A Tribute to Mr. George Dosa

by David Crisalli, Reaction Research Society


Some time in October of 1966, I had hitched a ride and gone down to an RRS meeting in Gardena. I was 13 and still in the 8th grade. At that meeting, I met Mr. Dosa for the first time. I met several other RRS members that evening, but Mr. Dosa was the most memorable. He was warmly welcoming, very enthusiastic about rocketry as a field of study, and also excited about having new students like me join the Society. 

As I attended more meetings and began to get involved in designing and building rockets, Mr. Dosa was always ready to offer help of all kinds from the loan of technical documents to the manufacturing of parts on the lathe and other tools he had in his garage. I spent many an enjoyable hour with him making steel nozzles, aluminum adapters, and fiberglass nose cones.

At one particular meeting in 1967, Mr. Richard Butterfield showed a 16 mm film of a hydrogen peroxide liquid mono-propellant rocket built and launched by RRS members David Elliot and Lee Rosenthal some 15 years before. I was completely captivated as I watched the two high school students in the film machine parts, fabricate sheet metal components, static test a liquid rocket motor in Mint Canyon, and then successfully launch the rocket in the Mojave Desert. Mr. Dosa saw my interest and enthusiasm and talked to me at some length about liquid rockets after the film. Then he asked if I would like to see the one he was working on. I jumped at the chance. 

The RRS meetings in those years were held in an old, small, wooden building on an isolated piece of property owned by a division of Pratt & Whitney in Gardena. It was really a shed but the RRS had been given permission to hold its monthly evening meetings there and store some of its equipment there. On the same piece of property, some 50 or so feet away, was a slightly larger wooden structure. Although larger, it was more of an empty garage and was not as suitable for meetings as the smaller building. When I told Mr. Dosa I would love to see the liquid rocket he was working on, he led me out of the meeting building and across the dark space between the buildings. It was probable nearly 10 PM by this time and there were no lights in the areas around either building. 

As Mr. Dosa opened the door into the very dark second building, he told me to wait there until he could turn on the light. “The light” was a single low wattage bulb hanging on a wire from the high ceiling. When the light came on, even in that dim glow from a single bulb, what I saw took my breath away. There, lying horizontally on a plywood table, was a bi-propellant liquid fueled rocket with the upper half of the skin removed. All of the tanks, plumbing, bulkheads, stringers, and longerons were precisely made and beautifully assembled. The rocket was more than 15 feet long and about eight inches in diameter. It was designed, Mr. Dosa explained, to run on 90% hydrogen peroxide and ethyl alcohol. I marveled as each piece of the structure and propellant plumbing was explained to me. The design was also unique in that Mr. Dosa had made the fuselage octagonal rather than round. This left him “corners” inside the rocket skin that he had used to run plumbing and wiring. The beautifully made fiberglass nose cone and boat tail were both round and the structure smoothly transitioned from octagonal to round at both ends. Mr. Dosa, a master at many fabrication techniques, had fashioned incredibly precise sheet aluminum sections that perfectly mated with the octagonal structure on one end and the perfectly round nose and boat tail on the other.

I could have stayed and talked to Mr. Dosa for hours, but it was very late now and my ride was leaving. Needless to say, I was completely stunned by what I had seen that evening and over the next several months and years, I must have made quite a pest of myself often keeping Mr. Dosa on the phone for long periods asking questions and listening to his patient explanations. From our first meeting in 1966 until I left for the Naval Academy in 1972, I met and worked with Mr. Dosa at RRS meetings and at rocket firings in the desert many, many times. Each and every time, it was a great joy to see him, talk to him, and learn from him. 

When I left for the Navy in the summer of 1972, “George” as he now had me call him, told me that he had been in the U.S. Navy during World War 2. He had met his lovely wife, Ann, overseas and brought her back home after the war. He wished me the best of luck in the Navy and asked me to stop by and see him whenever I got back to southern California.

After being gone for 18 years, I did find my way back to an RRS meeting and renewed my old acquaintance with George. In the intervening almost two decades, he had changed very little and was still as welcoming, enthusiastic, and as patient an instructor as ever. In the early 1990’s, I volunteered to restart publication of the long dormant RRS News. George was more than a little excited as he was always a huge proponent of documenting all of the projects that RRS members undertook. We began a very enjoyable and several year collaboration writing, editing, and publishing the RRS News more or less, once a quarter. 

During that same time frame, a few members of the RRS and I had started teaching a solid propellant class. As part of that class, several of us had written a course handbook. At the beginning of that course book, Niels Anderson and I had written a dedication to George because of his long, tireless mentoring of so many students and RRS members over the years. I include it here because I believe it captures the essence of who George was within the Society…


“Since the days of Dr. Robert Goddard, the United States has always had its share of rocket enthusiasts and experimentalists. In 1943, even before the end of the Second World War, the young students who founded the Reaction Research Society were hard at work experimenting with propulsion systems. As the “Space Age” dawned, the imaginations of millions were fired with the possibility of flight beyond the atmosphere of Earth. But to members of the many amateur rocketry groups forming during those days, flights of the imagination were not enough. Those with the interest, drive, and courage to try, designed and built fantastic rockets that exploded out of their launch towers on towering pillars of fire and smoke. These were not cardboard models with minuscule motors producing ounces of thrust. These were thundering metal machines, many feet long, producing thousands of pounds of thrust, and flying into the clear desert skies at unbelievable speeds. 

It was a great time of advancement, adventure, and experimentation. Some of those who built these great, unforgiving machines also became the mentors for hundreds of others who followed. These special few not only pursued their own projects, but stopped to share what they had learned with others. Guiding, advising, encouraging, they were tireless in their belief that there was much to be learned in the pursuit of amateur rocketry and they helped all who came and asked. Amateur rocketry, as a whole, owes a debt of gratitude to the few who trained and directed those of us too young and full of wild enthusiasm for our own good. They taught us many things, fed our enthusiasm for learning, encouraged us through failures, and kept us safe all the while with their knowledge and experience. 

This course is dedicated to one such man, Mr. George Dosa. George has been an active rocket propulsion experimentalist for many years. In many ways, he can truly be considered one of the founding fathers of experimental rocketry. George Dosa was the state of California’s first licensed solid propellant rocket pyrotechnic operator. He has been the back-bone of the Reaction Research Society for the last 38 years and still serves today as the Director of Research for the RRS. 

George has dedicated his life to the continuance, advancement and testing of experimental rocket propulsion systems. He represents the very essence of the golden years of experimental rocketry and has crusaded to preserve the right of new experimenters to follow this fascinating and technical hobby. Giving generously of his own time, he has contributed greatly to the education and encouragement of others. As a consequence, the Reaction Research Society would like to thank George by dedicating this first in a series of amateur rocketry propulsion classes to him personally and to his efforts in behalf of amateur rocketry over the years. ” 

Niels Anderson and David Crisalli, March 1996


George told me once that he had been born 30 years too early…he would have liked to have been that much younger when the age of rocketry began to blossom in the 1950’s and 1960’s. From my standpoint, George was born at exactly the right time. Had he been born later, we might not have met and worked together as we did. George lived for nearly a century and all through that time he was a kind, patient, and enthusiastic teacher, a gentle man with dreams of exploring the heavens. I will miss him greatly and I will say farewell (for now) with an old nautical expression….I wish you fair winds and a following sea, George. In a twinkling of God’s eye, we will meet again.

Most sincerely, 

David E. Crisalli, August 2019


David Crisalli is a lifetime member and former President of the RRS. He also is the owner of Polaris, Inc. in Simi Valley, California, a rocket propulsion testing and consulting company.

October 2018 meeting

The RRS met for our monthly meeting on Friday, October 12, 2018, at the Ken Nakaoka Community Center in Gardena. As usual, we got started by calling the meeting to order and reading the treasury report. We had a big agenda but covered most of the topics.

[X1]
Richard Garcia wasn’t able to join us at the October meeting. He wanted to report that he has made some design improvements to the RRS standard liquid rocket. He’s finished upgrading his engine design code to be able to analyze a blowdown engine (pressure-fed from the tanks). He also will soon have drawings for a thrust chamber design.

With some luck, I hope he’ll be back into testing at the MTA sometime soon next year.

[X2]
Electro Tech Machining (ETM) in Long Beach, California, specializes in graphite stock, graphite parts and Electrical Discharge Machining (EDM). They are experts and have been a loyal supporter of amateur rocketry groups such as UCLA and USC. The Reaction Research Society is happy to endorse them as they have been a great support to our society member’s projects as well.

Electro Tech Machining – Long Beach, contact information

Contact Cathy Braunsdorf at Electro Tech Machining.

Electro Tech Machining
2000 W. Gaylord Avenue
Long Beach, CA, 90813
(562) 436-9281

Electro Tech Machining in Long Beach, the graphite specialists

Electrical Discharge Machining (EDM) – Wikipedia article

I stopped in this week to pick up some round stock for making more graphite nozzle pucks for the ballastic evaluation motor (BEM) that is nearing completion. Graphite makes an excellent high temperature material for nozzle throats or any low ablation surfaces. We have used graphite inserts into reclaimed alpha and beta nozzles over the years at the RRS. Our society members have used graphite throats in their larger solid motor tested at the RRS MTA back in June 2018.

Plastic nozzle puck used for scale against the graphite round stock acquired by the RRS from Electro Tech Machining in Long Beach, CA

Moving into the meeting agenda, we shifted the order a little, but I have kept the numbering the same:

[1]
The latest educational event at Weigand Elementary school in Watts is going very well. The LAPD CSP program continues to help sponsor the event and we get great excitement from the kids. This Friday was the fifth of six educational events where they get to assemble the empty rockets. Osvaldo, Larry and Frank were on hand to help with the build process. The kids are really enjoying the process of learning and painting the team rockets will done in the last session before going out to launch at the RRS’s private testing site, the Mojave Test Area (MTA).

Two of our young participants show their assembled RRS alpha rocket at Weigand Elementary, Frank Miuccio in the background at the right

[2]
The next launch event at the RRS MTA will be the final step in the RRS’s educational program for Weigand Elementary school. We have this scheduled for October 27th and we hope to have cooler weather than in prior events now that the summer has passed. We have nine alphas from Weigand Elementary and three more alphas from our new membership, Wilbur Owens, Xavier Marshall and Michael Lunny.

Xavier Marshall looks over his first RRS alpha, welcome to the club!

[3]
I gave my quarterly briefing on the SuperDosa project at the October meeting. This time, I organized my thoughts and ideas into a presentation to give the RRS a general overview of the project and where we are so far.

Largely, I wanted to reiterate the project’s overall goals to many of the new members who have joined the RRS since the project’s inception in January 2017. The RRS intends to retake the amateur rocketry altitude record and in the process reopen our ability to make larger solid rocket motors and expand our reach both in our own community and literally with payloads ultimately flying above the atmosphere.

SuperDosa quarterly report, Oct-2018

I also acknowledged the recent progress of some of our new members formerly of the Chaminade Rocketry Club. Also, USC had a launch attempt with their Traveller III rocket, part of their Spaceshot Initiative. Unfortunately, instrumentation was not functioning but the flight looked to be nearly perfect. I hope USC will come present their recent accomplishments at a future RRS meeting.

Materials acquisition and some discussion about how to proceed with the propellant burn rate testing were the highlights of the discussion. More progress needs to be made in a few areas for completing the first prototype:

(a) Complete the design of all parts for the first prototype (6-inch booster)

(b) Begin prototyping instrumented dart payloads to practice flying and recovering these while getting good data. Making these devices work under the tight and unforgiving conditions that they must.

(c) More work in parachute recovery

(d) Estimating friction heat loads and heat mitigation strategies for the payload

Much of this prototyping work can be done at the MTA by flying smaller subscale vehicles and testing subsystems to prove they can work. More importantly, these tests give the society practice for the large vehicle testing which will reclaim the altitude record for the RRS.

The response to the SuperDosa project’s progress was very constructive and many new ideas were offered. I’m thankful to Frank, Steve Majdali, Larry, Osvaldo, Bill Behenna, Drew and Xavier for their inputs. I have taken notes and given actions to other members who are willing to help advance key areas of the project. Unfortunately, this topic was to be the last of the evening as my presentation easily exceeded the 20 minutes I intended.

The next quarterly report for the SuperDosa project will be January 11, 2019, and I hope to report a great deal of progress.

[4]
We had a last minute addition to the agenda, with Steve Majdali talking about black powder rockets and some very nice black powder rocket making tools he acquired while on travel. Black powder rockets are a classic form of amateur rocketry and involve many techniques that are broadly useful in other areas such as composite grain motors.

Steve Majdali shows the RRS his metal spindle for a cored grain type of 3-inch black powder rocket

Steve gave us a lot of great information specific to black powder making, pressing and a wealth of other practical information. Based on this new avenue of research, I felt the RRS would benefit more if Steve discussed this topic in more length in a stand-alone article soon to be published here on the RRS.ORG website.

[5]
The RRS has been in contact with the Additive Rocket Corporation (ARC) of San Diego. They are a startup company in San Diego with the goal of making high performance rocket motors using their novel design methodologies and 3D metal printing equipment. Discussions are still underway and thus there wasn’t much to tell. ARC was an exhibitor at the 75th anniversary symposium this year in April.

Additive Rocket Corporation (ARC) of San Diego at the 75th anniversary RRS symposium

[6]
In my discussions with ARC, they were kind enough to offer to 3D print a simple small liquid rocket chamber I designed. Prices are not cheap, but this futuristic manufacturing technique offers a great deal of complexity that is not easily nor cheaply replicated by traditional means. I have been in discussions with ARC and hope to have more to present at the next RRS meeting.

125 lbf thrust chamber design, uncooled; prototype for the RRS standard liquid project

[7]
Alastair Martin could not join us at October’s meeting. I was going to have him discuss the current topics of interest at the recent 21st Annual Mars Society Convention held this summer. Alastair is very involved with the Mars Society and the RRS.

Alastair will be at the November RRS meeting so we’ll put this topic on the next agenda.

[8]
New RRS members, Wilbur Owens and Xavier Marshall, are active with the Experimental Aircraft Association, chapter #96, at the Compton Airport in the Los Angeles area. EAA-96 is a like-minded group of enthusiasts centered on experimental aircraft. The EAA-96 has hangar space and a range of machining tools offered to their members.

Experimental Aircraft Association, Spirit of 96

Xavier had mentioned at the last meeting that the EAA would love to host a visit by the RRS. Accepting the EAA’s invitation, the RRS has scheduled a visit to the EAA in Compton on November 3rd at 10:00AM. The EAA will give an hour tour of their facilities and projects. We hope to foster a strong relationship between the EAA and the RRS.

Talk with Xavier Marshall, Wilbur Owens, the RRS president, vice president or secretary for details.

Experimental Aircraft Association (EAA) hangar
1017 W. Alondra Blvd.
Compton, CA, 90220
(310) 612-2751

One of the key points of discussion at this visit will be to discuss how the RRS and EAA can help each other or participant in joint projects. The RRS is interested in using the EAA hangar facilities if they are available. Annual membership at the EAA is $40 to the EAA national society and $40 more to the local chapter at the Compton Airport. As I understand but must confirm, with EAA-96 chapter membership, RRS membership can have access to the machining tools for building rocketry parts for those of us without facilities in our own homes.

Xavier had also mentioned that hangar storage was often very cost-effective which could be a service that the RRS could use as we look to expand our shop capabilities to our membership.

EAA Chapter 96 hangar, Compton Airport

The EAA hangar is just straight east and not very far from our regular meeting location in Gardena at the Ken Nakaoka Community Center just north of Artesia Blvd. (CA-Hwy 91). The address is above.

[9]
Osvaldo’s recent successful design of an alpha parachute recovery system was not able to be covered. We may expand this topic into a fully illustrated RRS.ORG article if we can not get this topic on next month’s agenda. This has been a quiet success and definitely worthy of exhibition to our membership.

[10]
Jerry Fuller of Aerospace Corporation had indicated interest in building and testing a larger subscale prototype of his liquid-infused hybrid motor grain. Aerospace had earlier this year successfully demonstrated a smaller prototype in flight at the RRS MTA. In choosing the next larger design, he has selected a common model rocketry size (98 mm) just under 4-inches which will allow him to use commercially available rocket body parts. Jerry is active with our friends at Rocketry Organization of California (ROC).

At this time, he is still working on the design until resources can be allocated. The RRS has invited him to present his results and the new prototype he has in mind. The RRS is happy to support private groups with a testing area and a community of amateur enthusiasts happy to assist.

[11]
The RRS had discussed having a small group of our membership go out to the next ROC event which is held the 2nd Saturday of the month. Unfortunately, neither I nor Drew were able to go this month. With the Friday night rains falling on the city, it might not bode well for the event at the Lucerne Valley as they must operate on the dry lake bed.

We are looking to coming out to the November ROC event in the Lucerne Valley and hope we can bring other RRS memmbers with us. In particular, some of our members are interested in getting more practical experience through the NAR or Tripoli prefect at ROC. Moreover, some of the RRS membership is seeking experience and support as we acquire letters of recommendation for the California pyro-op licensing in rocketry.

[12]
Saturday seminars have not yet been scheduled, but the RRS is still committed to offering an extended time period for fuller discussions by invited speakers.

[+] RRS member, Jim French, is a speaker of which we would be very excited to have. Jim was a development engineer at the famed Santa Susanna Field Laboratory here in Los Angeles during the development of the reliable and powerful H-1 engine and the injector for the massive F-1 engine. Later, he worked at TRW on the reliable, hypergolic fueled, Apollo Descent engine at TRW at their San Juan Capistrano testing site (now defunct). His book, “Firing a Rocket Engine” is available on Amazon and it is a great read.

Amazon.com – James A. French, Firing a Rocket Engine

[+] Reaction Research Society founder, George James, is another speaker we have been wanting to have. His founding work with his other organization, the Rocket Research Institute (RRI) was a great topic he covered only briefly at the 75th anniversary symposium in April.

[+] Rocketdyne retiree and materials expert, John Halczuk, is another potential speaker on the subject of his extensive research of the V-2 rocket. He gave an excellent talk last year at California State University in Northridge, on history of the V-2’s development and deployment. The V-2 guided many design decisions still used in modern rocketry today in both the United States and particularly in the former Soviet Union.

We were not able to discuss this topic in detail, but more information will be forthcoming, hopefully in the form of an announcement of our first Saturday seminar at the Ken Nakaoka Community Center on a Saturday morning.

[13]
The next RRS symposium date in 2019 will be set soon. Based on the powerful success of the 2018 event, the RRS has decided to further the tradition one more year. We hope to have an even better mixture of universities, private companies and government agencies.

Date to be announced in November, the RRS will hold the 2019 symposium at the Ken Nakaoka Community Center in Gardena

There was no time to formally raise the subject, but it was decided by the council members present at the October meeting that the 2019 RRS symposium date will be formally set by an offline discussion and the date officially announced at the next RRS meeting on November 9, 2018.

[IN CLOSING]
The next meeting of the RRS will be November 9th at the Ken Nakaoka Community Center in Gardena.

We will most certainly discuss the results of the MTA launch event scheduled for Saturday, October 27, 2018. I will build the agenda starting at the end of the month. Please contact the RRS secretary for ideas and information on meeting topics.

secretary@rrs.org

As per our constitution, the RRS will hold its annual nominations of officers for the next calendar year 2019 at the November 9, 2018 meeting. Voting by the administrative membership will take place thereafter and managed by our election chairman. Results will be announced at the next meeting on December 14, 2018.

Thank you for reading.

—- —-

MTA launch event, 2018-08-18

The RRS had a small event at our private Mojave Test Area (MTA) on August 18, 2018, to allow Richard Garcia to test his liquid rocket motor. Richard built a pressure-fed, 1000-lbf kerosene-LOX motor including all of the static fire test stand equipment and control valves.

desert morning at the MTA

Richard Garcia reviews his list in the MTA blockhouse

Switch panel and electrical cabling

Richard had spent a good part of Friday and early Saturday getting his test stand mounted and ready. He had made arrangements to share the contents of a liquid oxygen dewar to supply the oxidizer he needed for his test with other RRS member, Sam Austin. Sam was also preparing to fire his liquid rocket motor at the Friends of Amateur Rocketry (FAR) site just south of the RRS MTA on this same day. Arriving early in the morning, I was glad to help Richard with the final preparations at the RRS MTA to start the initial checkouts and ultimately a successful hot-fire test.

Richard checks the wiring and pneumatic line connections

Richard’s 1000 lbf kerosene/LOX motor was designed for a chamber pressure of 300 psig and used a pintle-type of injector with an ablative lined chamber and graphite nozzle.

Richard Garcia tests both flow paths of his pintle injector in water flow

Ablative liner, G10, sits inside the combustion chamber of Richard Garcia’s 1000 lbf kerosene-LOX liquid rocket motor

Graphite nozzle within the chamber assembly of 1000 lbf kerosene-LOX motor

He brought his motor hardware to the January 2018 meeting, but now it was finally time to prove his design with a hot-fire test.

Richard shows his liquid rocket motor at the January 2018 meeting

Richard’s test used a high pressure nitrogen bottle to pressurize his propellant tanks, the left one for liquid oxygen (LOX) and the right one for kerosene. This regulated inert gas source also provided pneumatic pressure for the propellant valve actuators.

Richard’s static fire tanks and equipment mounted and ready for test, 2018-08-18

The top half of the thrust stand with the tanks and valves is fixed to the structure. The engine is suspended below and is secured to a plate which was mounted to an S-type load cell. These devices are an affordable means of measuring both compressive and tensile forces by the internal strain gauges built into them.

An S-type load cell used for thrust measurements in the static fire equipment

Caution was taken to keep the motor clean during handling and installation by caps on the ports and closing off the nozzle with aluminum foil.

View of Richard’s 1000-lbf motor from below; aluminum foil covering the nozzle exit to prevent foreign object debris (FOD) in the injector

With the validation testing complete and all valves are working, fuel was loaded, then preparations to load the cryogenic liquid oxygen (photo courtesy of Rick Maschek of FAR)

Careful review of the firing procedure before getting down to testing

Preparing for LOX transfer (photo courtesy of Rick Maschek of FAR)

All propellants loaded, everyone in the blockhouse, running the final checks before starting the countdown (photo courtesy of Rick Maschek of FAR)

The view from the blockhouse, a nice clean start of the liquid motor (photo courtesy of Rick Maschek of FAR)

Another view of the rocket firing from Richard’s tripod-mounted camera, 2018-08-18

A few seconds later with the dust kicking up from the motor firing, 2018-08-18

Closeup view of the rocket firing from a small mounted camera; it blew over from the firing but capture this image

Most of the testing seemed to work well. The motor had a clean start and stable run time for the full 5 seconds duration that Richard had predicted. Post-test inspection showed the engine to be in very good condition.

A view from up the nozzle after hot-fire; all looks good

Surface of the 1-inch thick steel plate was melted from the impinging plume; perhaps we’ll mount the next engine a bit higher

Tank pressure measurements were able to be recorded, however the thrust and chamber pressure (Pc) measurements were corrupted. Richard is working on downloading the hot-fire video to be posted on the RRS YouTube channel.

Soon he’ll disassemble the injector and chamber to see if the motor can be fired again. This was a great success for the RRS and we hope this to be the start of several liquid motor hot-fire tests as the RRS continues to improve on this powerful type of rocket.

Richard Garcia stands next to his 1000-lbf kerosene-LOX liquid rocket motor at the RRS MTA, 2018-08-18

I hope that Richard will be able to present his results at the next RRS monthly meeting on the 2nd Friday of the month. The next RRS meeting will be Friday, September 14, 2018 at the Ken Nakaoka Community Center in Gardena, California.

The RRS would also like to thank Mark Holthaus and Rick Maschek of FAR for their assistance on this test.

***