May 2021 Virtual Meeting

by Keith Yoerg (RRS Secretary)


The latest meeting of the Reaction Research Society took place this past Friday, May 14th and had 20 attendees – including a guest presenter and a project update from the Compton Comet team, which is composed of RRS members. We kicked off the meeting saying vitrual hello’s and catching up on personal updates.

Screenshot of discussion during the monthly meeting

UPCOMING EVENTS AT THE MTA

The group kicked off society business by planning for upcoming MTA events later this month. Wolfram Blume is continuing progress on the Gas Guzzler, but windy forecasts continue to limit his ability to do further launch testing. Osvaldo and Wolfram planned to visit the MTA on May 16th to do a practice setup for a future static firing and some housekeeping tasks at the property.

Osvaldo also informed the membership about an active day planned for Saturday, May 29th with groups from UCLA planning to do another static firing of their hybrid motor and a liquid rocket launch to 33,000 ft. and a team of students firing model rockets. Several additional RRS members expressed interest in attending this event.

GUEST PRESENTATION – COBRA FIRING SYSTEMS

Scott Smith, the founder of Cobra Firing Systems was our guest presenter for this month, continuing our recent discussions on wireless launch controllers. Scott has been in the pyrotechnics industry for 10 years, and developed Cobra into a 25-person company with roughly 14,000 customers around the word. They have worked with Mythbusters, Disney, and the US Military to name a few.

Scott describing the underlying technologies behind the Cobra Wireless Firing Systems

RRS member questions for Scott focused on safety, in particular the risk of misfires and adding a physical shunt to the system. The data is encrypted, includes checksums, and is built around a US-based company Synapse, which has allowed the company to avoid any reports of accidental misfiring due to stray wireless signals. Cobra firing boxes are modular in nature and allow for what the company calls a “slat” – which allows for a cap to be used as a physical, mechanical shunt on the system.

MEMBER PRESENTATION – COMPTON COMET

RRS student members Manuel Marques, Aarington Mitchell, and Tre Willingham presented on the status of their project the “Compton Comet” which is being built at the Compton Airport under the guidance of RRS members Waldo Stakes and Dave Nordling.

The Compton Comet team presenting to the membership

The rocket is a 75% ethanol & liquid oxygen bi-propellant rocket with a regeneratively-cooled engine. The engine is a surplus XLR-11 which should produce roughly 1,500-lbf of thrust, and was originally used in a group of 4 to power the Bell-X1 (the first aircraft to break the sound barrier). The rocket is estimated to reach an altitude of 20,000 km and will use a 2-parachute dual deployment recovery system.

THE FUTURE OF IN-PERSON RRS EVENTS

Members discussed the likelihood of in-person RRS events like the Symposium and meetings at the Gardena Community Center in 2021. It mentioned that the Symposium typically takes between 90 to 120 days to prepare, and it would be unlikely that the RRS would host one before spring 2022. There was a bit more of an optimistic outlook on the monthly meetings with a tentative goal set for a return to the Community Center in August (pending COVID restrictions).

MTA PERMANENT BATHROOM STATUS UPDATE

Designs and plans for the permanent bathroom structure at the MTA have been the main focus of the ongoing, twice-monthly meetings of the RRS Executive Council. Frank updated the membership on the current status of the project, which has gone through several iterations. Currently, RRS member Wilbur is working with professional drafters to get precise designs on paper – including model numbers for things like toilets and water heaters. A precise, written design will help the society get a final product that matches expectations.

The current plan is to build 2 or 3, 20-foot containers with 2 bathrooms each or 1 bathroom and 1 shower. These will be transported to the MTA and installed on concrete plinths which drain to a concrete septic tank and leach field. Water will be supplied by a well and stored in a tank installed on top of the bathroom or a nearby storage container. The bathroom facility is planned to be located southeast of the Dosa building, alongside the existing storage containers.

RRS BY LAWS

The RRS Executive Council has reviewed the recommended changes to the By Laws provided by the 2020 constitutional committee. Following are the By Laws as agreed to by the 2021 RRS Executive Council:

2021 RRS By Laws

LAUNCHING & STRUCTURES

Richard Dierking raised a question regarding the new structure being built on the Polaris land adjacent to the RRS site, and whether it must be considered an occupied structure during launch testing at the RRS site. This prompted a lively debate about the nuances of the regulatory framework around rocket activities in the Mojave desert, with several members voicing their opinions.

Safety of all personnel must be the #1 priority during activities at the MTA & communication between between the RRS, FAR, and Polaris is the best way to ensure that. Concurrent operations at adjacent properties are avoided when possible, and the RRS maintains relationships with our neighbors so that the Pyrotechnic Operator in charge is in contact with & can ensure the safety of personnel at adjacent property when operations overlap.

NEXT MONTHLY MEETING

The next RRS monthly meeting will be held virtually on Friday, June 11th at 7:30 pm pacific time. Current members will receive an invite via e-mail the week of the meeting. Non-members (or members who have not received recent invites) can request an invitation by sending an email to:

secretary@rrs.org

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,

president@rrs.org


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.