MTA launch event, 2021-05-01

by Dave Nordling, Reaction Research Society

The Reaction Research Society held an event at the Mojave Test Area (MTA) on May 1, 2021. Dave Crisalli was the pyrotechnic operator in charge. RRS president, Osvaldo Tarditti, was also present along with myself, It was not to be a launch event as all planned tests were static firings by the UCLA liquid rocket team and the UCLA hybrid motor team. The winds were very high that day consistently above 20 MPH and gusts above 50 MPH at times. The weather otherwise was very cooperative with comfortable temperatures.

Other than gusting and persistently hugh winds, it was a great day at the MTA on 5/1/2021

Dave Crisalli gave a safety briefing in the George Dosa building to all attendees before the first static fire campaign would begin. The RRS pyrotechnic operator in charge is responsible for the safety of all during the event. Hazard identification (spiders, snakes, sharp objects) and good practices (hydration, sunscreen) are always part of the briefing, One of the most important things, Dave Crisalli mentioned was not to be in a hurry. It is very important to take the proper time to do things correctly and safely even if it means not proceeding with the intended test that day. Taking your time means avoiding mistakes and improving your chances for success.

Xavier Marshall observes the UCLA hybrid motor controls setup at the RRS MTA on 5/1/2021.

RRS members, Bill Inman and John Wells came to the MTA for the event, but only as spectators. The Solar Cat project is still active and undergoing improvements to its sun tracking method. Bill is also expanding the collector area and adjusting the necessary support structures. It is likely Bill and John will be back for the next RRS MTA event.

Dave Crisalli (left) and Bill Inman (right) at the RRS MTA vertical test stand on 5/1/2021

Also in attendance was the Compton Comet team who have all recently joined the society as members. It was their first time visiting the MTA and getting a chance to see another university team conduct liquid rocket test operations at our vertical test stand.

Members of the Compton Comet team, Manuel Marquez, Aarington Mitchell, Tre Willingham (from left to right) wait at the Observation Bunker at the MTA for the hybrid motor firing with Waldo Stakes (at right).

RRS member, Wolfram Blume came by the RRS MTA to take measurements of the vertical test stand for a future static fire test of his ramjet upper stage engine. He intends to use a leaf-blower compressor motor to simulate foward air flow, but a lot of calculations and planning is required before proceeding. The vertical test stand has a winch and pulley system still attached from Richard Garcia’s liquid motor test in 2017. It should be adequate for Wolfram’s lifting needs when mounting the test equipment to the stand.

The vertical test stand with the winch and pulley system still mounted.

The UCLA team spent the night before on our site setting up their equipment. This advanced planning paid off as they were ready for the first of two hot-fires of the liquid rocket just past noon.

Camera adjustments made before the first hot fire of the UCLA liquid rocket on 5/1/2021

Often, it can take several hours to verify all systems are in good working order before testing especially with a liquid rocket, The hybrid rocket was no exception that day.

The UCLA hybrid motor team installs the fuel grain and nozzle into the 98mm standard motor casing,
The UCLA hybrid motor mounted for static fire on the RRS MTA I-beam

One of the two load cells had failed so the two teams had to share the same load cell between the hybrid motor and liquid motor firings. UCLA chose to let the hybrid team go next after successful results were seen with the first firing, The UCLA hybrid motor team corrected a few issues and were able conduct a successful hot-fire by late afternoon.

The society members in attendance also had time to make some minor repairs to the new mobile trailer asset, A steel plate was added to keep intruders from entering. Thanks to Waldo Stakes for doing the welding for this temporary fix.

The mobile trailer at the RRS MTA needs a lot of repairs

There was sufficient daylight remaining for a second hot-fire of the UCLA liquid rocket, The team had another engine with the previous injector design from last built and ready with a fresh internal ablative liner. They had retanked another load of ethanol and the liquid oxygen cylinder had sufficient stores for another loading cycle.

Preparing for liquid oxygen transfer to the propellant tank

Thanks to the hard-won, acquired experience of the UCLA team and their commitment to training new members and holding to their proven procedures, they were able to conduct the second firing safely for an impressive finish that day.

The UCLA liquid rocket team poses before their liquid rocket after a second successful hot fire on the same day.

Initial data from both UCLA static firings of their liquid motor suggest that the 650 lbf nominal thrust motor outperformed expectations and will be ready for vehicle integration and flight by May 29, 2021. The UCLA team had reason to celebrate at the end of the day. The RRS was glad to be a part of UCLA’s continued campaign to fly liquid rockets that are competitive with any university team in the country.

For other universities interested in working with the RRS, please contact the society president submitting a Standard Record Form downloaded from our website,

MTA launch, 2020-02-22

by Dave Nordling, RRS.ORG

The Reaction Research Society (RRS) held a launch and static fire event for three UCLA teams and one of our own RRS teams at the Mojave Test Area (MTA) on Saturday, 2/22/2020. Poor weather was a persistent threat from the day before with light rains coming and going from the early morning hours and even throughout the launch day. Winds calmed just enough for a successful rail launch of UCLA’s solid rocket motor. Fortune favors the bold and this proverb did not disappoint our participants that day at the MTA.

Rain clouds still filled the skies on a very calm morning. Preparations began for UCLA’s solid rocket motor launch from our rail.

With the liquid and hybrid rockets, Osvaldo Tarditti, our RRS president was our pyro-op in charge. I served as his apprentice for this event as part of building my experience for becoming a pyrotechnic operator 1st Class. This was the second of two apprenticeships I have served under two first class pyrotechnic operators. Osvaldo gave our safety briefing to all of our attendees that day before beginning the scheduled events.

UCLA gathers around to hear our safety briefing. Most have been to the RRS MTA before but we give the briefing each time to reinforce good practices.

UCLA had three projects ready for flight or static-fire at the MTA. The first was the solid motor driven rocket built by the UCLA Project Prometheus team. They were using a commercial K-sized motor with a vehicle equipped with a downward-facing camera built into the lower body.

UCLA’s Project Prometheus built a rail-launched rocket with a commercial solid motor.
The Gerald Ticonderocket in the color scheme of a common wooden pencil.

Elizabeth, the UCLA team leader for this solid rocket project assisted me with the launch preparations. The rail launched rocket worked perfectly and the recovery system operation was visually confirmed as it descended to the west of our launch site.

My 2-1/2 inch rocket with a commercial H-222 hybrid motor from Contrails Rocketry. The body has been extended for better packaging.
The motor has been successfully loaded into the body tube complete with retainer. All that remains is to complete the recovery system packaging and find our next opportunity to launch.

Larry, Osvaldo and I have made progress on improving the 2-1/2 inch rocket with a commercial H-sized hybrid motor. Larry made an extension on the payload tube to fit all of the recovery system more easily. We have the Contrails H222 motor fully integrated and ready for loading.

The RRS reloaded and refurbished our nitrous bottle and valve manifold, but we didn’t get to loading operations.

Our nitrous bottle was refurbished and reloaded for the testing and we successfully conducted a valve test of the manifold that verified that our control box works well. We were reworking the black powder charge and repacking the parachute when the weather shifted and the winds picked up.

Weather changes quickly in the desert. Our smaller rocket missed our window for launch that day.

The weather was perfect 15 minutes earlier with the launch of UCLA’s solid motor, but at the time we were discussing launch of our hybrid motor it became clear the weather would be getting worse and winds too strong for launch of a smaller rocket such as ours. Since the RRS will be returning to the MTA site on Sunday, March 1. We figured we would do some minor improvements to the payload packaging and try again when we are fully confident and hopefully with better weather for the flight.

The hybrid motor is secured to the RRS I-beam. This is one of the very first assets of the society which predates our arrival to this MTA site.
UCLA hybrid rocket team making load cell adjustments on their thrust stand before hot-fire.

UCLA’s hybrid rocket team under the same name, Project Prometheus, sought to static fire a commercial M-sized hybrid motor as part of getting ready for a flight later this semester. They secured their test stand vertically to our historical I-beam location which was the original article from even before the RRS moved to the current MTA site in 1955. The RRS was glad to assist UCLA in securing to this location and making ready for nitrous oxide fill operations then ignition for static fire measurements.

Hot-fire of the hybrid motor took place around 5pm which by all appearances was a success. The motor case was intact and post-flight assessments looked promising, but an error in data acquisition resulted in no thrust measurements being recorded despite successes in pre-test checkout. UCLA is considering re-attempting this testing at the RRS MTA very soon.

UCLA working on their liquid rocket’s pressurant system.

The last of the three projects would be the static fire of the liquid rocket for Project Ares. The liquid rocket team mounted their hardware to the vertical test stand simultaneously as the hybrid rocket team mounted to the I-beam thrust stand. Both teams worked hard to be ready before the other but in the end, the liquid rocket took longer to be ready.

This would be a second attempt to static fire their liquid rocket system from 2/1/2020 at the RRS MTA. UCLA had been finding and fixing leaks in their pressurization system in the weeks leading before this test.

Making some preliminary checks before commencing liquid oxygen tanking of the rocket.

They proved their fixes before departing to the RRS MTA, but again ran into problems with leakage in the pressurant system. After several more repairs and discussion with the team and pyro-op in charge, the decision was made to proceed. All other systems had passed checks and the leak rates measured were consistent and would only reduce the burn time while assuring safe engine hot-fire.

UCLA begins the final operations following their proven checklist.

Around 5:30pm in the last light of that long day, UCLA’s liquid rocket was proven in a brilliant, steady and powerful hot-fire of their ethanol-LOX propellant liquid rocket. It was an exciting time which showed reasonable thrust results that led UCLA to conclude that the testing that day was sufficient to proceed with flight vehicle integration operations for their motor.

UCLA’s static fire on 02/22/2020 was steady and well controlled.
All initial inspections of the liquid motor looked good. Preliminary review of the data was encouraging and will be useful in grounding their vehicle performance predictions.
In the last rays of daylight, all three UCLA teams pose with their project’s pride at the RRS MTA vertical test stand.

UCLA did a great job of cleaning up at the site. They also returned the LOX dewar back to the nearby Friends of Amateur Rocketry site. We’re thankful to everyone who made this day a triple success. Our next launch event is scheduled for March 1st. We’ll also discuss this and our other recent MTA events at the next RRS meeting on March 13, 2020.

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.


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.