Category Archives: Uncategorized

October 2020 virtual meeting

Posted on by

by the Reaction Research Society

The RRS held it’s monthly meeting by teleconference on October 9th at our usual starting time of 7:30pm. We had a few members calling in from out-of-state. We had a few new topics to cover.

Some of the attendees to the October 2020 monthly meeting

SUMMARY OF RECENT MTA EVENT

We held a work event at the Mojave Test Area on October 3rd which was very successful despite higher temperatures for that autumn Saturday. We cleared a lot of tumbleweeds, mended the barbed wire fence at our front gate, painted the metal window gratings on the front of the Dosa Building and even cleared off the decks of the large vertical test stand. We had a lot of great help and we hope to continue making these site improvements to make our facility more attractive and useful.

The large vertical test stand at the RRS MTA after some clearing.

We agreed to meet at the MTA again on November 7th which will coincide with a static fire test of USC’s Rocket Propulsion Lab latest multi-grain solid motor design. We will also attempt to remove and replace a bent panel on the vertical thrust stand. The nitrous oxide hybrid rocket by Dave Nordling, Larry Hoffing and Osvaldo Tarditti is also ready for launching. If there are other member projects that are ready we will add those to the event and notify the pyro-op in charge.

LIQUID ROCKET PROJECTS

Liquid rocket projects have become more popular recently and some have started within the RRS.

Loyola-Marymount University (LMU) in Marina del Rey started a capstone project for their upper classmen in their undergraduate aerospace engineering program to design and build a large liquid rocket. The LMU Lion project was inspired by the FAR-MARS competition. Dave Nordling has been supporting the early design work on behalf of the RRS starting early this calendar year prior to the pandemic restrictions ending in-person meetings. LMU has restarted the project with the new academic year with a series of specialized coursework and short presentations on topics from experts around the industry. Dave was glad to present the history and capabilities of the RRS. The presentation was well received and LMU has looked at using our vertical test stand when they get their first liquid rockets systems ready for test.

Loyola Marymount Aerospace Research Society

The Compton Comet project at Tomorrow’s Aeronautical Museum has been restarted with RRS members, Waldo Stakes, Kent Schwitkis and Dave Nordling. The Compton Comet is a liquid rocket to be built, tested and flown at the RRS. It is a larger vehicle design which has several parts built and will use a surplus XLR11 single-chamber fueled by LOX and a 75% ethanol-water blend, It is a very ambitious project for the Compton College STEM students but it will provide an excellent means of learning practical skills.

Engine section built from a surplus tailcone and ethanol-LOX engine sits on the workbench

UCLA is continuing Project Ares for this next academic year. Last year’s liquid rocket vehicle design was in its final preparations for a Spring 2020 launch at FAR until the pandemic closed campuses around the country including the UCLA Lab. UCLA invited a few RRS members to attend their preliminary design review by teleconference. They are proceeding with several design improvements from last year’s vehicle design and when their laboratory access is restored under carefully regulated conditions, they hope to have another static fire at the RRS and flight from FAR next spring.

Thr Rocket Project at UCLA

Richard Garcia had started a design for a small liquid fueled rocket that would be easier to build and serve as the basis for a common or standard design for society members wanting to test and fly a liquid rocket at reasonable cost. Propellants are ethanol and liquid oxygen. The design has features proven from past successful liquid motor testing at the RRS MTA. The first prototype of the small 125 lbf motor is in build now. After successful demonstrations of the motor in hot-fire, the vehicle will be built.

Illustration of the RRS standard liquid rocket concept

There is a rocket hangar space opening up at the Compton/Woodley Airport which RRS members will soon have access. It has been a goal to have a work space within the city centrally located for most of our members. Operations at the rocket hangar will be limited to construction activities and small-scale pressure tests and cold flow operations, but it will offer our members a greater convenience for those with limited working space in their homes. Contact Wilbur Owens and Xavier Marshall for details. Social distancing and mask protocols would apply.

MTA FIREFIGHTING MEASURES

Fires are one of the greatest risks that come with amateur rocketry. At the behest of several members we have been discussing way of better preparing to fight fires from our site. The roughly one dozen pressurized water containers we have in our storage container are filled and made ready at every event. These have been useful for containing any fires starting at the pads. The RRS is looking at storing large quantities of water at the MTA. We’re also looking at trailer mounted water tanks that could be pulled by a small all-terrain vehicle (ATV) with a motorized pump spray system. These are commonly found in agricultural locations and would be an excellent addition to help limit the propagation of downrange fires until county resources can arrive.

An example of a 200-300 gallon water tank with a motorized pump system

MTA FACILITY UPGRADES

New restroom facility designs have been discussed over this summer. Concepts have been discussed with contractors and firm cost proposals are being prepared. Issues like cost and permits are important concerns. The society last year approved this facility upgrade project as the top priority.

One of several concepts for a new restroom facility at the RRS MTA under discussion

ANNUAL ELECTIONS FOR EXECUTIVE COUNCIL

Next meeting teleconference will be held on November 13th. After appointing an election chairman, we will be holding nominations for executive council positions at the meeting. Administrative members of society are encouraged to participate as we select our next year’s leadership. Active membership is also required so be certain to pay your dues if you haven’t all year.

If there are any questions or comments, please contact me RRS secretary. You can also follow the RRS on Facebook and on Instagram.

In Memoriam: Brandy (Robert “Bob”) Bruce-Sharp (1953-2019)

Posted on by

by Larry Hoffing, Events Coordinator, Reaction Research Society and Korey Kline (contributing)

In January 2019, Brandy (Robert “Bob”) Bruce-Sharp passed away. As reported by Mark Clark and Tripoli, Brandy went quickly from non-Hodgkin’s lymphoma. At the BALLS 28 launch this past September, Brandy and wife Abbie’s ashes were launched and spread in an Aerotech M1939 rocket.

from left to right; Robin Meredith, Jim Bornwell, Jane (Brandy’s sister), Mark Clark, Gary Rosenfield

Bob was my friend and fellow student at Los Angeles (Robert H. Goddard) Pierce College rocket club that I founded in the early 1970’s. Around this time we met a high school kid named Korey Kline, he was only fifteen at the time but already a veteran shop mechanic. His high school rocket club, inspired by the Pierce club, found a Korean War five-inch diameter HVAR rocket at a vacant military recruiting office.

Bob Bruce, Michael Gill and Larry Hoffing of the Robert H. Goddard Rocket Society of Pierce College in Los Angeles
Bob Bruce and Larry Hoffing stand at the launch rail for a row of model rockets in the 1970’s

We proceeded to convert it to a zinc-sulfur rocket which required bolting some ports of the multiport nozzle shut, adding fins, and a payload section- I think Bob’s mother sewed the parachute. I did most of the machining in the school’s metal shop while some of the welding students added the fins. I remember hauling the thing, which weighed about 40 lbs unloaded, for a show-and-tell presentation at the Pacific Rocket Society (PRS) which met at the (now defunct) Northrop Institute of Technology in El Segundo.  B. J. Humphreys was the PRS president at that time.

B.J. Humphreys, past president of the Pacific Rocket Society and builder/pilot of the first rocket-powered wheelchair
Bob Bruce and Larry Hoffing in September 1972

Bob named the rocket “Bifrost” (pronounced “BIF-roast”) which is the old Norse term for the rainbow bridge to Asgard.  Our mission was to fly Bifrost at the Mojave Test Area (MTA) near the town of Cantil, CA, where the RRS, FAR and Polaris Inc. (under the direction of Dave Crisalli) currently test. In those days the bunker was covered with telephone poles that had been trucked out by RRS member John Mariano and his cousin in the 1960’s.  There’s a pile of them still laying at the MTA to this day! Access to the site was by dune buggy. The yellow blockhouse with its ballistic glass windows still stands at the RRS MTA.

This sets the scene for the launch of the missile on a wooden home-built Bruce rack – 3 aluminum fins had been welded onto a cowling over the casing as we hadn’t realized the launch racks were built for four-fin rockets (Hint: let your new members know about the launch rack configuration ahead of time). The PRS had most of the pyro-op’s at that time.  The PRS pyro-op in charge was afraid we’d blow up the rocket and surrounding area so he made us fill the casing half way with sand. It must have weighed 80 lbs.

5, 4, 3, 2, 1, ignition! The rocket lifted off, flew a short distance, and crashed. The failure to go the distance was attributed to the multi nozzle ports, we didn’t bolt enough of them shut to build pressure. There is a photo of it flying, I gave it to my machine shop professor, and unfortunately don’t have a copy.

Bob was a consummate modeler and draftsman. He won top prize from Estes in 1972 for his remote control Space Shuttle which was a thing of beauty.

Bob Bruce wins first prize in the Estes rocket modelling competition for his space shuttle design

Bob started a rocket kit company with Korey in the mid 1970’s called California Model Rockets, a precursor to large/high power rocketry. One of my biggest regrets in life is not joining them in this endeavor. Bob and I had previously invented the largest model rocket in the world we called “The Wopper” . The California State Fire Marshal rules at the time was that model rockets had a weight limit of 1 lbm including the motor, so designing it was no easy task. We got the brilliant idea one day of enclosing foam rings and horizontal balsa slats with construction paper to create giant tubes. The biggest F-sized motor at the time was F-100’s made by Flight Systems Inc. The large model rocket flew spectacularly to about 300 feet.

Bob relocated to Arizona sometime in the 1980’s to pursue drafting, and afterward I lost touch with him. However, my memories are vivid of us mixing and testing “Blue Knight” candy fuel (sugar motors), and launching model rockets at Half (Hof) Mile Square in Fountain Valley, CA (a former air ship site) with the Westchester YMCA Rocket Club. Hof Mile was a trip. Wheeled sail cars raced around on the landing strip as we launched rockets. We’d even have to pick up the gate keys from the local base commander. It was here while looking for a rocket in the tumbleweed that I stumbled upon a huge, beautiful red fox when the area was still wild back then.

Korey remembers Bob as his earliest mentor for rocketry. “By example he taught me to think outside the box!” Korey says he was only fifteen when he met us and we (and his mother) had to drive him to the rocket club meetings. Bob also introduced Korey to B. J. Humphreys of the PRS and Gary Rosenfield at the RRS.

One project we all worked on together was building the Hang Loose Bi-Plane, a one-man glider made of bamboo, wood, wire, & plastic sheeting. We cut and bent bamboo spars for the airfoil wings at Korey’s house over his mom’s gas stove. The glider had around a 14-foot wingspan and a 12-foot rudder.  It was Korey that drew the short straw to fly first. With Korey hanging in the center and the two of us at the wing tips we took off running from the top of a hill in Granada Hills. Korey lifted off about 10 feet in the air and started sailing down towards a school fence at the bottom where he bailed out before hitting.

Another thing we did that I can mention now was flying model rockets out of Korey’s in ground swimming pool. We sealed the motor and electric igniter with wax and lowered the rocket and launch pad to the bottom of the pool with the controller on deck. All I can say is that a sea launched rocket is pretty cool when it breaks the surface!

There were many interesting things we did with Bob and we remember him dearly. He loved his muscle car too, I remember other drivers on the 405 Freeway coming along side trying to race us, but Bob wasn’t a speeder, just a tinkerer. I often wonder what became of that car.

Mark Clark further reports on the Tripoli members forum:

“Brandy [aka Bob] started flying rockets in the 1960’s and at Miles Square Park and very early Lucerne launches. Getting into high power in the late 1980’s, he had moved to the Phoenix area and was a founding member of Arizona High Power Rocketry Association (AHPRA).

Brandy started Sonic Systems that locally sold reloads and nationally 7 1/2″ sized mosquito-type nosecones. Those who saw the ads in High Powered Rocketry (HPR) magazine will remember them. Brandy was also involved with the BALLS launch for the 18 years AHPRA was involved and a frequent poster to these forums. Brandy was a great friend for nearly 30 years.”

www.ahpra.com

www.ballslaunch.com

Brandy “Bob” Bruce-Sharp at the BALLS 25 launch with his up-scaled Centuri Enerjet 2650 rocket

A Tribute to Mr. George Dosa

Posted on by

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.