The RRS held a work event at the Mojave Test Area (MTA) on Saturday, January 20th. The primary purpose of this meeting was to give Joel Feree, our contact with the Los Angeles County Museum of Art (LACMA), an in-person tour of the whole MTA, so that he could get an idea as to what we were working with for our collaboration with American Artist which will involve the recreation of the 1936 Guggenheim Aeronautical Laboratory at the California Institute of Technology (GALCIT) prototype liquid rocket engine. This was Joel Ferree’s first time at the MTA and he gained much insight into how we’ll be seeing the project through. Dimitri Timohovich also used his experience in the film industry to highlight some practical aspects for the production. Following this meeting, Dave Nordling, Dimitri, and Joel Ferree came up with a timeline for the project. Dave Nordling, serving as the project leader, is working hard to get hardware ready for an initial firing by our membership at the MTA. Once the system is proven to work reliably and safely, the static firing of this replica will be the centerpiece of the filming to take place at the MTA.
On the same day, four student representatives of Loyola Marymount University’s rocketry team came to meet with Dave Nordling. They intend to build a custom hybrid motor, which they plan to static fire at the MTA. Dave gave them some points on their motor and feed system designs, which they can certainly appreciate, given that this is their first experimental rocket project. Rushd Julfiker and Dave will continue to advise the team on their propellant loading system and ignition system, and they may well use a firing box of Dimitri’s design.
While there, Dave and Dimitri worked on moving some of the society assets from the Dosa Building to the new Bldg. 14 office container. This was done partly to declutter the working space, in order to make it into a meeting and workspace once more. If the lease does end next year, then Polaris will be removing many items of theirs which are also in the Dosa Building, including refrigerators, stove, and laminar flow bench. Polaris is required according to the terms of the lease to notify the RRS Executive Council of the movement of their assets.
According to Dimitri, a company called Tortuga Industries has reportedly bought 183 acres of land along Munsey Road. According to the rumors, they are looking to turn their parcel into a private duck hunting reserve, complete with a large pond.
Dimitri also reported that Crisalli is taking the initiative to fix the northern road running along the eastern side of the MTA property. Gordon has so far filled in the trench near the northeastern corner of the property, removed the concrete barricades, and installed a gate across the road. He has reportedly been using this northern route himself, dragging it several times in the process. He reports that the 4 miles of the northern road leading to the highway is now certainly passable, albeit the creek bed is still soft as of this writing. The RRS still recommends all visitors and users of the MTA continue to use the western (Munsey) road from Cantil until further improvements can be made. The RRS MTA has access gates along the eastern border but they are rarely used.
Next monthly meeting will be February 9th.
Next work event at the MTA is planned for February 17th. This will depend on planned Polaris operations which could close the access easement road. Coordination with Polaris will be required.
The RRS held a launch event at our Mojave Test Area (MTA) on March 20, 2021, the spring equinox. COVID-19 still remains a threat so everyone had to observe protective protocols. We had a lot of wind that day making launch impractical, but we still were able to get many things done that day including another static fire of a hybrid motor, some system checkouts of the Gas Guzzler and a possible flight of the Solar Cat steam rocket. Osvaldo Tarditti was our pyrotechnic operator in charge. Also joining us that day was fellow Rockets 2nd Class pyrotechnic operator and RRS member, Jim Gross,
MOBILE TRAILER CLEANUP
Mike Gottlieb was a lifetime member of the RRS who passed away over 2 years ago. Years prior, he had acquired a surplus mobile trailer from the former Rockwell International company which was left to reside at the RRS MTA. By permission from his surviving family, this single-axle, climate controlled trailer has been donated to the society. The trailer was opened by the RRS president and the interior inspected by our members present at our March 2021 launch event.
For now, the space will be used for light storage until more space can be acquired elsewhere. We used the time to reorganize the contents of our storage trailer. We hope to renovate this new mobile trailer soon and restore its climate control systems which will be convenient in the summer months.
PUBLIC ADDRESS SYSTEM AT THE MTA
During the cleaning and reorganization of our storage space, we pulled out the public address equipment we had. The 12 VDC battery powered system including loud speaker and microphones worked well in a test from the old blockhouse. The society has talked about having a more distributed system around the main areas of the site. This will require some further equipment purchases, but for now we have a core system to start from. The goal is to make coordination of our events easier to do when we have large groups of people at the MTA again. Further still, we’d like to coordinate launch timing better with our neighboring amateur rocketry group (FAR) to our south.
NEW RESTROOM FACILITY
As discussed at the March 2021 monthly meeting, the society is going forward with building a new restroom facility with flushing toilets. This will be a big convenience to our visitors and members alike. The executive council has received bids and plans for the restroom and is working with suppliers to find the best solution given our budget. We are grateful to our generous benefactor and the many people who supported this project with their time and skills. More progress should be made soon as we would like to deploy this facility before the hot summer months arrive this year.
FIRST FLIGHT OF THE SOLAR CATFROM THE MTA
Bill Inman and new member Jonathan Wells returned to the MTA for another attempt to launch the solar powered steam rocket, the Solar Cat. He has been making many adjustments and had his first launch near his home in Carson City. Today would be his first launch of his Solar Cat from the MTA.
Bill was able to work out minor problems on his trailer mounted systems last month and was fully ready to use his solar heating and tracking system for the hours necessary to reach launching temperatures of the stored water load in his steam rocket.
Bill has had some minor problems with the release system which led to a unintended release of the rocket. No one was injured but it did cost him several useful hours for insolation (heating). His second attempt was only a partial heat load but sufficient to conduct the first (technically second) flight at the MTA. Keith Yoerg managed to capture the short flight in the late afternoon. It’s a bit comical to watch given how short the flight was, but it is a significant milestone in getting this non-traditional form of liquid propulsion to work. We look forward to the advancements, Bill will make for future flights from the MTA.
REBUILD AND SYSTEMS CHECK OF THE GAS GUZZLER
Wolfram Blume had made several improvements since his last flight attempt of his two-stage ramjet-solid motor rocket. He was able to correct software issues but also made physical feature changes to his booster. Wind speeds were excessive for much of the day, so he used his time at the MTA for fit checks while on the 1515 rail launcher.
Wolfram was able to conduct his tests making use of the 1515 rail launcher. He left in the afternoon after completing his tests and will return for our next launch event planned for April 10. 2021.
WIRELESS FIRE CONTROL AT THE MTA
Wireless fire control is a remote means of conducting launch without stringing long wire connections. This has been a controversial subject at the RRS with some of our members actively supporting using these systems and others being skeptical about their safety.
Richard Dierking mentioned the Wilson F/X wireless firing system which has been used at the Rocketry Organization of California (ROC) and at the Friends of Amateur Rocketry (FAR) site. Fellow RRS member, Dmitri Timohovich, has used Cobra Firing Systems for pyrotechnic events in the movie business with success. He brought one of these systems to demonstrate at the MTA with test bulbs. The 64-bit encryption in this system vastly reduces the possibility of stray signals causing an unintended firing.
A decision was made at the March 2021 meeting to proceed with care by testing one of these wireless fire control systems with only low-power simple model rockets. We also thought meeting with a sales representative or technical advisor from a wireless fire control system manufacturer to explain the safety of these systems to the society would be an excellent idea. Some of our members have had a negative experience with these systems with unintentionally firing. Older wireless fire control systems have had safety issues. Safety in operations with pyrotechnics of any kind is of paramount importance.
The RRS plans to educate themselves further about wireless firing system technology before making any further policy decisions. It is agreed that every pyro-op in charge at the event has the final say about what systems are and are not allowed at the event. The best course of action for any project leader is to discuss all aspects of their test or launch with the pyro-op in charge well in advance of the event at the MTA.
STATIC FIRING OF THE HYBRID MOTOR
The last two firings of the Contrails H222 38mm 16-inch hybrid motor left some questions about how reliable the ignition of the motor is. From both prior flights, it was evident that quick severance of the nylon plastic fill line at the launch command was not happening. Altitude was very low from such a powerful motor according to the curve. Since the last flight damaged the rocket body beyond repair, the next firing was intended to watch the startup sequence in careful detail under static conditions.
The motor survived in tact from the last short flight, The nozzle, spent grain and floating injector were shoved forward from the impact, but all parts were able to be removed, cleaned and reassembled for another firing with the last of my three fuel grains from the kit.
The static test firing was done on the vertical test stand using a simple wooden fixture and 1/2-inch fasteners. The fixture was built quickly and unfortunately not perfectly. We had to fire the motor upside-down which is not representative of how the engine flies.
The igniter used in the 3-20-2021 test used an electric match as was done in the second test. The kit comes with an electric resistor. In the first test, this was insufficient to get ignition and sever the fill line. Second firing used an electric match and a fragment of composite propellant. This achieved ignition but the fill line wasn’t fully severed. The third attempt used a similar load with a bit more composite propellant. The idea was to produce an ignition flame hot and fast enough to soften and sever the pressurized nylon fill line, With the escaping oxidizer liquid, the combustion should be enhanced and help sever the line. In practice, this doesn’t seem to occur quickly enough,
In the hybrid firing that day, the igniter fired and some chuffing from the nozzle was seen but the combustion was not sustained and the oxidizer supply emptied. The motor will be disassembled and inspected to see if all the composite propellant was consumed or if the nitrous oxide dispersed the pack before the full burn could finish.
MORE WATER ROCKETS
Dmitri upgraded his water rocket launch system to fire multiple rockets. He had a remote firing box which made it very easy to set up. The winds were too strong for any high altitude flights, but the modest water rockets were plenty of fun.
The Yoerg Challenge started as a simple request to those attending our meeting on March 12, 2021 before the launch event: build as many model rockets from as many people as possible and launch them from the multi-wire launcher array that Keith built last month. Dmitri and I both answered the challenge for the event, Although many of our members have built many model rockets since they were kids, some of have not. For those experienced and inexperienced, the Yoerg Challenge was issued. More rockets at each successive event inspires others to build more rockets and more ambitious rocket builds. The RRS is for all forms of reaction propulsion even with a simple model kit.
At the end of the day, Keith and Dmitri launched their model rockets using small “A” sized motors to keep their altitudes low and avoid being carried far downrange with the high winds. I decided not to fly my first model as I left early that day. We hope others will build and bring theirs at our next event.
Next launch event will be April 10, 2021, with USC and member projects.
The Reaction Research Society held its first launch event of the new year on Saturday, January 9, 2021. Dave Nordling was the pyro-op in charge. We had a couple rockets prepared and some maintenance work we wanted to continue. Dmitri Timohovich brought his whole family to the event and we enjoyed grilled burgers there at the Mojave Test Area. The January winds were light and cool that day. It was a good day for launch.
Wolfram Blume brought his two-stage rocket, the Gas Guzzler. His ramjet upper stage was rebuilt from last year’s unfortunate breakage when dropped during loading on the launch rail last year. 3D-printed plastic parts can sometimes be very brittle and care must be taken.
The 1515 launch rail was put into position with some help from Bill Inman and a few others. Bill Inman is still working on his solar tracker for his latest iteration of the Scalded Cat. He made the trip from Carson City to the Mojave Test Area to help others with operations and we were very thankful.
Wolfram was able to mount his booster stage on the rails and carefully erect the launcher. The booster uses a commercial solid motor, an Aerotech “K” motor.
The ramjet for this first flight was loaded with water to simulate the weight, but would not be fired. The primary goal was to demonstrate the staging and recovery systems powered only by the booster. Wolfram went back to the loading area to complete the preparations of the upper stage. During a system checkout, the parachute deployment charge fired. After some careful examination, the source of the problem seemed to be related to errant software commands. Wolfram aborted his launch attempt and returned with his rocket stages for further examination back in Los Angeles. Although the charges could be reloaded, he could not be certain that an early parachute deployment would occur and wreck his vehicle during flight.
Dmitri Timohovich and Waldo Stakes worked on completing the welding of the new steel plate on the vertical test stand. This plate on the vertical test stand was damaged during a test failure many years back and late last year was finally cut out and the space grinded to fit a replacement plate. Unfortunately, the stick welding system would require a different type of welder and a more powerful source to drop a reliable weld. The welding of the plate will be reattempted at the next event.
The second launch of the day would be Dave Nordling’s nitrous oxide hybrid rocket. This 38mm H-sized commercial hybrid motor kit from Contrails Rocketry (H-222 model) had a modified igniter and was mounted in a new 4-inch body made by Larry Hoffing. The prior launch attempt had issues with severing the nylon plastic filling line so the ignition energy was increased with small bit of composite solid propellant ignited by an electric match.
Several minor problems occurred during launch preparations. The nitrous bottle and manifold filling system was working well but the electrical control box failed during tests. After some discussion, the defective switch box was removed and we were able to fire and get a clean launch
We repacked the motor before launch and adjusted the vent tube to be more visible. The filling of the rocket went quickly and smoothly, only about 20 seconds before the white stream of liquid could be seen. The filling was stopped and with a short five-count and the rocket was fired. The rocket came off the rails quickly and it seemed that the modified igniter worked. The big problem was the parachute recovery switch wasn’t turned on before launch. This simple oversight would mean a rebuild would be necessary.
The rocket was recovered on the north end of the MTA site. It only seemed to reach about 300 feet of altitude. Unfortunately the ballistic landing broke both stages and the internal motor mounts and a complete rebuild is necessary. The motor case was parts were in tact and so it was extracted and will be reloaded,
Beckie Timohovich recorded the hybrid flight on her phone, The rocket seemed to immediately curve to the north off the rails opposite of the wind. It seems that the nylon fill line might be still holding fast despite the added solid propellant charge. The 3/16-inch nylon plastic line being strong enough to hold back the 900 psi nitrous pressure, it also poses a challenge to cut cleanly from the ignition charge. A static firing of the motor will be done next to get a better look at how well the fill line severs and measure the thrust curve directly..
After recovering the hybrid rocket and putting away the equipment, we flew a water rocket for Dmitri’s young son. Although very simple, these things are very fun.
The event was a partial success and there is more work to be done on our facilities including adding a new toilet facility at our site and welding in the plate on the vertical test stand. The next hybrid rocket launch may be a couple months away, but Bill Inman may have his next design of his solar heated steam rocket ready for launch af fhe MTA in a few weeks. He had his first successful flight in the Nevada desert just before Christmas. He is getting ready for a flight from the RRS MTA.
Wolfram seemed confident that he too might be ready to try his first launch of the Gas Guzzler at about that same time. If the next launch event occurs before the next monthly meeting on February 12, 2021, the announcement will come through the society email list.