojave Test Area (MTA), will make it easier for newcomers to be sure they are going directly to our site adjacent to the Friends of Amateur Rocketry (FAR).

RRS sign at the MTA entrance

The RRS does have a great sign built on top of a metal arch right at the entrance to the MTA built by member, George Garboden, but the society felt a second smaller sign (24 inches tall by 36 inches wide) at the first gate would be another helpful feature to show newcomers the way in.

Proposed road sign for outside the first gate to the RRS MTA

Placement of the sign will be about 10 feet behind the barbed wire fence about 6 feet to the left of our larger metal gate. This should assure good visibility to those reaching this fork in the road.

We had a substantial discussion about the sign content. The results of this discussion are in the sample posted from the website. We also had a substantial discussion about mounting of the sign and the desire to have a solid structure that can withstand years of the gusting winds of the Mojave. The sign quality chosen was of the highest quality to assure a long life under the corrosive effects of Koehn Dry Lake. Richard has suggested that the sign include the RRS logo which I will look into with the vendor. The RRS has given the authority to proceed on this task.

Further to this subject, Richard Garcia has suggested the sign be accompanied by some kind of metal sculpture representing a rocket. This would nicely complement the sign, but this is a topic beyond the original scope of the meeting. In times past, George Dosa had a large metal pipe embedded vertically into the dirt which used to have fins on it like a rocket reaching the end of its ballistic flight. I think the pipe is still there but the fin decorations have been long removed.

[3]
The subject of Saturday seminars was only briefly discussed at the July meeting. In past meetings, the RRS has had special presentations made by invited guests. These are very enjoyable to our membership, but they do often run long and consume a lot of meeting time. To be more effective in our meetings, it was recommended that for lengthy presentations, the society ought to schedule a special meeting for our membership on a Saturday morning at the Ken Nakaoka Community Center in Gardena. This way, those of us with day jobs can come to the center before the heat of the day and enjoy the presentations at our leisure. The RRS has identified several potential candidates for these “Saturday seminars”, but thus far, the first session has yet to be scheduled. We will revisit this topic in later meetings. Our vice-president, Frank Miuccio, will be the point of contact on this topic going forward. Updates on this topic will be posted on this website.

[4]
The RRS director of research, Richard Garcia, discussed his progress with the RRS standard liquid rocket. This has been garnering a lot of enthusiasm as many universities have been pursuing similar goals.

RRS director of research, Richard Garcia, explains his liquid rocket prototype at the 75th anniversary symposium

The RRS has decades of experience in building these powerful but simplified launchers, but in recent times our activity in this area has been slight. Richard has made a lot of the key drawings, but is still working to finalize the dimensions and proceed with construction. The RRS membership at the meeting had the chance to review his current drawings and make suggestions. Richard will proceed with completing the design and drawings and with the RRS support begin with selection of suppliers, machinists and construction.

Richard’s rocket will use the RRS 15×15 rail launcher that we have at the MTA. The 16-foot rail length should be sufficient to guide the rocket to a stable initial flight. Further aerodynamic study will be needed to finalize the design. Preliminary pictures and features of the design will be discussed in future posts.

[5]
The next topic was the subject of pyrotechnic operators and the RRS’s mission to qualify more members as licensed pyro-op’s to expand our ability to conduct events and improve the knowledge of our membership in this important aspect of safety in operations. What we do can be very hazardous, but with the attention to detail and commitment to safety that we have shown over the decades of our history, we are blessed to not have ever had a fatality and very likely to continue this tradition long into the future.

The RRS has identified a few members including myself who are committed to starting the process of becoming a pyro-op with the California State Fire Marshal’s office. The first step is making a request to the Cal State Fire Marshal for their latest package of information which includes a PDF copy of the latest laws and regulations that every pyro-op is expected to know.

California State Fire Marshall rules on fireworks also governs amateur rocketry

In parallel, the RRS is creating a standard package of information for members that include these state provided materials and other resource materials deemed useful by the RRS to properly educate any current or aspiring pyro-op.

The second step in the process is getting five letters of recommendation from licensed pyro-ops of the same class or above the class level you are applying for. The first level of licensing is Rocket Class 3 which is what our new pyro-ops will seek. The final step is paying your exam fees to the state of California, sitting for the exam, passing the exam and getting your license information from the state. It is very important that our membership strive to keep their state license current and not let it lapse. The RRS is indebted to our pyro-ops for making a big part of what we do possible and safe.

Letters of recommendation require a licensed pyro-op to vouch for your abilities to conduct safe operations and a demonstrate sufficient knowledge and competence in all relevant areas for rocketry all in a signed document sent to the state of California. It is not an easy thing to ask of someone who doesn’t know you well. It is not uncommon and very reasonable for many pyro-ops to refuse a request for a letter of recommendation. It is the requester’s sole duty to prove themselves to each licensed pyro-op that they are worthy of their endorsement.

In the past, the RRS had many pyro-ops and by attending MTA events and participating in meetings and other society events, RRS pyro-ops would get to know you and could more easily vouch for your skills to the state. Osvaldo has been successful in securing his letters of recommendation and sending his application to the state. He is now waiting for instructions on when to sit for his examination. This is a process that can take months.

I have also been fortunate to secure letters of recommendation from licensed pyro-ops, but I am still in the process of qualifying in the eyes of other pyro-ops I have asked for their endorsement. It was suggested that the new class of RRS pyro-ops combine our efforts and share our resources. It was also suggested that we ask some licensed pyro-ops to make a presentation at an RRS meeting or special event as a way of educating us in the practical knowledge that they have gained as a pyro-op. Perhaps through these sessions, more of our members can get the letters of recommendation necessary to begin the process.

Dave Nordling assists in the loading of an RRS alpha into the rails under the instruction of pyro-op, Dave Crisalli

It is my intent to encourage the RRS to adopt a more unified approach to gaining this knowledge either by seminar or by apprenticeships that could be offered by other rocketry groups such as Rocketry Organization of California (ROC). I took the action to approach ROC and other amateur rocketry groups about sending a set of our aspiring pyro-op members to a launch event or special training session in the hope to achieve wider endorsement and help build the RRS roster of pyro-ops.

[6]
As required since the start of the SuperDosa project, I presented my quarterly update.

To remind everyone what the SuperDosa project is, it is the society’s desire to retake the amateur rocketry altitude record lost in 2004 to CXST. At a height of 380,576 feet (116 km), this is a daunting challenge, but we have a substantial amount of knowledge and experience from our past members to drawn upon. Many boosted dart designs, similar to the SuperLoki or Viper III, are capable of reaching this altitude range above the von Karman line of 328,083 feet and 4 inches (100 km).

Boosted Dart – Viper IIIa

We have decided to begin a long process to build a boosted dart type of rocket and launch it from Spaceport America or Blackrock to retake the amateur rocketry altitude record by aiming for 400,000 feet (121.92 km). This will take several attempts and perhaps a few different designs, but eventually we will succeed.

For comparison, USC recently set an altitude record for a university built rocket of 144,000 feet (43.89 km).

Some of our newest RRS members just recently fired a full-scale solid motor at the MTA with the aim of reaching 150,000 feet (45.71 km).

The vehicle that succeeds in meeting this challenge and restoring the RRS title will be named after long-time member and a mentor to many in the RRS, George Dosa. George was the first licensed pyro-op in California for rocketry and wrote large portions of the rules governing our hobby. George is still active with the society and we are showing our gratitude by using his name for this project.

SuperDosa-mockup (2)

George Dosa at the 75th RRS symposium in April 2018, third from left

Substantial progress has been made by Larry Hoffing in making sample batches of the RRS standard recipe, although I understand he had to make some deviations to the mixture due to lack of particular chemicals necessary for plasticizing and release from the mold. Addition of accelerants such as iron oxide is not necessarily part of the RRS standard mixture, but it has been used in other mixtures to increase burn rate with good results. The RRS is in the process of re-establishing suppliers for the key materials such as the HTPB binder and the ammonium perchlorate and aluminum powder of different sieve sizes.

Substantial progress has been made with some of our new members and their booster design which was unsuccessfully tested on June 7, 2018 at the MTA. The mixing procedure and some of the equipment necessary for casting larger grains will surely be useful in this sustained effort to build motor of this size. Part of the issue was poor subscale testing to get burn rate data.

The RRS is working on completing a ballistic evaluation motor (BEM) to attain proper propellant curve data which should benefit all society projects using the same solid mixture. I have not had any luck with the getting our top and bottom plate assemblies yet, but I hope my machinist will be available soon to complete all parts well before the next quarterly update.

RRS ballistic evaluation motor design concept

Some of the parts are ready. Richard Garcia was kind enough to turn out the initial set of nozzle pucks of variable throat sizes. I have the fasteners and gasket materials which need to be cut for the seals. The RRS has a 5000 psig pressure transducer and some of the fittings, but we need a short length of clean stainless steel tubing to make the pressure connection. We have a data acquisition unit, but the wiring harnesses needed to be made to route back to the blockhouse.

Chris Lujan has recommended that instead of bringing someone’s personal laptop we get a simple computer like a Raspberry Pi unit to do the data crunching and output the results. The desert environment can be very damaging and it would only take a simple computer to manage the data and output the results. Chris will work on this hardware and software aspect of the data acquisition and processing.

RRS BEM graphite nozzle pucks, courtesy of Richard Garcia

More progress on the SuperDosa progress will be presented in October at the next quarterly report.

[7]
The next topic of discussion was led by Alastair Martin. Alastair is a very active member of the RRS and the Mars Society. He is a filmmaker and producer and brings many talents to the society.

Alastair Martin records elements of Richard Garcia’s rocket candy propellant manufacturing process at the RRS MTA, 4/7/2018

Alastair discussed the necessity of the RRS embracing a larger social media presence. The benefits are that the RRS can reach a wider audience, particularly in the younger demographics. Alastair recommended that the RRS open an Instagram account and do work on improving our Facebook page that is already online. Although there are other social media platforms, it was these two services that he has the most success in his businesses.

The use of Instagram can make the society better able to show the world a glimpse of our activities from a select group of our active membership. Instagram is useful for conveniently and frequently posting photos and short videos and is virtually instantaneous. This nicely complements the website we currently use. The RRS approved the opening of an Instagram account.

Once you have the Instagram smartphone app loaded, you can find us at our Instagram ID which is our full name without spaces:
Reactionresearchsociety

Our society treasurer, Chris Lujan, generated the account and he will be primarily responsible for the RRS Instagram account. The executive council, director of research and events coordinator will be the first members to have permission to post photos to the RRS Instagram feed. The RRS will consider allowing other trusted members to post on our new Instagram account as we go on.

Reaction Research Society on Instagram

The RRS has a Facebook page. I think it is our vice-president Frank Miuccio, that maintains this site. The RRS will strive to post more often on Facebook which is widely used by many people worldwide.

RRS on Facebook

As secretary, I will continue to maintain our world-wide web site, RRS.ORG as our primary means of advertising ourselves and posting updates to activities.

[8]
After some debate and discussion, the RRS has decided to proceed with holding the 2019 RRS symposium in April next year. Although it is a substantial commitment of resources and money by the society, the 2017 and our 75th anniversary symposium were successively larger hits with our public audience. We will strive to improve our symposium based on the lessons we’ve learned and use the momentum of enthusiasm built from two very successful events. However, it was agreed that after the 2019 RRS symposium, the society will not hold another for two years. Our commitment to what will be the 2021 symposium will be pending until the year before.

The 2019 RRS symposium is coming in April.

With this decision, setting the date and starting our long process of contacting industry, academia and government speakers will begin. There will be more discussed on this topic in future meetings. We are excited to confirm another symposium and hope to make this event even better than before.

[9]
The agenda had originally stated that our next launch event at the MTA with LAPD CSP will be Saturday, July 21st. We circled back to this topic reminding everyone that the safety briefing will be conducted at 10:30 AM and the launch event will proceed at 11:00 AM. It is the goal to have all eight of the standard alphas assembled by the students launched before the heat of the noon-day sun rises. We want to encourage our membership and invited guests to this event to arrive very early which for me means leaving Los Angeles at least before 7:00 AM. Dave Crisalli will be our pyro-op for this event and I have volunteered to be his apprentice unless one of our other pyro-ops in training would like to do so.

[10]
I had an agenda item to discuss future events at the MTA including one possible event with a BBC program in the UK. This may occur in October 2018 and discussions are still in work. The RRS will likely hold another educational event with the LAPD CSP in the fall which may be able to coincide. Larry had made contact with the Girl Scouts of Orange County who were seeking the RRS to participate in a regional STEM event. All of these projects will also be discussed further at the next meeting in August 2018 as more information comes in.

[11]
Osvaldo gave our meeting audience a demonstrate of his new method of loading micrograin propellant (without the propellant of course). For some background, the RRS standard alpha is a common platform in our society events. They are particularly common with our educational classes that we hold regularly. Based on the micrograin propellant invented by our founder, George James, this simple mixture of zinc and sulfur powders presents a challenge in loading. The coupler is installed with an O-ring seal at the head end. The 3-foot long, 1.25-inch DOM steel tube with four welded sheet metal fins and holes drilled for installing the nozzle is basically an open tube closed at one end.

alpha bulkhead loaded and bolted in

RRS standard alpha configured for propellant loading; nozzle is installed at the end of loading

The 80% zinc and 20% sulfur by weight propellants are premixed by tumbling and is loaded into the propellant tube by hand. Entrapped air is a frustrating factor in getting a tight packing of the propellant into the tube. As the powder falls to the bottom, the air can not completely get out of the way and empty pockets form. These pockets can be released by simple mechanical tapping or gently bouncing the tube vertically on a wooden block. In the finite volume of the propellant tube, entrapped air is a waste of space that could be filled with the mass of propellant. The loaded weight of the alpha subtracted from the empty weight of the alpha propellant tube at the start is the only real gauge of how well packed the propellant is.

Many methods of compaction and casting of the micrograin propellant to achieve higher densities have been tried over the RRS history. Some of these have had success, most did not. This topic is a long subject which can be researched and summarized in a separate article if there is sufficient interest. For now, only the simple method of manually loading the premixed powder will be discussed.

The common method used today is to pour in the propellant mixture one cup at a time and bounce the bottom of the tube on a wooden beam. Vibration devices do work, but they tend to work too well in that the zinc and sulfur being of different densities start to separate which is very undesirable. This method of one cup at a time is slow, but effective.

a cupful of micrograin propellant drawn from the tumbling mixing drum

traditional loading method that carefully removes trapped air by periodic mechanical tapping is very slow and very messy

When the RRS started to run more launch events with schools, loading a dozen or more propellant tubes started to take a great deal of time including coming to the MTA on the night before. Osvaldo who is the main person doing this loading sought a faster but effective means to loading.

He tried a few experimental practices including drawing a vacuum at the bottom of the tube with a special fitting and using a lowered piston on a string approach, both of which were flawed and not that successful.

His most recent method has proven to be very effective and quick. He gets a length of tiny brass tubing and loosely affixes a round cardboard disk. With this cardboard disk inserted into the mouth of the tube and a proper funnel attached, the full propellant load of the alpha can be loaded directly into the funnel.

Rapid micrograin loading by small brass tube and cardboard disk

By allowing the weight of the full propellant load to lower itself into the tube on top of the cardboard disk, the disk serves as a seal to divert any entrapped air beneath up through the hole in the brass tube. The air below the solid powder mass has a route to escape through the hollow tube up the center. With this technique the whole propellant load can drop into the tube in one motion, leaving the cardboard disk at the bottom. The brass tube easily pulls out from the cardboard disk and out of the propellant tube now loaded with the micrograin propellant.

tube and cardboard disk aligned in the funnel in the mouth of an empty RRS alpha propellant tube

Illustration of rapid method of loading micrograin propellant

This technique eliminates the barrier of the air below trying to move past the falling mass of powder and results in a reasonably dense packing of the propellant all done in one shot.

Osvaldo Tarditti and his rapid method of micrograin loading; note the very small but long brass tubing and the extra large funnel to hold the full ~4 lb load of micrograin propellant

I took photos of Osvaldo’s process at the last launch event with UCLA on June 2, 2018. The pictures and illustrations I have posted of the technique that has been successfully demonstrated at the MTA are hopefully clear enough to show the principle.

[12]
This was intended to the first topic, but Osvaldo circled back it at the end. Osvaldo successfully flew a parachute system in an RRS alpha. This is a feat that I don’t think has been in done in a very, very long time. Most of our alpha rockets come back ballistically and require back-breaking extraction by shoveling out of the hard-packed dry lake bed. It has been a general goal of the RRS to encourage more payloads to be flown in the RRS standard alphas as we do a lot of these flights. It has been a goal of mine to eventually fly a parachute system in the tight confines of the alpha’s payload tube. Osvaldo developed a pull switch that activates a timer chip inside to delay the firing of a small powder charge that ejects the parachute by means of a rising piston. This was discussed in the details of the same launch event with UCLA on June 2, 2018.

Osvaldo stands behind his RRS standard alpha parachute system successfully flown at the MTA on 6/2/2018

We did not have a lot of time to show all of the parts, but Osvaldo did mention that he will fly his parachute system again at the July 21, 2018 launch event with a modified timer design and break-wire system that is more compact. I may get Osvaldo to write a full detailed article on this subject in a future posting to come. This parachute system if proven to be repeatably effective may become a standard part of our RRS launch events with schools, but we must consider the added costs of producing them with standard costs we already charge for our RRS standard alpha. This is a really good topic and I’m sure we’ll be talking more about this in August.

[BONUS]
Richard Garcia treated us to a short video made by Microcosm back in 2001 with their experimental launch vehicle that did engine test at the RRS MTA. This dual-engine liquid rocket had thrust vector actuators and went through a successful hot-firing in the video.

Microcosm’s Scorpius-S-RM-20k vehicle test at the RRS MTA in 2001

The video showed the later rocket flight. We may post this on the RRS YouTube channel for everyone to see. It was a nice way to conclude our meeting with a rocket firing and flight.

[IN CLOSING]
We adjourned the meeting very late (well past 10:00 PM) which is only possible due to the kindness of our hosts at the Ken Nakaoka Community Center which closes at 9:00 PM. We are very grateful to them, but the RRS must strive to be more effective in our meetings to start on time and finish on time.

If there are any topics for next month’s meeting, please contact the RRS and make your suggestion. In the August meeting, we will likely discuss the July 21st launch and lessons learned from that event. We also have other events planned for this fall.

The next RRS meeting will be August 10th.

If there is anything I have missed or misstated, please let me know.
secretary@rrs.org

June 2018 meeting

The RRS held its monthly meeting for June 2018 on Friday the 8th at the Ken Nakaoka Community Center in Gardena. We were well-attended but got a late start on the agenda items. Wilbur Owens came back to see us again and has decided to become a member. Mohammed Daya who has joined the RRS also was able to stop by before the meeting started just to say “hello”. We were also glad to have Sam Austin back in town. Sam is a student at MIT interning at SpaceX this summer. He also paid us a visit both at the MTA on June 2nd and at the meeting tonight to discuss the liquid motor he built. There was lots to talk about at this June meeting between our outreach events and the hot fire testing.

RRS discussing things before the June 2018 meeting starts

A lot to talk about at the June 2018 meeting

[1] The RRS event at the Two-Bit STEAM Circus in Hawthorne was quite a success. The RRS was a bit short-handed, but we have great volunteers that stayed busy the whole time. The air rocket launcher was one of the big hits at the Circus event and we have been invited back for the next event in September. Frank made some improvements to the paper rocket template that is cut, folded and secured with tape to make the narrow tubes with attaching fins that comprise a paper rocket for the pneumatic launchers we have. The build process can be challenging for some, but it always is satisfying to see the finished product fly. The RRS is glad to have these events and we will surely do more.

Here’s some photos that Osvaldo took at the event.

RRS at the Two-Bit Circus STEAM Carnival in Hawthorne, CA. Frank works with kids to make the paper rockets for the RRS air launcher.

The air launcher is made ready to fire a paper rocket.

On a side note to this topic, USC is having a CRASH STEAM Carnival in 2019. We were invited to attend this year’s carnival, but the RRS is shorthanded and couldn’t support. We hope to expand our society to be able to come out for more events across the great city of Los Angeles. We’ll have more information on this event later.

[2] UCLA held their launch event at the MTA on June 2nd. The event was two-fold, it was the final project for the UCLA rocket propulsion class taught by Dr. Spearrin. It was also an opportunity for the UCLA Rocket Project team to static fire their hybrid motor. The event was a success for the class with the winds being nearly calm for most of the day. The small hobby rockets with F-sized motors reached good heights without being carried too far by the winds. Each had an altimeter and a hard-boiled egg as a payload that had to be safely recovered. Most were successful, but others not so much. A full write-up was done on an earlier RRS posting.

RRS MTA launch event – 2018/06/02

As a further note, UCLA was using a Jolly Logic Altimeter 3 model in their hobby rockets. These devices used by UCLA have proven to be very reliable and easy to use. The RRS will acquire some of these to fly in the payload tube of an alpha rocket to see what heights we reach in this micrograin mainstay rocket of our society.

Jolly Logic Altimeter 3 – manufacturer’s site

After UCLA’s static firings of their hybrid motor, the RRS flew an alpha rocket with a parachute system. This is a first in a long time. Osvaldo’s design had a safety switch to engage the battery only when the rocket is loaded to prevent it from getting depleted in waiting for launch. The parachute system also had a pull pin to start the timer circuit when the rocket lifted out of the rails. Osvaldo did bring another prototype of the alpha parachute system to discuss its features at the meeting, but we didn’t have enough time.

Osvaldo’s parachute deployment circuit that fits in a standard alpha rocket

After the June 7 launch event at the MTA, Osvaldo managed to find an RRS standard beta launched by UCLA last year. Although the payload segment sheared off in the extraction process, the nozzle is the precious part that can be cleaned up and reused.

RRS standard beta recovered from the RRS MTA; payload segment was not recovered

Osvaldo was also kind enough to make the adapter piece necessary for testing the RRS standard alpha second-stage solid motor I designed in the horizontal thrust stand at the next event. With this simple doubled-ended adapter that goes in place of the nose cone, the second stage motors once finished can fit into the load cell adapter and the RRS can get thrust measurements. Chris Lujan is working on a sucrose-KN solid grain and Larry Hoffing is working on an AP/HTPB/Aluminum motor grain. I have done the preliminary calculations for both and pressures should be appropriate for the 1.75″ aluminum payload tube. More discussion on this topic in future posts.

RRS alpha second-stage load cell adapter piece for the horizontal thrust stand. It goes in place of the nose cone.

[3] The next RRS build event with the LAPD CSP officers will be with another group of kids in the Jordan Downs housing projects of Watts. We’ll get started next week, 6/15/18, and run six educational sessions on Friday’s and Saturday’s until the launch event at the end of the program at RRS MTA. This will take place on July 21, 2018. This had to be re-scheduled due to the extreme heat predicted for the original date of July 7th.

The students will paint and assemble a set of RRS standard alpha rockets. More alpha rockets means more fun for our guests and also more opportunities for our RRS members to try payloads. It’s my hope we can demonstrate another one of Osvaldo’s parachute systems and fly an altimeter chip if we can secure one in time.

Richard Garcia said that he already has an Eggtimer Quark chip which has an altimeter. I had the chance to meet Cris Erving of Eggtimer Rocketry at the last Rocketry Organization of California (ROC) launch event in Lucerne Valley on June 9, 2018. I hope we can get an altimeter payload ready to fly in a standard alpha payload tube by the July 7th launch.

Eggtimer Rocketry

Rocketry Organization of California

[4] The new RRS membership card design has been finished. Many thanks to Bill Janczewski for pulling this together. We have had a few requests for membership cards from members and the RRS has agreed to produce these only on demand.

Jim Gross will be the first recipient of this new style of RRS membership card. This year’s design has the 75th anniversary watermark on it.

The new 75th anniversary RRS membership card

There was some general discussion about the payment of dues. Even as we are growing in membership in our society, the RRS has not been collecting dues on a regular basis. We’re content to primarily use the honor system and gentle reminders to our membership to pay their annual dues of $40 per year or student memberships at $20 per year. It is this small revenue that helps the RRS stay on top of our bills. Student memberships are good as many university projects can require multiple tests at the RRS MTA which is covered with signing the RRS indemnification form and paying membership dues to the RRS.

All membership applications must be sent to the RRS president and approved by the RRS executive council.
president@rrs.org

Payment of RRS dues ($40) and the added cost of a membership card ($5) can be done by check and through the Paypal donation button we have on the RRS.ORG website. It’s important to make a note on Paypal that you’re paying your Membership Dues. The extra price of $5 for membership cards is pretty small and compensate for the cost of low-volume production as most members may not opt to get one. To those desiring a membership card, please contact the RRS secretary.

secretary@rrs.org

For all of our regular membership, I had proposed that the RRS return to using membership cards which were used in the past in the society. Membership cards were issued to all members upon payment and re-payment of their annual dues. This provides a physical mechanism to verify that each member is in good standing with dues paid. The membership cards would have their name and an expiration date that says when annual dues must be paid again.

Although some felt the idea had merit, others felt that we should continue to have the council take the initiative to track payments and remind members to pay their dues as we have been doing. Since members join at different times in the year, this can get complicated but we will rely on members to stay on top of this.

It was a good discussion that also raised issues about what constitutes “active status” in RRS membership and our broader membership policies including corresponding membership for those who live outside of the Los Angeles area but want to remain a part of the RRS in some capacity. It was agreed to revisit this broader topic in the July 2018 meeting as some of our newer members may not be familiar with the past and current membership policies at the RRS.

[5] Sam Austin gave his presentation the Hercules Rocket Engine project at MIT. His liquid rocket propellants are LOX and kerosene. Sam was kind enough to bring his liquid motor that he is finishing. It’s a 500 lbf, 600 psi LOX-kerosene engine with an unlike impinging injector. His stainless steel chamber with a graphite nozzle insert ought to hold up to short burn durations. Everyone was able to inspect the injector, chamber and nozzle parts that Sam made at the MIT machine shop. The delicate work to get a clean injector pattern was impressive. He’ll be water flow testing the injector soon to verify that everything looks right.

The RRS recommended Specialized Coatings, a ceramic coating vendor in Huntington Beach, that we have used with success in the past on alpha and beta nozzles.

Specialized Coatings – Huntington Beach, CA

Sam Austin’s liquid motor nozzle with graphite throat

Sam Austin’s injector assembly for his liquid rocket

Sam is still working on the propellant feed system. He already has a pair of liquid carbon dioxide vessels that are of the right size. After safely removing the original valves and getting the rest of his control plumbing, he will hopefully have what he needs to conduct testing at the RRS MTA or at FAR next month in July 2018.

There were a few questions about different features of Sam’s liquid motor, but overall it looks like it should work. Sam is getting prepared to finish the propellant supply system for a static fire of this rocket motor. With luck, he should be able to get into hot-fire at the RRS MTA or FAR site next month and hopefully before he returns to MIT in the fall. We are glad that Sam has decided to join the RRS as a student member.

The RRS membership had a few suggestions for improvement and a few recommendation for low cost regulators, ball valves and relief valves that have been used in other amateur and professional projects.

[+1] We managed to talk about one bonus topic by showing the video from the vertical static fire of the vehicle-sized solid motor by Jack Oswald and his team at the RRS on Thursday, June 7th. The video clearly shows a nozzle failure after two seconds from start, but it seemed that there may have been grain fracture leading to a partial blockage of the nozzle and then the resulting pressure surge shattered the nozzle. We may upload the video to our YouTube channel once we ask Jack and his team. Hopefully, Osvaldo can extract a few still photos from his footage. I think some of those stills will show an impressive start followed by a change in the flow pattern and abrupt failure with ejecting fireballs of propellant that followed. The RRS works safely and are glad to have our own remote testing site like the MTA to do these larger projects.

Sam’s presentation was very engaging, but we ran out of time before the Community Center closed at 9:00PM. We did not address all of our main agenda items or some of those added at the last minute. We will roll these topics to the July 2018 meeting.

* Osvaldo’s alpha parachute system and the video of its launch on 6/2/2018 at the MTA
* Getting a sign at our first metal gate as you reach the MTA
* Saturday morning seminars for members and how to get those started
+ Richard’s progress with the RRS standard liquid rocket
+ Discussion about the 2019 symposium

+ We did agree to discuss the topic of RRS membership policy and what constitutes being an active member.
+ Also, on the meeting agenda for July 2018 is the quarterly update on the SuperDosa project. I hope to have something ready to present by July 13th.

If there is anything I have missed or misstated, please let me know:
secretary@rrs.org

Again, we will have another launch event at the MTA on July 21th with the LAPD CSP program and member projects to be discussed later.

The next monthly meeting will be July 13th at the same place and time (7:30PM).