The Reaction Research Society held a launch and firing event to honor the memory of Richard Garcia. His wife, Jeannie Riddles, his brother, Russell, and his aunt and cousin were present to witness the events of that day at our Mojave Test Area. I served as the pyrotechnic operator in charge with Dimitri Timohovich and Leanna Lincoln serving as my apprentices for the several operations we conducted that day with our membership and invited guests. RRS president, Frank Miuccio, was also present for this important event.
The safety briefing was given to all in attendance at 11AM with special recognition given to our honored guests. The weather was very hot (105F) which is typical for early September, but under low winds and a few high clouds.
We had several very different projects that day with many of our members coming to demonstrate their current projects and some bringing new builds. RRS member Jerry Fuller and his daughter Charlotte were also present that day.
Dimitri and Leanna mixed a batch of micrograin from the new zinc stock and our existing sulfur supplies. Chase Lang had a standard alpha and Bill Nelson a standard beta for launch. Both conducted safe loading operations in the RRS loading area.
With everyone under cover and passing air and road checks, the launch of the alpha still showed some of the initial low thurst stalling during firing before exiting the launch rail and being recovered downrange. The beta fired but showed an even lesser performance not managing to generate enough thrust to even leave the launch rail. Both rockets were returned for examination. Most likely cause is excessive moisture absorption into the sulfur, but that is under debate. Clumpiness of the powdered oxidizer was noticed during the mixing operation but a propellant sample burn beforehand showed no problems. it was thought that the tumbling process would be sufficient to homogenize and dry it out. Sulfur is not expensive and the society may consider buying fresh stock and improving the storage conditions.
Fourth year UCLA graduate student, Nick Kuenning, and his advisor, Prof. Mitch Spearrin, were present with a few UCLA Rocket Project members to static fire their new portable rig at the MTA. The main objective was to demonstrate the new oxidizer tank they added and run a prior engine design to check out the whole system. The test also served to show just how far UCLA has come in the many years since the liquid rocket program began at UCLA. Richard Garcia was one of the first RRS members to help UCLA in their early days of the Rocket Project. I attended UCLA PDR’s and CDR’s with him. Nick was just a freshman at the time. It was very generous of the UCLA team to conduct this firing in Richard’s honor during the last of the summer quarter when few students were back from vacation. The crew of four ran a clean and steady full-duration burn of their ablative lined engine on an impinging ethanol and LOX injector used with prior success. The burn went a full duration of 20 seconds with clean startup and shutdown. It is a very nice static fire rig and will give the team many opportunities to continue developing better engines. Nick is planning to speak at the RRS monthly meeting to share their results.
Mike Kramer and John Tsohas came to the RRS MTA as guests. Mike and John fired a few hybrid rockets that day and later joined as members. John had fired with the RRS several years ago and it was good to welcome him back. They had several successful launches and recoveries with the nitrous oxide loading and firing rig they brought.
Bill Inman brought the latest version of the Solar Cat which he and RRS member Dale Talcott built. The Solar Cat is a steam rocket mobile launcher that uses a parabolic reflector type of solar furnace for heating. It is an impressive piece of engineering with the ability to track the sun’s position in the sky and reach steam pressures up to 465 psig before moving the rocket tube into a vertical firing position. It is operated remotely and uses common off the shelf hardware.
After some considerable setup period the day prior in the northern expanse of the MTA, sun conditions that day were inconsistent however after 3:30pm a break in the clouds allowed a one hour period of insolation sufficient to reach adequate steam pressure for launch. Launch ended up not occurring as there was a mechanical snagging problem with one of the harnesses impeding the movement of the release mechanism.
Bill made the decision to abort the launch and remotely opened the vent to relieve the system dumping the load in a safe direction. Minor improvements will be made to the design to prevent similar issues and help avoid problems in deployment and stowing on the trailer. The Solar Cat design has advanced much and has had a few successful firings in Nevada. With Dale and Bill’s continued perserverence, the Solar Cat will one day fire from the MTA. It is a very long drive from Carson City, but Bill’s dedication to that test is a true honor to Richard Garcia and the passion he had for amateur and professional rocketry.
The RRS would like to thank our guests, our visitors and especially our membership for making this event possible.
The launch events will be discussed at the monthly meeting on Friday, September 13th, at 7:30pm at the front office of the Compton/Woodley Airport. RRS meetings are always on the 2nd Friday of each month. Contact the RRS secretary for details.
The Reaction Research Society held its last launch event of the year 2021 at the Mojave Test Area on Friday, December 17th. I was the pyrotechnic operator in charge. This was my first launch event as a Class 1 pyrotechnic operator although none of the activities this day involved a liquid rocket. We had four launches planned for that day. Two from Keith Yoerg, one from Wolfram Blume and one from Dimitri Timohovich. RRS members Wilbur Owens, Xavier Marshall and Bill Inman came to be spectators at this launch event.
Bill Inman at the RRS MTA on 12-17-2021
IMPROVEMENTS TO THE 1515 RAIL LAUNCHER
The first flight of the Hawk in late November revealed a concern about the stability of the 1515 rail launcher with heavier rockets. Although quite heavy in its steel rectangular tube construction, Dimitri and Keith used cinder blocks and sandbags to weigh down the legs of the base. This resulted in damage to several of the sandbags from the exhaust of the M-sized motor from the initial flight.
Flat steel plate with welded boltFlat steel plate added to the 1515 launch rail base for greater anchorage
A flat steel plate with a threaded rod welded to the center was connected to the bottom of the 1515 rail launcher to allow for more weight to the base and allow for more cinder blocks to be added for even more stability. New adjustable feet were added to the existing four threaded holes at the far points of the legs. Eyebolts were also bought to screw into the 3/4-10 holes in the pad to strap the base down if necessary.
The 1515 rail launcher with its new anchor plate held down by cinder blocks.
SECOND FLIGHT OF THE HAWK
The December 17th launch event was primarily for the second flight of Keith Yoerg’s massive 14-foot long, 8-inch diameter Jumbo Dark Star rocket made by Wildman Rocketry with a 98mm Cesaroni N2600 Skidmark motor. The launch was held on Friday to coincide with the anniversary of the Wright Brothers first flight..
The payload tube of the Hawk being prepared for launch on 12/17/2021.
The payload was something very special to the Yoerg family and to American aviation history. The payload was a few squares of cotton fabric from the right wing of the original Wright Flyer aircraft that made aviation history. This cloth was the actual material that flew in 1903.
An authenticated piece of American aviation history flies on the Hawk from the RRS MTA.
A similar piece of the cotton fabric used in the Wright Flyer was sent with the Mars Ingenuity helicopter aboard the Mars 2020 mission being part of the first aircraft flown on a foreign world.
Mars Ingenuity helicopter at Jezero Crater on the surface of the Red Planet in April 2021
It was amazing to fly a similar piece of history at our humble launch site for our members to enjoy on the anniversary of manned flight.
After securing the payload and verifying the recovery systems were in proper working order, the Hawk was taken to the launch pad and erected for flight.
The Hawk slid into the 1515 extrusion rail by its rail buttons.Manually erecting the Hawk took several people to carefully raise and push the stopping pin once the rail was near vertical.Keith checking out the wireless data system.Dimitri connects the igniter circuit into the society’s new Cobra wireless firing system Keith Yoerg and Xavier Marshall of the RRS pose with the Hawk before its second flight on the Wright Brothers anniversary.
Before the countdown, Keith gave a very moving speech with his mother, Janette Davis, present in the observation bunker.
118 years ago today, on the sandy windswept dunes of Kitty Hawk, North Carolina, my Great-Great Granduncles Orville and Wilbur Wright achieved the first powered, heavier-than-air flight of a manned aircraft. A few small pieces of fabric from that historic airplane are ready to take flight again today, from the sands of the Mojave Desert, aboard ”The Hawk” an 8-inch diameter 14-foot fall rocket Honoring Aviation, the Wrights, and Kinetics. In 1903, this fabric reached a max altitude of 10 feet at a max speed of 10 feet per second. Today, that same fabric is expected to reach an altitude of over 7,000 feet with a max speed of 791 feet per second (or Mach 0.7).
We’re now ready to start the countdown.The sky is clear, the road is clear.
Flight 2 of “The Hawk” is launching in 5… 4… 3… 2… 1…
Rail-mounted camera caught a few frames before the N-motor destroyed the lens.
The second flight of the Hawk was close to predictions reaching over 7,800 feet in altitude and 742 feet per second. The Hawk with its drogue and main parachutes working properly was fully recovered. Keith got telemetry data and provided screenshots of the results below.
Telemetry data from the second flight of the Hawk on 12-17-2021
Beckie Timohovich was a big help in the recovery efforts and bringing back the hardware to the launch site. She also makes really good Alaskan caribou chili which we all got to enjoy at lunch in the Dosa Building.
The ratcheting extraction tool for removing alphas from the ground.The Hawk returned safely to the ground with the historical payload intact. Wireless and onboard data was recorded and video footage from the ground and on the vehicle was recorded.
The 1515 rail launcher with its heavier base worked well and did not shift although the straps were singed by the hot exhaust and seemed to be superfluous. The parachute system on the Hawk deployed well and brought the vehicle down in tact. Most importantly, the family heirloom flown as a payload was returned to safekeeping.
The 1515 rail after launching the Hawk. Unfazed and ready for another pounding from Wolfram’s K-sized booster motor
Keith is considering his next flight of the Hawk. One idea is to fly an even larger motor if an O-sized motor will fit in the existing 98mm mount. The goal being to go faster and break the speed of sound and fly even higher. Keith was also pondering adding a second stage to the Hawk. We hope to learn his next plan in the new year as we hope to have another launch event in January 2022.
TWO MICROGRAIN ALPHA ROCKETS
We flew two alpha micrograin rockets. One by Keith Yoerg, one by Dimitri Timohovich. Each had a payload built by John Krell. These were the first zinc-sulfur rockets to be loaded and flown by Keith and Dimitri which although both them have been active members of the society for years, this experience served to initiate them into the RRS.
Dimitri was first to load his blue nose-to-red finned rocket and fire it while Wolfram Blume completed his assembly and preparations for the second flight of the Gas Guzzler two-stage rocket with a water ballasted ramjet upper stage. Keith Yoerg’s alpha with the bright pink nosecone and fins was the second of two alpha flights, Like with the Hawk before it, the RRS used our Cobra wireless firing system with the alpha rockets.
Dimitri Timohovich loads the powdered micrograin into the propellant tube using gentle vibration to release any air pockets.Keith finished with the loading of powdered propellant, installs the nozzle into his alpha.
Keith edited the footage of both alpha flights into one compilation on YouTube. See link below:
John Krell’s Adalogger design custom built for the tight confines and high acceleration of Keith’s RRS standard alpha.Keith prepares to load his alpha into the box rails.Still capture of Keith’s alpha streaking nearly straight up in nearly calm winds that day.Keith Yoerg’s first alpha rocket.
A few days after the MTA launch event, John reported a summary of the results from the two different instrumentation payloads. His emails are paraphrased below.
On 12/17/2021, two Alpha rockets were launched. Both were instrumented with high speed flight computers. Dmitri’s Alpha (blue nosecone) carried an original Alpha Datalogger on it’s third flight and Keith’s Alpha (pink nosecone) carried a newer Adalogger design on it’s second flight.
John Krell had two data logger designs. the original data logger design was flown on Dimitri’s alpha.
The bad news first. The Adalogger SD card socket broke during its first launch. I did not catch this issue prior to this launch. The SD card fell out of its socket during the initial acceleration and no flight data was recorded from Keith’s alpha, The next design update will include a nylon post to prevent SD card ejection. Keith’s Alpha also incorporated a semi-soft shock absorption mounting. It didn’t work as well as planned, but it does show potential with two modifications. Damage to the Adalogger system was minimal and repairable.
9-volt battery mounted in the aluminum nosecone of Dimitri’s RRS alpha.
Dmitri’s Alpha produced significant new data during the burn for a micrograin rocket. The thrust was relatively smooth and constant compared to the previous three Alpha launches that carried flight computers and returned data. Absent were the large acceleration bursts during the burn. (See attached graph)
Acceleration plot of Dimitri’s alpha flight.
Also recorded was the impact. The impact duration was measured at 16 milliseconds. This is the shortest impact duration recorded for an Alpha. A prior impact duration of 18 milliseconds produced a deceleration of 716 G’s. This impact deceleration should exceed that value.
Further analysis of the data is required to determine a value. A picture of Dmitri’s rocket in the ground prior to extraction will be helpful. (Photo was later provided.)
Motor burn duration 0.408 seconds
Maximum Acceleration 103.95 G’s at 0.304 seconds
Maximum Velocity 676 ft/sec, Mach 0.6 based on integrated accelerometer readings
Altitude at Burnout ~138 ft
Maximum Altitude 4,307 ft AGL by barometric readings
Terminal Velocity 463 ft/sec, Mach 0.411 based on barometric readings
My video records of Keith’s Alpha show a shorter burn duration equating to a higher acceleration and velocity. The altitude should also be higher with the shorter down range distance.
Dimitri’s alpha with its red paint at the aft body coming off from the intense heat of the micrograin burn. Dimitri’s rocket was found significantly further downrange than Keith’s but on the same heading
The still pictures at the end furnished the information necessary to estimate the deceleration at impact. Keith’s alpha’s penetration depth of approximately 3 feet 10 inches correlates to a deceleration rate of 680 to 720 G’s in a span of 18 to 20 milliseconds. Dimitri’s Alpha penetrated approximately 3 ft 8 inches into the ground in 16 milliseconds equating to ~900 G deceleration rate. Wow!!!
The main objective was to give all of our active members experience with micrograin rocketry. Although rarely practiced outside of the society, it is considered to be something of a rite of passage and also serves as valid experience with the unlimited category of rocketry. This event gave Dimitri and Keith this experience which will help them as they advance as pyrotechnic operators.
SECOND FLIGHT OF THE GAS GUZZLER RAMJET
Wolfram Blume brought his second build of the Gas Guzzler rocket to the MTA for a December test flight. The same booster section with an Aerotech K-motor was flown. The ramjet was rebuilt and was flying a 3/4 load of water in the gasoline tank to have a representative payload weight including any possible sloshing that might occur.
Wilbur Owens discusses the ramjet operation with Wolfram Blume. This forward view is without the forward cowl. In the background is a graduated cylinder for precisely metering the fuel load into the ramjet.The forward end of the ramjet with its annular cowl and forward spike as it nears final assembly.The Gas Guzzler booster stage design remained the same for this second flight from the MTA.Wolfram holds the lower half of his ramjet ready for final assembly and stacking of the two stages.Wolfram carefully walked the ramjet upper stage to mate with the booster stage already on the launch rail.Wolfram Blume and John Krell examine the Gas Guzzler on the 1515 launch rail before its second flight.The Gas Guzzler sits side-saddled in the 1515 rail launcher to allow proper clearance of the fins.The Gas Guzzler lept straight and clean from the 1515 rails in its booster flight.
From the ground, it was clear that the booster flew straight and stage separation had taken place. The booster parachute ripped loose. The ramjet came down only under its drogue chute and the hard landing damaged the upper stage enough to warrant a complete rebuild.
Clean stage separation was evident, but the booster parachute ripped loose.
Wolfram spent several days after the launch event looking at the remains of Gas Guzzler. A few things are known so far:
The addition of 1.14 kilograms of ballast water did not cause any problems. The two stages – both separately and together – were still stable in flight. Also the stage separation worked.
After separation, the booster came apart at apogee into two pieces. It is an easy fix as a bulkhead blew out and only needs to be better reinforced against the loads. A recent addition of a GPS tracker to the second flight of the booster worked.
The ramjet lost electrical power at apogee. The reason was found and will be repaired. The power failure meant that the GPS tracking stopped at apogee which is a serious problem. Wolfram is considering adding a backup GPS tracker to the ramjet with a separate power supply.
Based on telemetry, the deceleration seen after stage separation gave the drag coefficient (Cd) on the ramjet at 0.25. The accuracy of this calculation is about 10% based on the acceleration readings which is fairly good all things considered.
drag force = Cd * velocity-squared * air-density
The thrust also scales with the square of velocity and that gives the minimum velocity when thrust minus drag exceeds weight to be about 656 feet per second (200 m/sec). This is the minimum velocity which the booster must supply at burnout.
For this flight using the K-motor in the booster, with the water ballast, the maximum velocity was 574 feet per second (175 m/sec). The ramjet reached an apogee of 3,800 feet AGL (above ground level). The booster pushing the ramjet reached an apogee of 3,100 feet AGL. Maximum acceleration under boost phase was 6 G’s. The ramjet was flown without fuel, only an equivalent weight of water instead of gasoline.
The next build of the Gas Guzzler will have a larger booster which will hold an L-sized motor.
In the 12-17-2021 flight, the ramjet’s drogue parachute deployed correctly but the main chute did not. This seems to have been caused by the drogue chute being too small. Rockets with dual-deployment parachute recovery systems typically split the rocket in two places with the drogue ejecting forward and the main ejecting backwards. It is a good, reliable system but it cannot be used in the Gas Guzzler design because you cannot split the ramjet in the middle. Both of the parachutes must deploy from the front. The recovery system design requires the drogue to pull the main out of the ramjet at 1,000 feet. Wolfram developed this system on prior rocket with launches at ROC in Lucerne Valley and it has worked the last three launches. Wolfram is confident that it will work in the next flight of the ramjet, too.
Damaged fragments of the ramjet recovered downrange after the second launch of the Gas Guzzler.
The air flow measured inside the ramjet during the second flight on 12-17-2021 was within the range of an air blower system at Wolfram’s workshop that had considered using to static fire the ramjet with an operational burner. However, he is not comfortable with trying the main burner at his workshop, but testing the flameholder and its igniter is OK. Thus, a static test of a fueled ramjet coupled with an air blower system is being considered.
Going forward, once the ramjet is rebuilt, Wolfram would like to verify the performance of the igniter and flameholder over the full range of the air blower’s speeds in a static fire setup at the MTA. In this testing, he also wants to work on how quickly the flameholder ignites to avoid losing a lot of forward speed after stage separation.
Wolfram will rebuild the ramjet as quickly as possible and could be ready for another launch in February 2022. He would like to do another booster-only flight from the MTA to verify the fixes on that stage. If successful, then the next launch will try a flight with a short ramjet burn using roughly 5 seconds of gasoline fuel.
The society will peer-review the work done so far and find the best way to proceed. Wolfram is still evaluating the data and may have an update to this firing report later.
TESTING OF A GERB AS A LIQUID ROCKET ENGINE IGNITER
Dimitri and I have overseen a few recent liquid rocket engine static fires at the RRS MTA. Although there have not been any ignition problems, we had discussed different approaches to getting a safe and reliable start.
Liquid rocket engines sometimes have problems with achieving reliable ignition. Failure to ignite the cold mixture of propellants due to lack of sufficient energy or outright failure to light can create a serious fire or explosion hazard. One of the simplest approaches is to use a sufficiently energetic pyrotechnic device mounted in the engine throat from the aft side. Visible indication of the igniter firing should be confirmed prior to opening the propellant valves and releasing the stored pressurant gas.
There are a few different pyrotechnic devices that are good for this task such as lances and gerbs. Both require a special license to get. Dimitri, who has such a license and happened to have a couple gerbs that we could try. Lances have been used in prior liquid rocket engine firings and vehicle launches with success.
At this event, we decided to test a gerb to see if it would be appropriate to try in lighting a liquid rocket engine. We secured one to the top of the alpha box rail and fired it to examine the plume,
A gerb is a pyrotechnic device used in firework displays.Simple schematic of a liquid bipropellant rocket engine with an external igniter systemThe gerb was fired to determine if it would make a suitable igniter for a liquid rocket engine.
Our impression of the gerb operation was favorable in terms of its 20-second firing duration, but it seemed that a smaller gerb size might be sufficient. Smaller gerb sizes are available. There is also the long-term consideration of having these available for liquid rocket testing which would require a storage magazine. Other less complicated means should be explored.
IN CLOSING
Several of the attendees stayed behind to clean up the MTA and relax in the Dosa Building. This was the last launch event for our outgoing president, Osvaldo Tarditti, who has faithfully served the society for many years with his time, skills and leadership. We enjoyed the sunset on a mild and nearly calm winded day. It was a fine end to a great day at the MTA and what was our last event of 2021.
The society held a launch event at the Mojave Test Area on June 19th. With many people having other plans, we were sparsely attended but able to get a few things done. The winds were very low and sun was very hot that day (105 F) making it a challenge to operate at the site, but with each other’s help we managed. I was the pyrotechnic operator in charge that day. I had intended to bring my hybrid rocket for this event but wasn’t able to complete the rocket in time. It would be Bill Inman’s Solar Cat, a pair of micrograin alphas and witnessing the UCLA Prometheus team launch their hybrid rocket after getting a replacement nozzle from the motor supplier.
UCLA Prometheus team posing before bringing their hybrid rocket to the launch rail at FAR.
BILL INMAN’S SOLAR CAT
Bill Inman and Jon Wells made the journey from Nevada to demonstrate a new sun tracking system improvement to better automate the solar heating process with the parabolic mirror. Unfortunately, there were several problems with the installation that ultimately went unresolved for that day. A series of benchtop tests would be needed before bringing his combined solar collector and rail launcher back to the MTA for a launch.
Bill had also expressed concerns about vibration from over-the-road travel taking its toll on the structure. He was already considering a major rebuild of his parabolic collector with a wider aperture. The next iteration of the Solar Cat is also supposed to be larger in diameter and capacity. With the Solar Cat work at a halt, Bill and Jon came over to assist Manny Marquez and myself with the loading of a pair of RRS standard alphas.
A PAIR OF ALPHAS
Osvaldo Tarditti was unable to attend this event, but he did measure out the zinc and sulfur in separate pre-weighed bags and provided a clean pair of alpha parts complete with the nozzles and well-painted, turned and recovered aluminum nosecones. For our new members, the society likes to give the experience of micrograin rocketry. Manny, Bill and Jon would have their first experience loading and firing an alpha that day. The society hasn’t launched many micrograin rockets since before the pandemic.
Manny Marquez loads the pre-weighed charges of zinc and sulfur powders before closing up the mixing barrel.With the generator powering the electric motor driven roller, the drum sits and gently rolls mixing the zinc and sulfur to a consistent mixture.
Manny was a big help getting the equipment out and running. I was able to train him in the old RRS tradition of micrograin rocketry. With only two rockets, we gave the loading duties to Bill and Jon. For their handling of the dirty task of slowly loading the propellant tubes, they each got the honor of finishing the build and preparing for launch.
New member, Jon Wells (left) and returning member, Bill Inman (right) hold the first of two loaded alpha propellant tubes.Bill Inman doing the hook-up under oppressive heat.
I was able to teach Bill, Jon and Manny the safe procedure for hooking up back to the control box in the blockhouse. With a well rehearsed procedure including air-and-road checks, we notified FAR in advance of firing our two alphas for that day to prevent anyone from wandering downrange before we fired.
Still capture from the launch of Bill Inman’s alpha; fast as hell
We each got a good lesson in the value of teamwork and a renewed respect for the heat of summer. The micrograin rocket is a simple but powerful initiation into experimental rocketry.
We all brought a lot of ice and drinks for that day and it was a big help.
Our next event has not been scheduled but we do plan to return to the MTA in July 2021. For members interested in planning the next event at the MTA, contact the RRS president and the executive council.
