Static Fire Test of Hybrid Motor at FAR, 2021-04-17

Dave Nordling, Reaction Research Society


Based on the recent lacking performance of the Contrails H222 nitrous oxide commercial hybrid motor, a pair of static fire tests were conducted to improve the ignition and severance of the nylon fill line. The latest of these static firings was conducted at the Friends of Amateur Rocketry site south of the RRS MTA on 4-17-2021. This was done for simple convenience since I was unable to attend the MTA launch event in the week prior. Mark Holthaus and John Newman oversaw my static firing and offered good advice. Fellow RRS member, Dmitri Timohovich, joined me that day and brought his four channel firing box to conduct the remote fill and fire operations of the hybrid.

Dmitri connects the fill manifold to the nitrous oxide bottle at FAR
Orange fill and firing box for the hybrid motor
Fill, drain and firing circuit for a Contrails hybrid rocket motor. The separate vent solenoid valve hasn’t been added. Weight scale is also a separate feature and not necessary for operation.

Nylon is one of the stronger polymer tubing materials which can handle the 900 to 1200 psig nitrous oxide pressure when flow is supplied from the solenoid valve controlled manifold. The problem is that this strength makes it difficult to quickly and cleanly sever the Parker NBR brand, 3/16” OD fill line allowing the nitrous oxide to flow against the fuel grain while getting reliable ignition.

The original ignition method as designed by the manufacturer is a small resistor in place of an electric match and the use of a Pyrodex pellet which is essentially a pressed cylinder of black powder. The first flight attempt of the nitrous oxide hybrid rocket used this method but was not successful.

Contrails Rocketry, H222, 38mm, 16-inch high powered nitrous oxide hybrid motor

Earlier builds of the hybrid motor used electric matches and small scraps of composite propellant grain for a swifter and hotter ignition. The first two flights showed evidence of the fill line remaining connected. A better means of ignition and fill line severance was needed.

February 2021 launch of the hybrid motor in Larry’s 3-inch rocket body. It is clear that a hot plume is exiting the nozzle but the sharp arc to the north seems to indicate that the fill line is still attached.

The composite propellant is an ammonium perchlorate, aluminum powder and HTPB binder mixture with some red iron oxide used as an accelerant. These scraps were from RRS member, Larry Hoffing’s, small solid motor that he unsuccessfully tested at the MTA in 2019.

The Contrails H222 motor was mounted upside down due to the lack of a proper motor retainer feature. The static firing was the primary purpose which resulted in a feeble puncture of the filling line and no subsequent ignition.
The aft end of the hybrid motor mounted for static fire at the RRS MTA on 3-20-2021
Failed ignition resulted from the 3-20-2021 static firing. Disassembly revealed an excessive amount of electrical tape and an uneven burn around the fill line circumference was the most likely cause.
Previous solid propellant grain motor test in 2019 was a failure, but the remaining tailings from the casting were useful in boosting the ignition power in prior hybrid motor tests

The last static test at the MTA failed to achieve ignition and only created a small tear in the fill line without achieving ignition of the grain. The composite fuel grain fragments were getting clean ignition but the electrical tape wrapping method I used failed to adequately focus the high temperatures to getting clean ignition and severance of the black nylon fill line.

At John Newman’s suggestion, we used a small ring of composite propellant grain at the forward end inside the hybrid high-performance (HP) fuel grain. These were made from a 22mm cylinder that was cut to a 3/4-inch length and drilled out to a 3/8-inch hole size which is roughly twice the diameter of the black nylon filling line passing through. This larger hole would allow the electric match head to be in close contact with composite propellant ring. As the solid propellant charge burns it focuses the tremendous heat of combustion on the nylon fill line causing it to soften, extrude and cleanly sever.

John Newman uses his lathe at his shop to gently machine fuel grains for custom applications.
The ring of 22mm diameter composite propellant grain fits within the head-end of the hybrid fuel grain and can be pressed flush to the edge. A 3/8-inch hole is run through the 3/4” long segment to allow the nylon fill line to pass through with enough room for the electric match head
Floating injector (left) with the nylon fill line pushed into the Parker push-to-connect fitting. Composite propellant grain is pressed in flush to the edge and electric match head can be seen beofre it is secured to the fill line to get the proper position when the motor is assembled
Snap ring, graphite nozzle and steel nozzle washer finish the motor grain assembly inside the 16-inch aluminum body of the H222 model
The complete motor assembly clamped into the unistrut holding fixture. The clear vent line at the head end must protrude to the outside to give a visible and audible indication when the oxidizer volume is filled with liquid before committing to firing.
Dmitri Timohovich makes adjustments to the clamps holding the hybrid motor in place. Peak thrust is just above 200 lbf according to the official thrust curve data for this H222 model.
Four channel firing box sits at a safe distance from the static fire test stand.
Dmitri Timohovich (left) and Dave Nordling (right) pose next to the unistrut mounted static fire mounting of the Contrails Rocketry H222 high-powered 38mm hybrid motor ready for testing at the FAR site on 4-17-2021

With everything in place, we called over the pyrotechnic operators in charge for this FAR event. After inspecting the connections and describing the fill and fire procedures, we were authorized to begin the short filling process.

Successful ignition of the hybrid motor at FAR

The hybrid motor was loaded, fired, reloaded and fired again. Both times stable ignition was achieved and the fill line dropped out of the motor as expected. We had to abort the initial second firing as visual confirmation of the nitrous oxide completing fill was not apparent. Given the hybrid motor has a small weep hole in the head end of the motor means that given time the nitrous oxide will leak out safely. The clear 1/8” acrylic vent line had become tangled in the unistrut obscuring the liquid plume. Trimming the acrylic vent line helped to keep the tip more visible on the second and last firing that day.

Cheap and simple, the 3-inch Little John from Mad Cow Rocketry

The next step will be to purchase a 75mm rocket body able to integrate the 16-inch long, 38mm standard hybrid motor inside. The 3-inch Little John rocket from Mad Cow Rocketry was selected and should arrive soon. With luck, the rocket can be built and ready for 1010-rail launched flight at the next RRS MTA event on 5/1/2021.

The RRS is thankful for the support of FAR at their facility for this static fire. Dmitri and I conducted a safe dispoal burn of the scrap propellant. I was able to acquire a few more propellant ring segments for subsequent tests of the hybrid in flight. Later, we plan to revisit the Pyrodex black powder charges with the electric resistors as the initiator. It is not clear if this will be as effective as the high temperature composite grains and an electric match, but it is worth a try.

September 2020 virtual meeting

by the Reaction Research Society


The Reaction Research Society met on September 11, 2020, by teleconference. Several members called in from out of state. After calling the meeting to order and the reading of the treasurer’s report, we began to discuss events to come and those in planning.

Attendees of the Seotember 2020 meeting by teleconference

MTA WORK EVENT 10/3/2020

The next event at the Mojave Test Area will be on Saturday, October 3rd. This will be a work event to repair our large adjustable rail launcher, remove tumbleweeds and brush from around our site, fix the two cut strands of barbed wire at our front gate, clean off corrosion from several areas and also potentially replace the bent panel on the vertical thrust stand. Osvaldo is leading the work event and all members are encouraged to come out. In addition to bringing sunscreeen, proper desert attire and footwear, bringing work gloves will be very useful.

John Krell wearing his facemask standing before our front gate with two of the barbed wire strands cut. This is one of many things to be repaired at the MTA.
Bent panel on the vertical test stand
The 8-inch adjustable rail launcher is still under repair from the failed July 2019 launch. The inner adjustable rail slides are being built from scratch. One of the outer braces was blown off and some of the angle frame pieces are distorted. This will require a lot of rework but we hope to have this launcher back in service soon.

As with all events at the MTA, social distancing and facemasks are required by all attendees at this event. Newcomers must request permission to attend and sign our indemnification waiver in advance of their arrival. See our website for these forms and submit them to the RRS president.

At this same event, we may also have a few launches if members are ready to do so. Dave Nordling was appointed to be the pyro-op in charge for this day. Wolfram Blume had planned to attempt his first flight of the two-stage Gas Guzzler to verify the staging and recovery systems. The nitrous-oxide hybrid motor is also ready for another launch attempt at this event.

Bill Inman also plans to join us at the MTA to conduct some tests of his solar concentrator to be used with his next generation steam rocket still in build.

NEW RESTROOM FACILITY AT THE MTA

Last year, the executive council set priorities for improvements at the Mojave Test Area. At the top of the list was building a new restroom facility which would offer our guests greater comfort than the current facility.

Larry Hoffing and Dave Nordling have begun to approach potential contractors willing and able to build a modest facility at our site. No formal proposals have yet been received yet but the society expects to have more to share in the coming month. With the hot summer months receding and the cooler temperatures of autumn approaching it is a perfect time to begin this project.

Given our modest budget, we are asking for donations to help the society make this much asked for and much needed improvement. Donations to the RRS are tax deductible as we are a registered 501(c)3 educational non-profit group in California. Our Paypal link is one our website and if there are any questions please contact the RRS president or any member of the executive council.

2021 RRS SYMPOSIUM

It was recommended that we try to set a firm date for the 2021 RRS Symposium with the Ken Nakaoka Community Center on a Saturday in late March. Although it is not certain if the symposium can be held, preparation for the symposium can take many months. Frank was going to see if a tenative date could be established only for planning purposes. If COVID-19 restrictions in Los Angeles were lifted to allow our symposium, we would have little time for advanced planning. There’s liitle to lose in scheduling the event and postponing if it becomes necessary.

IN CLOSING

Contact the RRS secretary with questions. Next meeting will be held virtually on October 9, 2020, 7:30pm. Contact the RRS secretary for details.


August 2020 virtual meeting

By Dave Nordling, Reaction Research Society


In the absence of our secretary, I took a few notes from the meeting. This is what I recorded. Contact the RRS secretary for updates and corrections.

The Reaction Research Society held its monthly meeting by teleconference on August 14, 2020. Our monthly meetings are always held on the 2nd Friday of every month. We’ve had a lot of success with holding our meetings remotely and we will likely continue for the next coming months to continue our commitment to safety in light of the pandemic. Our membership is in regular contact with our community which has allowed us to promote and hold events including our first launch at the Mojave Test Area (MTA) on July 25, 2020. You can read the details in the firing report posted on this website.

Our members are doing well and thus far no one has reported being infected with COVID-19 which we hope continues to be the case. Frank is in regular contact with the Los Angeles Police Department’s (LAPD) Community Safety Partnership (CSP) but under current circumstances, the next school event may not be until next year. Options are being considered on how to continue our educational programs while maintaining social distancing.

The August 2020 RRS meeting held by teleconference.

REVIEW OF THE 7/25/2020 LAUNCH EVENT OPERATIONS

The first topic was the recent launch event we held on July 25th at the Mojave Test Area for the first time since the start of the pandemic. We had some difficulties in operating under the summer heat (106 Fahenheit at the peak) but this is nothing unusual for this time of year. Many of us were well prepared for the hot sun with our hats, sunscreen and iced beverages and chilled water. We also did a good job of watching out for each other. Still, the heat was responsible for leaving all but one of the micrograin rockets downrange. It also underscores the importance good planning, coordination and putting safety over all other considerations. We had several mis-fires which we were able to resolve, but maintaining discipline during the event proved to be a larger challenge. The launch protocols will be explained more thoroughly in the next safety briefing. The meeting highlighted that every member and pyro-op attending the event holds a joint responsibilty for the safety of all and it starts with self-discipline and patience by all.

Getting the beta rocket ready in the launcher on 7/25/2020 and setting the camera

We also discussed proper protocols such as announcing the pyro-op in charge well before the event and the necessity of providing detailed information about the intended operations to the pyro-op in charge in advance. Most of the planned projects were well understood as they were micrograin rockets and the previous hybrid rocket attempted at the last launch event.

DATA REVIEW OF THE STANDARD ALPHA FLIGHT OF 7/25/2020

The only micrograin rocket to be recovered from the launch event of 7/25/2020 was the standard alpha with plain steel nozzle. John Krell has been developing progressively better and more powerful avionics payloads designed to fit the narrow confines of the RRS standard alpha payload tube. John was able to spot and recover one of his payloads and process the flight data captured that day. The avionics payload was intact after being extracted from the desert floor including the solid-state data chip. John was able to recover the data and accurately reveal the huge acceleration of the RRS standard alpha with unprecedented accuracy. A peak acceleration of 114 G’s was recorded at roughly 0.3 seconds just before tail-off and burn-out at 0.4 seconds from launch. I was able to screen capture his plot below.

John Krell’s presentation of the data from the one recovered alpha ( to date).

The second plot shows the velocity derived from the accelerometer readings in the half-second which captures burnout at 0.4 seconds. Burnout velocity was measured at 670 feet/second which is consistent with prior data and trajectory predictions. The alpha is subsonic but travels at substantial speed from the swift acceleration. Given the high air temperature that day, 106 Fahrenheit, the speed of sound was 1165 ft/sec. The altitude of burnout was determined to be 130 feet which is consistent with prior flight data and high speed video footage.

Trajectory plot of the standard alpha flight from 7/25/2020

The third plot was made for the whole flight of standard alpha from the 7/25/2020 event from launch to impact at 35 seconds. Given the roets were impacting 2000 to 3000 feet downrange, the sound delay matches with the time to impact witnessed in the observation bunker. The maximum altitude was just over 4,400 feet based on the barometric pressure measurements using the 1976 standard atmosphere model. Base atmospheric pressure reading at the start of the flight shows the elevation of alpha launch rail platform is 2,048 feet.

Trajectory of the standard alpha flown on 7/25/2020

John Krell has really accomplished something with these custom avionics packages. He has been mentoring some of our other RRS members and the society encourages other members to build and fly their own payloads to spread the knowledge.

John Krell and Bill Behenna discuss avionics payloads

The society hopes to recover the other two alphas and the beta for further data analysis. Both of the unrecovered alphas from this last launch event had ceramic coated nozzles which should not erode. This should result in a more ideal performance as the throat area will not open up. The actual effect of this design improvement can best be assessed with recorded flight data. Also, we hope to compare the trajectory of the four-foot propellant tube with the standard length. Lastly. if the beta is recovered with recorded flight data, we may be able to assess its performance in unprecedented detail. The society hopes to report this flight data soon.

IMPROVEMENTS TO THE NITROUS OXIDE FILL/DRAIN MANIFOLD

The failure to launch the second build of the hybrid rocket was discussed at the August 2020 meeting. After discussing the launch procedures and corrective actions followed during the attempt to launch the nitrous oxide hybrid at the MTA with Osvaldo (the Level 1 pyro-op in charge) and racing experts at Nitrous Supply Inc., Huntington Beach, California, the cause of the fill valve’s failure to open became clear.

nitroussupply.com

In the racing industry, these normally-closed direct-acting solenoid valves are commonly used to open the flow of stored nitrous oxide bottles against the full supply pressure in the storage bottle. These are called “purge solenoid valves” among racers because it is this solenoid valve that opens the flow of nitrous oxide which displaces or purges out the air in the engine lines during the race. Buying these 12-volt DC high pressure solenoid valves from racing suppliers is much cheaper given they are made in greater numbers for the racing industry. (~$120 each versus $400+ each from reputable solenoid valve manufacturers).

In researching common designs for normally closed (NC) solenoid valves, the excessive heat of that day simply created too much inlet pressure against the internal valve seat for the electromagnetic solenoid coil to overcome and open the flow path. 1000 psig is likely the limit to reliably open these valves according to advice given by Nitrous Supply Inc. who has decades of practical experience at racing tracks around the country using purge solenoid valves for an application nearly identical to the needs of hybrid rocketry fill and drain operations. The ambient temperature at the MTA on launch day was creating a bottle temperature of 1400 psig accordling to the bottle pressure gauge and the separate pressure gauge in the manifold when the bottle was opened. This is well above the 900 psi recommended pressure range seen by marking on the gauge. The bottle, valve body and fittings are rated for these higher pressures, but opening mechanism of the solenoid valve was not.

A color-coded example of direct-acting normally closed solenoid valve is below. Blue shows the high pressure fluid path which is holding the seat down along with some assistance from an internal spring only for low inlet pressure conditions. With current applied to the electromagnetic solenoid (Orange), it pulls up on the moving armature (in red) which then allows the fluid to slip past the seal and through the flow control orifice when commanded open. Only a slight amount of movement is necessary to lift open the valve. However, if the fluid inlet pressure is too great, the solenoid can not provide enough force to lift and open the seal, therefore the valve stays shut.

Example of a direct-acting normally closed (NC) solenoid valve courtesy of M & M International (UK) Limited with color added to distinguish key parts.

To understand the relationship between pressure and temperature of the nitrous oxide you must consult the vapor pressure curve for nitrous oxide. This set of data points spans between the triple point and critical point of any pure fluid. NIST provides accurate data to generate such a curve.

webbook.nist.gov

nitrous oxide (N2O) liquid state properties, HTML5 table output from Web-book NIST.gov website
Nitrous oxide (N2O) vapor phase properties, HTML5 table output from Web-book NIST.gov website

The critical point of any pure fluid is where the distinction between gas and liquid phases disappears. This is not necessarily hazardous but it does mark a fundamental change in fluid behavior. The critical point of nitrous oxide (N2O) is 1053.3 psia and 97.6 degrees Fahrenheit according to Air Products company literature. This means the nitrous oxide conditions in the bottle at the launch (1400 psig as read on the gauges with an fluid temperature of 106 Fahrenheit or more) was well in the supercritical range, but again, this is only hazardous if the pressure vessels and plumbing connections aren’t able to safely contain the pressure. If the solenoid valve could have been opened, the pressure drop would have returned the supercritical fluid back to normal conitions and would flow dense liquid into the rocket when the fluid naturally chills down from the expansion.

Both the bottle pressure gauge and the manifold pressure gauge read excessively high on that hot summer day.

Keeping the bottle pressure below 1000 psia means controlling the external temperature of the bottle to a lower temperature. Below is a tabulation of state points along the vapor pressure curve for nitrous oxide (N2O) for common ambient temperatures. You can see that small shifts in ambient temperature can greatly affect the vapor pressure of the pressurized liquid. Keeping nitrous oxide under pressure is the key to retaining its denser liquid state. As long as the tank pressure is above the vapor pressure at that fluid temperature, you will have a liquid phase in the tank. If the pressure on the fluid drops below the vapor pressure, the liquid will begin to boil away.

  • 30 F, 440.05 psia
  • 40 F, 506.63 psia
  • 50 F, 580.33 psia
  • 60 F, 661.71 psia
  • 70 F, 751.46 psia; liquid density 48.21 lbm/ft3, vapor density 0.1145 lbm/ft3
  • 80 F, 850.46 psia
  • 90 F, 960.09 psia
  • 97.6 F, 1053.3 psia; density 28.22 lbm/ft3, CRITICAL POINT
  • Molecular weight = 44.01 lbm/lb-mol
Vapor curve for nitrous oxide over ambient temperature ranges

At first, it was thought that there wasn’t sufficient current from the lawnmower lead-acid battery we use. The summer heat can cause batteries to fail, but even after switching to a car battery, the failure to open was the same. Having a 12-volt solenoid requires greater current to actuate the solenoid valve, but it is a common standard for automotive grade parts which can be less expensive yet reliable. A current draw of 15 Amps over the long cable runs of a few hundred feet can be taxing to the firing circuit battery. This was not the cause of the problem, but it is a regular concern making sure sufficient voltage and current is available to both ignition and valve control.

To exclude outright failure of the solenoid valve, Osvaldo brought the unit home, allowed it to cool to room temperature then dry-cycled the valve from a battery to see if it still actuated. This simple test was successful and the filling valve in our nitrous oxide manifold continues to operate. At the next launch attempt, we will be prepared to chill the nitrous oxide supply bottle with an ice bath if necessary as was originally suggested at the prior launch event. Keeping the bottle pressure in an appropriate pressure range for fill operations is dependent on controlling the fluid temperature (60 to 90 F) under extreme heat or cold environments.

In researching purge solenoid valves, a second 12 VDC normally-closed valve was found and purchased. Nitrous Supply Inc., was out of purge solenoid valves but offered many alternative suppliers in the Los Angeles area. After some searching, I selected a high flow purge solenoid valve sold by Motorcycle Performance Specialties (MPS) Racing in Casselbury, Florida, for the purge solenoid valve used for venting our nitrous oxide manifold. The control panel is already equipped with the second command channel to open the vent from the blockhouse should it be necessary in launch operations. A schematic illustration is provided in this article.

mpsracing.com

Normally-closed 12 VDC purge solenoid valve from MPS Racing in Florida used for nitrous oxide applications including car and motorcycle racing.

The previous drain solenoid valve equipped with the nitrous manifold I bought was not deisgned for the full bottle pressure in the manifold so it quickly failed during initial checkouts. A manual valve was used in its place to carefully bleed out the remaining pressure in the line after the main bottle valve was tightly closed. This second solenoid valve will be used for draining the nitrous in the event of a launch scrub. Although the Contrails hybrid motor already has a small orifice and vent tube at the head end of the nitrous tank to provide slow release of pressure buildup, it is better to have a remote option to quickly depressurize the vehicle if the need arises.

Fill, drain and firing circuit for a Contrails hybrid rocket motor

With some re-plumbing of the nitrous oxide manifold to include the new vent solenoid, a soap-bubble leak check would be needed to prove the system before use. Given the significant overhanging weight of two solenoid valves, it may be wise to mount both valves on a separate plate structure to avoid excessive bending loads on the bottle connection. Design changes like this will be considered in preparation for the next launch event.

PYROTECHNIC OPERATOR TRAINING SESSION BY FRIENDS OF AMATEUR ROCKETRY

Mark Holthaus of the Friends of Amateur Rocketry (FAR) organization is offering an online training session for those interested in becoming licensed pyrotechnic operators in the state of California. The event requires registration on the FAR website and a fee paid to FAR ($10) to attend this two-hour introduction to the licensing and application process to be held on August 26th.

Friends of Amateur Rocketry website for indicating interest in pyro-op classes

Amateur rocketry in California is controlled by the same laws governing fireworks which require licensing by a state exam. The application forms and guidelines are available through the Office of the State Fire Marshal in the state of California (CALFIRE).

https://osfm.fire.ca.gov/divisions/fire-engineering-and-investigations/fireworks/

This training course for pyro-op applicants is another example of FAR and the RRS partnering to help the cause of amateur rocketry. The RRS, FAR and Rocketry Organization of California (ROC) last year met to create a joint set of recommendations to help CALFIRE improve the definitions used to govern amateur rocketry when CALFIRE they were seeking input from rocketry organizations. It is to the mutual benefit of the whole rocketry community and the public that there be more licensed pyro-op’s in amateur rocketry to both increase awareness of state laws and improve the culture of safety in our hobby and professions.

This FAR training course only serves to provide applicants with basic guidance on how to begin the application process and prepare to take the examination. Members of FAR, the RRS, ROC and any other amateur or model rocketry organization are welcome to apply. Several members of the RRS have already applied as the society continues its campaign to grow our ranks of licensed pyro-op’s at all three levels.

Completion of this training course does not substitute for any part of the pyro-op application process set by CALFIRE. As each applicant is required to pay their own fees including fingerprinting, they must also provide five letters of recommendation from licensed pyro-ops at or above the level of license being sought. After this class, each applicant must formally request these letters from state licensed pyro-ops in writing. For a licensed pyro-op to offer a letter of recommendation to an applicant, they must be willing to endorse their skills, knowledge and character to the state of California based on their personal experience with that individual. This is done through active participation at launch events through rocketry organizations having licensed pyro-ops leading their operations. Apprenticing, studying and attentiveness are all ways that a pyro-op can get to know an applicant personally and thus build confidence that the applicant is ready to have the responsibility of being licensed in rocketry. A letter of recommendation is given solely at the discretion of the licensed pyro-op which means their standards and expectations may vary significantly from others. It is important to establish a working relationship with both the society and the specific pyrotechnic operator over several projects to demonstrate skills and learn best practices through active participation.

As the RRS has more licensed pyro-ops than FAR at this time, this training course will be successful if both organizations support it. Some of the RRS pyro-ops have already offered their support as this means more people will need to become active with the RRS and conduct their projects at the MTA.

ROCKET LABORATORY AT THE COMPTON AIRPORT

Keith Yoerg announced that there is a tentative plan to create a rocket laboratory in a hangar at the Compton Airport, Although, the hangar will be used from time to time to store or service light aircraft, there is a great deal of working space which will help the RRS continue their liquid rocket project already underway. Several members of the RRS are also active with civil aviation and are members of Chapter 96 of the Experimental Aircraft Association (EAA 96). The EAA has generously supported the RRS over the last two years and we hope to continue and expand this partnership.

NEXT EVENT AT THE MOJAVE TEST AREA

The RRS has been planning the next event at the Mojave Test Area which will be dedicated to repairing some of our facilities including the adjustable rail launcher damaged in solid rocket launch explosion in August 2019. The consensus at the meeting was that we should not to return to the MTA for a formal launch event until the seasonal temperatures decrease from the excruciating desert summer. October 3rd was selected for this work event, Our hope is the weather will be cooler and we can accomplish more on that day. We may also take some time to search for more rockets planted downrange from past launch events.

The RRS may also conduct a few static firings or even a launch if member projects are ready. All such proposed hot-fire and launch activities must be proposed to the RRS president and the selected pyro-op in charge for that day. Some of our member projects such as Wolfram Blume’s Gas Guzzler two-stage ramjet and my second-build of the high-powered hybrid rocket are both still works in progress and may be ready for the early October launch date. Larry Hoffing has been working on an improved solid motor chemistry which he may want to test at the MTA.

The RRS is available for private events before that time, but one must make their request to the RRS president as usual. Some have indicated interest in returning to the site for just a few hours to recover more rockets downrange. Its our policy that at least two members be present for any excursions to the MTA and the RRS president must be notified in advance.

IN CLOSING

Some topics were not able to be covered including the overview of the new RRS Constitution as it gets ready for administrative membership review. Also, facility improvement plans at the RRS MTA including new restroom facilities and blockhouse should be discussed.

The next RRS meeting will be held by teleconference on September 11, 2020 as it is unlikely we will be permitted to return to the Ken Nakaoka Community Center by then. We hope everyone continues to stay safe during these days of the pandemic and try to stay in touch as we are planning another event at the MTA for October 3, 2020.

If there are any questions, please contact the RRS secretary.

secretary@rrs.org