June 2021 Virtual Meeting


by Keith Yoerg (RRS Secretary)


The latest meeting of the Reaction Research Society took place last Friday, June 11th and had 19 attendees – including a guest presentation from the Clarkson University Rocket Club. We kicked off the meeting saying vitrual hello’s and catching up on personal updates – Dimitri is safely in beautiful Alaska but will be down to visit California and may attend an MTA event if one is hosted.

Screenshot of discussion during the monthly meeting

RECENT & UPCOMING MTA EVENTS

The group kicked off society business with Dave Nordling telling us about the highlights from recent events at the MTA – including liquid and hybrid rockets from the UCLA rocket teams. More details are available in the post from Dave here.

Dave also re-iterated his desire that the Reaction Research Society host at least 1 event at the MTA every month, and asked whether other members were interested in attending an event on Saturday, June 19. A few members expressed interest – and Osvaldo agreed to prepare a few Alpha rockets for Dave to possibly launch. The weather is forecast to be 111 deg Farenheit in the desert this weekend, so anyone attending will need to bring lots of water, sun protection, and other preparations to beat the heat!

GUEST PRESENTATION – CLARKSON UNIVERSITY ROCKET CLUB

David Nagy, Benjamin Ellis, and Tyler Brooks from the Clarkson University Rocket Club were our guest presenters for this month. The club is brand-new (it became active this year!) and these students are working to turn it into a fixture at the university in northern New York state. They are currently in the process of soliciting faculty support, building a composites lab, and procuring equipment to get the club off the ground

Clarkson University Rocket Club members working on building their high-power fiberglass rocket

David, the president of the team, has some previous rocket experience with both high power and liquid rockets – including a 9.5 kN pintle injector rocket engine. The team is currently building their own fiberglass, high power rocket from scratch which they plan to fly on a commercial, CTI 75mm solid rocket rocket motor. This scratch build is not only helping them build out their workspace to do filament winding and carbon fiber layups – they also intend to fly a 3D printed avionics bay with an avionics board designed from scratch. They hope to use the lessons learned from this project to inform work on future, more complicated projects.

David, Benjamin, and Tyler showing designs for a future planned project – a liquid bi-propellant rocket

The Clarkson University team solicited advice and opinions on their plans for a liquid bi-propellant LOX/Ethanol rocket. The design is currently in its early stages but the specifications are to have 500 lbf thrust, with a fuel-centered pintle injector. They predict that with a 15-second burn time they could build a rocket that would reach an apogee of 35,000 ft. Several RRS members gave their opinions on this design and other challenges involved with starting a fledgling club from scratch. I know many of the members are excited to see what these students will do!

WIRELESS LAUNCH CONTROLLERS

We decided to do a short recap of our recent discussions and presentations from vendors of wireless launch controllers. Dimitri offered to let us use his Cobra system when he returns to California in July, and there was talk of attempting to launch 16 low-power kits at the same time to further test/prove the efficacy and safety of the controllers. RRS members seemed generally impressed with the presentation from Cobra last month, but concern was raised that it’s not a necessary expense. There was a bit of a debate about whether laying and coiling several hundred feet of igniter wire is triple-digit changes the calculation, but Osvaldo has graciously offered to be the cable spooler for any project that requests it.

MTA PERMANENT BATHROOM STATUS UPDATE

The Executive Council updated the membership on progress with the permanent bathroom. After a meeting in Downey earlier this month, it was agreed that RRS member Wilbur would build the container in the LA area and then transport it out to concrete pads which will need to be built at the MTA site (along with a septic solution). The first step of this process has been completed – and the RRS has placed a down payment on a 20 foot “high-cube” shipping container to be used for the bathroom. A schematic of the container is shown below.

The current plan is still to build 2 of these 20-foot containers. Water will be supplied by a well and stored in a tank installed on top of the bathroom or a nearby storage container. The bathroom facility is planned to be located southeast of the Dosa building, alongside the existing storage containers.

NEXT MONTHLY MEETING

The next RRS monthly meeting will be held virtually on Friday, July 9th at 7:30 pm pacific time. Current members will receive an invite via e-mail the week of the meeting. Non-members (or members who have not received recent invites) can request an invitation by sending an email to:

secretary@rrs.org

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May 2021 Virtual Meeting

by Keith Yoerg (RRS Secretary)


The latest meeting of the Reaction Research Society took place this past Friday, May 14th and had 20 attendees – including a guest presenter and a project update from the Compton Comet team, which is composed of RRS members. We kicked off the meeting saying vitrual hello’s and catching up on personal updates.

Screenshot of discussion during the monthly meeting

UPCOMING EVENTS AT THE MTA

The group kicked off society business by planning for upcoming MTA events later this month. Wolfram Blume is continuing progress on the Gas Guzzler, but windy forecasts continue to limit his ability to do further launch testing. Osvaldo and Wolfram planned to visit the MTA on May 16th to do a practice setup for a future static firing and some housekeeping tasks at the property.

Osvaldo also informed the membership about an active day planned for Saturday, May 29th with groups from UCLA planning to do another static firing of their hybrid motor and a liquid rocket launch to 33,000 ft. and a team of students firing model rockets. Several additional RRS members expressed interest in attending this event.

GUEST PRESENTATION – COBRA FIRING SYSTEMS

Scott Smith, the founder of Cobra Firing Systems was our guest presenter for this month, continuing our recent discussions on wireless launch controllers. Scott has been in the pyrotechnics industry for 10 years, and developed Cobra into a 25-person company with roughly 14,000 customers around the word. They have worked with Mythbusters, Disney, and the US Military to name a few.

Scott describing the underlying technologies behind the Cobra Wireless Firing Systems

RRS member questions for Scott focused on safety, in particular the risk of misfires and adding a physical shunt to the system. The data is encrypted, includes checksums, and is built around a US-based company Synapse, which has allowed the company to avoid any reports of accidental misfiring due to stray wireless signals. Cobra firing boxes are modular in nature and allow for what the company calls a “slat” – which allows for a cap to be used as a physical, mechanical shunt on the system.

MEMBER PRESENTATION – COMPTON COMET

RRS student members Manuel Marques, Aarington Mitchell, and Tre Willingham presented on the status of their project the “Compton Comet” which is being built at the Compton Airport under the guidance of RRS members Waldo Stakes and Dave Nordling.

The Compton Comet team presenting to the membership

The rocket is a 75% ethanol & liquid oxygen bi-propellant rocket with a regeneratively-cooled engine. The engine is a surplus XLR-11 which should produce roughly 1,500-lbf of thrust, and was originally used in a group of 4 to power the Bell-X1 (the first aircraft to break the sound barrier). The rocket is estimated to reach an altitude of 20,000 km and will use a 2-parachute dual deployment recovery system.

THE FUTURE OF IN-PERSON RRS EVENTS

Members discussed the likelihood of in-person RRS events like the Symposium and meetings at the Gardena Community Center in 2021. It mentioned that the Symposium typically takes between 90 to 120 days to prepare, and it would be unlikely that the RRS would host one before spring 2022. There was a bit more of an optimistic outlook on the monthly meetings with a tentative goal set for a return to the Community Center in August (pending COVID restrictions).

MTA PERMANENT BATHROOM STATUS UPDATE

Designs and plans for the permanent bathroom structure at the MTA have been the main focus of the ongoing, twice-monthly meetings of the RRS Executive Council. Frank updated the membership on the current status of the project, which has gone through several iterations. Currently, RRS member Wilbur is working with professional drafters to get precise designs on paper – including model numbers for things like toilets and water heaters. A precise, written design will help the society get a final product that matches expectations.

The current plan is to build 2 or 3, 20-foot containers with 2 bathrooms each or 1 bathroom and 1 shower. These will be transported to the MTA and installed on concrete plinths which drain to a concrete septic tank and leach field. Water will be supplied by a well and stored in a tank installed on top of the bathroom or a nearby storage container. The bathroom facility is planned to be located southeast of the Dosa building, alongside the existing storage containers.

RRS BY LAWS

The RRS Executive Council has reviewed the recommended changes to the By Laws provided by the 2020 constitutional committee. Following are the By Laws as agreed to by the 2021 RRS Executive Council:

2021 RRS By Laws

LAUNCHING & STRUCTURES

Richard Dierking raised a question regarding the new structure being built on the Polaris land adjacent to the RRS site, and whether it must be considered an occupied structure during launch testing at the RRS site. This prompted a lively debate about the nuances of the regulatory framework around rocket activities in the Mojave desert, with several members voicing their opinions.

Safety of all personnel must be the #1 priority during activities at the MTA & communication between between the RRS, FAR, and Polaris is the best way to ensure that. Concurrent operations at adjacent properties are avoided when possible, and the RRS maintains relationships with our neighbors so that the Pyrotechnic Operator in charge is in contact with & can ensure the safety of personnel at adjacent property when operations overlap.

NEXT MONTHLY MEETING

The next RRS monthly meeting will be held virtually on Friday, June 11th at 7:30 pm pacific time. Current members will receive an invite via e-mail the week of the meeting. Non-members (or members who have not received recent invites) can request an invitation by sending an email to:

secretary@rrs.org

MTA Launch Event, 2021-04-10

by Keith Yoerg (RRS Secretary)


The RRS held a launch event at our Mojave Test Area (MTA) on April 10, 2021, the day after our monthly meeting. COVID-19 still remains a threat so everyone continued to observe protective protocols – masks & physical distancing. For the first time in months, we had a day with great weather for launching rockets and we made the most of it! We had low-power, high-power, and experimental solid rocket launches, another launch of Bill Inman’s Solar Cat, the maiden voyage of Wolfram Blume’s Gas Guzzler, and a static fire of Larry Hoffing’s solid power motors. Osvaldo Tarditti was our pyrotechnic operator in charge.

Activity around 9:30 am at the MTA – prep work ongoing for CTRL+V (left) and Solar Cat (right)

CTRL+V (USC RPL)

Preparation for the first launch of the day: CTRL+V actually began the day before launch with motor integration and other preparation work taking place at the MTA site. On the morning of the launch, the team from the USCRPL installed the rocket on the launch rail, which was then raised into place south of the MTA’s vertical test stand. Wires running from the rail were staked to poles and hammered into the ground to provide additional stability for the rail. Several launch crew members can be seen prepping the rocket above, and a still image of the launch of the rocket can be seen below.

Launch of USC RPL’s CTRL+V, the smoke took a strange path up the rail faster than the rocket!

The rocket flew on a 6″ experimental rocket motor. A specific procedure was followed prior to launch, under the supervision of the pyro op, which included radio go/no-go call outs from several teams including tracking, avionics, and even a drone that took footage of the launch! All spectators and crew were in the bunker during takeoff at 11:04 am – ignition was prompt and rocket left the rail quickly and cleanly. The initial telemetry reported by the team indicated an altitude of over 11 km. Several members then went off on the daunting task of recovering the rocket from wherever it landed.

LUMINEER (BPS.space)

The next flight of the day came from BPS.space with the rocket Lumineer. This launch was conducted from one of the pads just west of the vertical test stand. The flight took place around 1:20 pm on a commercial Cessaroni “N” motor and was livestreamed to a reported 9,000 viewers on YouTube. The rocket utilized a “fly-away” rail guide to provide stability and eliminate the drag of rail buttons, which can be seen still in the process of falling from the rocket in the image below. The target altitude was 10 km, but telemetry was lost shortly after takeoff so the actual peak altitude was unclear after launch, and the rocket was not recovered for some time.

Launch of Lumineer from BPS.space

GAS GUZZLER (Wolfram Blume)

Wolfram Blume has been diligently making the pilgrimage to the MTA events over the last several months and the weather has been uncooperative for his chances of launching, but that finally changed in April! The maiden voyage of the Gas Guzzler took place from the pad just west of the vertical test stand. This flight was conducted to answer several questions about staging during the flight – so the ram jet second stage was flown empty and only the first stage, commercial solid rocket motor was used to power the rocket. A slow-motion (10% full speed) video of the launch can be seen here.

Launch of Wolfram Blume’s Gas Guzzler, it’s so calm the flag on the vertical test stand isn’t waving!

The ascent of the rocket was smooth, validating the rigidity of the rocket’s design and the stability when empty. The data from onboard altimeters confirmed that the ram air entering the 2nd stage was enough to separate the 2 stages immediately (0.1 second) after motor burnout which occurred at 1,440 ft. The parachute for the booster stage deployed successfully and that stage was recovered without damage. The ram jet, upper stage utilizes a dual-deployment of a drogue parachute at apogee and main parachute at 1,000 ft above the ground. While each of these deployments were successful, the main parachute did not pull out of the deployment bag so the stage landed hard and damaged a few parts. Fortunately, the 2nd stage is not the final parts intended for the full flight of both stages so there will not be delays to the project to rebuild. Wolfram collected lots of useful data and plans to add a GPS tracker and other upgrades before his next flight. We all hope the weather remains in his (and all of our) favor!

CHARLIE HORSE (Keith Yoerg)

Up next was the 12th flight of Keith Yoerg’s rocket Charlie Horse. This was the first flight test of the LoRa GPS tracking boards discussed in previous reports. There are several difficulties with getting the units setup properly, not least of which being the frequent firmware updates required to pair the board with the mobile phone app (2 updates in as many months). Powering up the boards the night before would have helped eliminate these struggles, but a successful launch was still completed, a slow-motion (10% full-speed) video of the launch can be seen here, which was on a commercial Cessaroni I280-Smokey Sam motor.

Keith Yoerg’s Charlie Horse seen through the smoke of launch – the camera was tipping over!

One issue still to be resolved with the LoRa trackers is a setting within the Meshtastic mobile application which trades off tracking range for the speed at which new information packets are sent. The “medium” setting was used on this flight but for rocket flights it may be advantageous to reduce the range (which is purported to be up to 10 miles) in favor of more frequent location updates. More testing will be done on future flights in hopes of developing a cheap, simple GPS tracking available for rockets flying at the RRS.

SOLAR CAT (Bill Inman)

Bill Inman’s solar-heated steam-powered Solar Cat rocket took to the skies around 4:31 pm. While the weather was perfect for most of the projects, the light overcast that can be seen in the pictures above proved problematic for the solar heating required for the best flight. In addition by launch time, the solar collector was at its westernmost limit so no more heating was possible. At launch the water temp was 370 F and was at 130 psi.

Bill Inman’s Solar Cat takes to the skies for it’s 2nd launch at the MTA

The flight reached 41 mph speed and achieved a 60 ft altitude. While this was an improvement on the first Solar Cat launch at the MTA, with additional heating there could be even more impressive stats. While he can’t control the clouds, Bill hopes to arrive at the MTA site the night before a launch in the future to increase the chances ¬†of getting off a good test and launch before reaching our western limit of travel for the solar collector.

THE YOERG CHALLENGE (Dimitri Timohovich & Keith Yoerg)

With this being Dimitri’s last MTA event before leaving to Alaska for the summer, some other RRS members need to step up to the plate to keep the “Yoerg Challenge” alive. I have put out the call for more RRS members to build low-power rockets to fly at the MTA, and have left my 5-pad PVC launcher at the site for future launches. IT’S CHEAP, IT’S FUN, IT’S A CHALLENGE (and everyone is a winner)! What’s not to love? So get out there and build some model rockets!

The remains of the “Space Crater” – not covered in raw egg!

The entrants this month included Keith’s Big Bertha, Baby Bertha, and Hi-Flyer XL rockets and Dimitri’s Space Crater – which carried eggs in honor of Easter this month. Fortunately, Dimitri’s wife had the foresight to hard-boil the eggs because his rocket took the “Crater” part of its name a bit too seriously (the remains are shown above). A few of Keith’s flights before the GoPro battery died can be seen here.

SOLID MOTOR TEST FIRE (Larry Hoffing)

Larry Hoffing had some experimental solid rocket motors ready to test fire, but with all the other activity going on at the site he took the time to install a new “No Smoking” sign on the covered propellant loading area (shown below). Once things were a little less active, Larry was able to affix the motors and perform a test-fire. While the burns were long, they did not produce much thrust and need to be improved upon before use in a rocket.

No smoking sign added to the covered propellant loading area by Larry

CONCLUSION

In addition to everything detailed above, one of the USC RPL members flew a high power rocket to earn her Level 1 certification with the National Association of Rocketry, and Dimitri flew his water rockets with his son.

This was by far the most active event at the MTA in the past year and was an exciting day for anyone who likes to see rockets fly! Our next launch date has not been decided upon, but we hope to have an event in May to continue hosting at least one event per month at the site.