MTA launch event, 2021-03-20

Dave Nordling, Reaction Research Society


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.

The Rockwell mobile trailer at the RRS MTA
The interior needs a little work but otherwise has a lot of promise.
A spacious interior which could be used as an office space.

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.

Keith Yoerg holds up the speaker after a successful test at the old blockhouse

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.

General placement of the proposed new restroom facility at the MTA subject to change and only for illustration..

FIRST FLIGHT OF THE SOLAR CAT FROM 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 Inman and his team set up his parabolic solar heating system for today’s sunny day at 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.

The Solar Cat gets a clean release from the launcher and clears the rails on 3/20/2021.
The Solar Cat reaches its apogee while still in the frame of the video recording.
The wind pushes the rocket back to the launcher for an ungraceful return then clonking to the ground.

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.

Osvaldo Tarditti and Bill Janczewski observe Wolfram Blume’s operations with his ramjet upper stage in our loading area. No gasoline will be used in the maiden flight which will test the booster and staging systems. The unique design will need some flight testing before committing to a full flight with a fueled upper stage,
Wolfram Blume walks to the launch pad where his Gas Guzzler rocket rests on the pad.

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.

Two 18-channel fire control boxes with the remote in the middle.

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.

wilsonfx.com

cobrafiringsystems.com

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 Contrails H222 motor reloaded for the third time.

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 vertical test stand holds the hybrid motor ready for firing with the fill line above and clear vent line below.
The 3/16” nylon fill line c0nnects to the floating injector push to connect fitting below the fuel grain and graphite nozzle held down by the snap-ring. The electric match is wrapped along side of and held against the fill line.
Acrylic 1/8” vent line from the top bulkhead push to connect fitting

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.

A thin piece of composite propellant pressed against the electric match head pressed against the nylon fill line.
Floating injector loaded with the igniter and fill line strung through the fuel grain and nozzle.
The hybrid firing box with ruggedized 100-foot cable

The new hybrid rocket firing box with built-in solenoid valve and fire control.

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.

Water rockets lift off from the new blockhouse.

MODEL ROCKETS

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.

The Estes Generoc E2X loaded with a C6-7 motor. An inexpensive and simple answer to the Yoerg Challenge,
Dmitri Timohovich built the Firestreak SST for the Yoerg Challenge
A few model rockets fly up and away at our arch.

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.

IN CONCLUSION

Next launch event will be April 10, 2021, with USC and member projects.


MTA launch event, 2021-02-20

by Dave Nordling, Reaction Research Society


The Reaction Research Society held another launch event at the Mojave Test Area (MTA) on February 20, 2021. The weather was not cooperative for much of this day with wind gusts well beyond acceptable limits for launch (> 25 MPH). Our neighbor, Dave Crisalli and his Polaris Propulsion team, were using the Dosa Building as he had construction activities planned but were cancelled for that day. The RRS and Polaris Propulsion were glad to share the Dosa Building as we both made good use of the day.

The three planned objectives (weather permitting) for this MTA launch event were:

  • Build a new pit toilet restroom just north of the original site.
  • Conduct Solar Cat operations at the MTA
  • Conduct model rocket launches from Keith Yoerg’s new wire launcher array

THE ALL-SOLAR POWERED SOLAR CAT PROJECT

Bill Inman and his colleague, John Wells, made the long journey to the MTA from Nevada. Bill had made further improvements to the launching system and solar collector powering the Solar Cat steam rocket. He was able to and a remote tracking motor and drive system to further automate his solar concentrator, but several minor problems in setup prevented a launch that day.

Bill Inman and John Wells examine and prepare the solar collector system from the trailer at the east side of our MTA.
Photovoltaic panel mounted to the front of the collector to power the tracker.
Bill Inman and John Wells set up the latest iteration of the Solar Cat steam rocket from just west of the alpha and beta launch rails

Bill is striving to use an entirely solar powered system including a photovoltaic power system for his auxiliary functions. Because of the east to west passage of the sun through the sky, the steam rocket must be launched in a northerly direction. This is possible if done from the northern or western edges of our launch site.

Although the winds were excessive throughout most of the day, Bill could still conduct some assembly testing and even conduct steam rocket heating operations while keeping the rocket secure on the ground. Launch would only be attempted if the winds lowered in that time. Sadly, much of the day passed in correcting minor problems and system tests. The system proved ready but insufficient sunlight remained that day and launch would have to be conducted from the MTA at the next opportunity.

BUILDING A NEW PIT TOILET AT THE MTA

The society has been examining many improvements to our Mojave Test Area which has stood for over 65 years. The site has been improved over the many years but time has taken its toll and renovations are needed.

The top priority selected by our membership and visitors was the restroom facilities. Our short term plan was to build a second pit toilet while we work on plans for a more luxurious option in the longer term. This effort is viewed as a stopgap solution which will serve our society for at least a few years. Dmitri Timohovich and Wilbur Owens contributed greatly to this effort. With the many people we had at the site, we were able to start and complete the project with time to spare that day.

Our starting point for the project.
Wilbur operates the backhoe to get the trench dug for the sonotube. While Dmitri completes the wooden deck for the new pit toilet,
The precarious job of installing the sonotube once the pit is at the proper depth.
After getting sonotube vertical, the rest of the pit was filled with a few bucket loads of dirt and a few of us with shovels.
The new restroom deck gets placed and aligned with the new sonotube.
The toilet booth is removed from the original concrete platform. Our president, Osvaldo Tarditti, pauses a moment to consider how much crap our society has taken from our visitors and members alike,
The toilet booth is placed on the new platform, but first some further trimming of the sonotube must be done,
RRS secretary, Keith Yoerg, and RRS member, Dave Nordling, stand at the original concrete platform now filled flush to the surface with dirt. The task is nearly complete.
Once firmly affixed to the new platform, the toilet booth was fit checked by Dmitri Timohovich. He is signalling that our pit toilet is now ready for business.

The pit toilet project was a success thanks to both our members providing their physical and material labor and the careful planning and coordination that took place starting in this new year. This improvement project will be only one of several to come. We hope to make our remote testing site both more functional but also a bit more comfortable to all who visit us after many hours drive from the city.

LAUNCHING ROCKETS FROM A NEW MULTI-WIRE RAIL STRUCTURE

With the last hours of the day upon us, the winds had subsided to a more reasonable speed. Keith Yoerg had a few model rockets prepared for launch with commercial motors. He had also built a multi-wire launcher which is a convenient way to display and launch several small vehicles successively.

Max Timohovich (left) views the Baby Bertha and the Big Bertha rockets as they sit on the launch rail made from PVC pipe and fittings.

Second thing introduced at this MTA launch event was a four channel launch box built by Dmitri Timohovich. With a clean wood finish and a rugged latched case, this box proved its function well with the launch of three model rockets that day.

The new launch box was tested at the 2/20.2021 MTA launch event

After some glitches with the electric matches, Keith was able to launch and recover the Baby Bertha (A8-3) and the Big Bertha (A8-3) rockets. We got excellent footage of these classic model rocket types. The last of the three launches was the slightly larger Star Orbiter (E16-6) which left the rails cleanly and the recovery system deployed without issue. Although the winds had subsided sufficiently at ground level, the higher level winds carried the Star Orbiter for a long horizontal trek west well beyond the property line, After some searching, the Star Orbiter was lost to the desert hoping to be recovered

Baby Bertha leaps off the wire rail with its tiny A8-3 motor,
Big Bertha comes back under its parachute landing just to my left. This great video can be seen on the RRS Instagram account.
The last photo of the Star Orbiter as it sits on the pad before the wind carried it far to the west.

IN CLOSING

The team cleaned up the area and put away the gear at sunset. We talked about setting the next launch date in March 2021. We hope to have a new date set soon, likely after March 12th.


MTA work event, 2020-10-03

by Dave Nordling, Reaction Research Society


The long awaited work event at the Reaction Resesrch Society’s private testing site, the Mojave Test Area (MTA) took place as planned on Saturday, October 3rd. We had a good turn-out to take on a few of the much needed repairs, cleaning and maintenance activities around the site. These work events not only improve the site but also enhance it’s appearance for our visiting guests. The RRS takes pride in our one-of-a-kind site and working on our site makes us all more closely connected as public activities are so few during these unprecedented times. All activities were able to maintain social distancing and everyone had their mask.

The primary purpose of this event was maintence activities but secondarily we were ready to conduct launches if members had projects ready. I was the pyro-op in charge for that day if there was to be any launches. Wolfram had cancelled his first flight attempt of the Gas Guzzler two-stage rocket due to concerns with excessive heat. Also, my next attempt to fly my nitrous-oxide hybrid rocket was postponed as we needed more people to work the planned maintenance events throughout that day. Bill Inman had contacted me with his proposed solar heater experiment. After a cursory review of his experiment, the society allowed him to proceed. Bill makes a very long journey to the MTA from Carson City, Nevada, and we are glad he has chosen the MTA to conduct his initial experiments for his next generation steam rocket.

Osvaldo led the repair and refurbishment efforts that day. Despite the higher peak temperatures that day, a lot of work was done which has helpful in restoring the site.

The arched sign welcomes our membership and guests to the RRS MTA. Still looking great after years in the desert.

REPAIR OF THE 8-INCH ADJUSTABLE BOX RAIL LAUNCHER

The 8-inch adjustable box-rail launcher was damaged in a failed solid motor launch last year at the MTA. The resulting explosion destroyed the four adjustable rail guides and distorted a few of the box frame members. Given the heavy and large size of this box rail launcher, it was only practical to conduct repairs at the site and bring in new steel materials to be cut, grinded and fitted for welding such that all parts fit correctly.

Getting ready to build new rails in the 8-inch adjustable rail launcher

The replacement rail guides used thick square stock instead of the previously used round stock. This was done for both having a flatter surface for clamping and holding the rails in place but it also made moving the rails easier to do than with the closer fitting round rails. The square slider pieces were also more easily welded to the square rails with much grinding.

Osvaldo and Dmitri did excellent work. With the right tools, material and skill, the job was done by mid-afternoon. The four rails are back in place, but some of the box rail members remain bent or distorted. Although not entirely perfect, the rail launcher should now be useful again for future tests,

John Krell (left) and Dmitri Timohovich (right) inspect the repairs on the 8-inch box rail launcher at the RRS MTA on 10/3/2020

TUMBLEWEED AND BRUSH REMOVAL

A lot of the team was working on clearing the immediate area of tumbleweeds near the many structures and sites around the MTA. Alastair Martin and Keith Yoerg worked many hours with a metal rake and shovel and made a marked difference around several overgrown spots. Tumbleweeds are a persistent nuisance throughout the western United States and Mexico as they thrive in the dry hot climate. Removing them is fairly easy, but disposing of them is far more challenging. Fire hazards are one of the topmost concerns in amateur rocketry. Our desert launch site is always under this threat. By periodic clearing and disposal, the threat of fire propagation can be minimized.

Clearing the east side of the container fenced area.
The large vertical test stand after some clearing efforts both on the ground and on the upper decks.
Second view of the large vertical test stand at the RRS MTA at the end of our 10/3/2020 work event.
Waldo drags an old iron launch platform to clear the vegetation from around the MTA site

Keith and Alastair did a lot of hard work in manually clearing the edges and the upper decks of the vertical test stand. Waldo Stakes was also kind enough to drag the area to clear wider spaces more quickly, The result is a clearer work area better able to conduct rocketry activities at the MTA.

CORROSION PREVENTION AND PAINTING

Frank Miuccio and Chris Lujan worked on the metal lattice covers on the two front windows of the Dosa Building. They sanded and brushed on rust remover to clear the surfaces for a protective paint coating, It was a lot of fine detailed work but the resulting look of the metal grates without rust looks so much better.

Frank carefully sands, treats and paints the metal lattice covering on the front windows of the George Dosa building at the 10/3/2020 MTA work event.
Chris Lujan steps back from his work on the other front window of the George Dosa building.

Little touch-ups can be very time-consuming but it is worth taking the time to do the job well. There are many areas around the MTA that could benefit from some corrosion removal and surface protection. Although the desert is dry, the caustic, salty, dry lake environment can erode steel surfaces over the years.

SOLAR CONCENTRATOR EXPERIMENT

RRS corresponding member, Bill Inman came out to the RRS MTA work event to conduct a test of his first prototype solar concentrator for heating his next generation steam rocket. The experiment was a simple apparatus design to focus sunlight on a length of 2-inch black-painted iron pipe holding roughly 2,7 liters of water.

The wooden box had two angled mirrors to focus most of the incident sunlight near the pipe. To avoid natural convection losses, his concentrator had a clear glass panel enclosure. In essence it is a trough heater. The goal was simply to understand the practical operation of this first device and make improvements to see if a solar-based heating scheme for a steam rocket is feasible. Bill’s device had approximate pressure relief should the concentrator over-perform.

Bill Inman’s first prototype solar trough collector for heating a steam rocket tested on 10/3/2020

Results were a little lower than expected, but a measurable gain in water temperature was measured after operating throughout that afternoon, Air temperatures reached a peak of 104 degrees Fahrenheit (F) and the peak water temperature was 180F, far short of boiling temperature (212F) at amibent pressure. Effective steam rocket temperatures are often around 350F to 400F. There is more work to be done.

A FEW SMALL ROCKETS LAUNCHED

Keith Yoerg prepares the Big Bertha for launch on his wire rail launcher.

Keith Yoerg had brought a few small rocket kits for launching at the MTA during a break in the maintenance work. A classic Big Bertha and Baby Bertha each with B6-4 motors. The winds were very light and good for launching these small rockets. Both were ably recovered.

IDEAS FOR FUTURE WORK AT THE MTA

Near the end of the day, we discussed new improvement tasks at the MTA. A few of these were listed below:

  • Further removal and disposal of tumbleweeds, there are a lot along the eastern fence and in the flame bucket of the large vertical thrust stand. Burning them under controlled conditions is one possibility but winds must be very low
  • More ideas for the new restroom facility were discussed that could take advantage of pre-existing materials or assets at the MTA
  • Removal and replacement of the bent steel panel on the vertical thrust stand. New steel panels were made with the matching hole pattern.
  • Rust removal, corrosion prevention and painting of the large vertical test stand structure is a lengthy project but would greatly improve the look of the whole site.
  • Removal and replacement of the old blockhouse roof and shoring up the existing walls is being considered as a lower cost upgrade to this important and often used asset at the MTA.
Taking some measurements around the bent panel on the vertical test stand at the RRS MTA

It was a great team effort that day and everyone worked very hard. Nearly all of the planned objectives were accomplished. It has been suggested that another work event at the MTA be planned for next month. We also hope to work in a few launches if we can.

These ideas and other topics will be discussed at the next meeting of the RRS on Friday, October 9th. We’ll hold this meeting by teleconference again due to COVID-19 restrictions. Those wishing to attend should contact the RRS secretary.

secretary@rrs.org