August 2019 meeting

by Dave Nordling, Secretary, RRS


The Reaction Research Society (RRS) held its monthly meeting on Friday, August 9, 2019, at the Ken Nakaoka Community Center in Gardena. We were glad to welcome a new member to the society, Drew Sherman. Frank mentioned that the latest educational event with LAPD CSP was going well and that we can expect the next launch event to take place on Saturday, September 21st.

Drew and Arthur Cortopassi attend the August 2019 meeting of the RRS

We began our meeting with the call to order and reading of the treasury report. This August meeting would try to catch up on topics intended for past meetings.

[1] MTA launch events since the last meeting

The first topic on the agenda was discussion of the recent launch events held at the MTA since our last meeting. The RRS hosted Operation Progress at the MTA on July 13th. The launch report for this last event with the LAPD CSP program has already been posted.

UCLA held its second of two high school rocket launch events at the RRS MTA on July 31st. This was supported by Osvaldo Tarditti and Larry Hoffing as the six teams flew and recovered egg payloads using model rockets with “G” sized commercial motors. The event was a great benefit to the young participants and a welcome change of pace as the RRS welcomes model rocketry and amateur rocketry alike.

UCLA supports high school rocketry, the RRS was glad to host two events at the MTA in July 2019.

RRS members, Jack Oswald and Cooper Eastwood, had a launch event at the RRS MTA on August 3rd, delayed 2 weeks from the original July 20th date. The “50 for 50” rocket was built to reach 50,000 feet on the 50th anniversary of the Apollo 11 moon landing. Jack’s large solid motor was impressive as he and his family worked hard at the event to get his rocket ready for flight.

Jack’s mom carefully folds and stows the streamer payload which would be the first deployment after the booster reaches apogee somewhere near 50,000 feet. The Oswald family was a big part of making this flight possible and the vehicle integration went quite smoothly even in the August summer heat of the Mojave Desert.

A last minute inclusion was a radio tracking package made by Friends of Amateur Rocketry (FAR) member, Joe Conway. Joe was kind enough to allow his tracker to fly in Jack’s rocket as his device was not operational. Our fellow amateur rocketry enthusiasts at FAR came over to assist in the launch and the RRS was glad to have their participation.

Jack’s rocket weighed in at over 82 lbs with 30 lbs of AP composite propellant in four Bates grains within his booster. With a team of four to six people, the booster and instrumented payload section were assembled and loaded into the rails.

Cooper Eastwood, Jack Oswald and Prof. Barsoum Kasparian (holding the booster igniter) inside the George Dosa building at the RRS MTA

Unfortunately, the “50 for 50” rocket flight was a failure and the booster exploded shortly after ignition. Based on the film footage, ignition of the motor was achieved and the rocket lifted about two to three feet within the rail before an over-pressure event ruptured the booster and destroyed a great deal of the launch rails. No one was injured in the firing, but there was a large amount of clean-up to be done. We were very thankful to all of our attendees for their attention to safety and assistance in carefully gathering for disposal of the unburned propellant scattered from the violent end of this rocket.

The 50 for 50 rocket just after ignition and lift-off. This is the last frame before the booster disappears into a cloud of debris and smoke shattering the launch rails into a twisted mess.

Given the extensive damage to the rails, refurbishment will be costly. The RRS is already assessing plans to replace the necessary parts to restore this large adjustable rail launcher very soon.

Initial frame taken from the observation bunker as the “50 for 50” booster shatters in the rails throwing the payload upward with the streamer and parachute coming out

Jack is preparing a report of his entire build processes and some theories regarding what happened and what could be done better. This report will be submitted to our membership, but Jack will be unable to present his findings in person as he will be leaving for his freshman year at MIT. Even in failure, it’s important to keep good records. The RRS is a scientific society which insists on good record-keeping and sharing knowledge to make each project better than the last.

It was an amazing effort by a group so young. They had great support from many people and sponsoring organizations who donated money and resources to completing their rocket for this test. The RRS was proud to help our members achieve a great learning experience and in time, try again.

John Newman of FAR standing next to the damaged rail launcher examines an unburned grain fragment from the “50 for 50” booster.

Going back to the MTA launch event of July 13, Brian Johnson was able to present a summary of Kent Schwitkis’ trajectory analysis of the Compton Comet alpha rocket flown that day at the MTA event for Operation Progress and LAPD CSP. Kent did a thorough analysis of the optically measured positions of the alpha as it left the rails within the view of the footage taken. Using the video footage taken of their alpha fired from the RRS MTA box rail, careful scale measurement of key landmarks in the background, the software program can make reasonable estimates of the position, velocity and acceleration of the rocket as it is seen and timed frame by frame in the video.

Brian Johnson goes over the trajectory analysis based on video footage of the July 13 flight of the Compton alpha rocket. Kent Schwitkis performed this analysis using a physics software package which provided reasonably good results given the number of potential difficulties in using an optical measurement approach.
The trajectory data plotted in Excel showed a clean acceleration pattern which matched expectations from past testing of the alpha.

The optical measurement approach provided some direct confirmation about the starting acceleration (95 G’s) and burnout speed (200 m/sec) of the RRS standard alpha flown that day. Kent Schwitkis’ method has great potential. The best course of action would be to conduct further tests of this kind to get a larger data set to confirm the statistical accuracy and variation between similar alpha rockets flown. The society will have this opportunity at the next event planned for September 21st.

[2] RRS standard liquid and the TAM project

Richard Garcia, our director of research, has created a prototype design for a simple liquid rocket that after some initial trial and error could become a standard project at the RRS much like the alpha and beta have become for micrograin solid propellant. Richard has created a materials list and the society is in the process of acquiring the necessary items and will begin construction of the initial prototype. For now, it is too early to say what this standard design will look like, but as many past members have built their own liquid rockets over the years, the RRS can draw upon a sizable base of past knowledge to create a modest liquid rocket that is both powerful and practical for future members to try.

I have been working with a small group at the Tomorrow’s Aeronautical Museum (TAM) at the Compton Airport. This project has a simple goal of creating a ground testing system to hot-fire a surplus LR-101 vernier motor. TAM has acquired a few of these kerosene and liquid oxygen LR-101 motors which have internal cooling passages and are made for long duration firings. Although the engine is already made, building the necessary regulated pressurization system and valves will be the primary challenge. This work can easily benefit other liquid rocket projects.

[3] RRS social media improvements

This is a regular agenda topic to be discussed at each meeting with the goal of finding ways to improve our presence in social media platforms and on the internet in general. Bill and Alastair, our two media coordinators, were both absent at this meeting so this topic will return next month as planned.

We’ve had a few new posts on our Instagram feed with recent events. Bill Behenna recommended that on flyers for future RRS events, the addition of a QR code to link back to our official webpage or other important information is something we should do.

[4] Pyrotechnic operating licensing at the RRS

The RRS has been working with CALFIRE on having more of our membership becoming licensed pyrotechnic operators to better enhance our operations and foster amateur rocketry in general. Osvaldo Tarditti, Larry Hoffing and myself have all been working through the licensing process. We encourage more of our membership to spend the time to prepare their applications and gather letters of recommendation necessary to begin the process. This will be a slow process, but as more pyro-op’s at the RRS become available, more able our society will be to hold events and support other rocketry groups in their projects.

[5] New RRS alpha payloads

The RRS holds many launch events throughout the year with Los Angeles area schools thanks to our partnership with the LAPD CSP. These events have from six to twelve alpha rockets flown from the RRS MTA at the conclusion of each program but they have empty payload tubes. This represents a great opportunity to fly more payloads.

John Krell has been working on an instrumentation package that can record high accelerations, barometric pressure and capture high speed data all in a compact package that fits in the tiny confines of an RRS standard alpha rocket. There are many commercially available instrumentation packages for model rockets which have larger plastic bodies Given the smaller internal diameter of an RRS standard alpha rocket, many of these great devices simply do not fit. John’s design seeks to make use of the latest instrumentation chips all in a long thin compact package ready for use in the RRS alpha. With luck, his device should be ready for flight at the next RRS MTA launch on September 21, 2019.

John Krell shows his latest breadboard model of his alpha instrumentation package.

SImilarly, Brian Johnson, in partnership with Kent Schwitkis and Compton College, has been working on an instrumentation payload of their own design for the RRS standard alpha. The first flight of his payload on July 13, 2019, was not successful as it failed to start recording. Brian has worked to improve the design, but the fundamental principles were sound. A second flight of this design at our next launch event at the MTA on September 21, 2019, should prove to be successful.

Brian Johnson’s alpha payload designed to fit inside the aluminum nosecone of an RRS standard alpha.

[6] Discussion of the next RRS symposium

The RRS opened discussion about the possibility of holding another symposium in the next calendar year, 2020. Previously, the society had decided not to hold another symposium after 2019 until two years later for both reasons of cost and resources necessary to conduct the event. While the society has not formally decided whether or not to have a 2020 RRS Symposium, the executive council did decide to study the matter further based on continued success and enthusiasm by past attending organizations.

The RRS will make a decision on this matter before the next meeting. If the RRS does decide to proceed, we must begin preparations in the latter part of the year to allow sufficient time to contact participants giving them time to prepare for a symposium in the spring as was done since our 2017 RRS symposium. Further, full engagement of our membership will be critical to keep this string of successes going strong.

IN CLOSING

As the meeting adjourned, RRS member, Mohammed Daya showed us the two model rocket bodies he purchased at a Northrop-Grumman swap meet recently. These were built by a retired rocketeer who wanted his hobby to go to another enthusiast.

Mohammed Daya shows Osvaldo Tarditti and Wilbur Owens the two model rocket bodies he bought at a swap meet. F and G type commercial motors look to be the right size.

As these two rockets only need some minor repairs and suitably sized commercial motors to be installed, we hope Mohammed will be able to launch them from the MTA on September 21.


The RRS will hold our next meeting on September 13, 2019. We plan on discussing three very important subjects:

(1) RRS MTA facility improvement plans including a new restroom facility, a new blockhouse and replacement of the large box rails damaged in the August 3, 2019, launch attempt.

(2) Discuss the initial draft of the updated Constitution as presented to our attending membership by the 2020 RRS Constitutional Committee.

(3) RRS decision on the next symposium.


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

secretary@rrs.org

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