The Reaction Research Society held it’s monthly meeting by teleconference on Friday, October 8, 2021. Some of our members were on travel, but the those in attendance were able to discuss several important issues.
The USC RPL static fire event on 9-26-2021 was safely conducted but ended in a explosion and fire which was ably contained. This was a good example of careful preparations and good management of the people present for the event. A firing report has been posted for this event. Osvaldo Tarditti was the pyrotechnic operator in charge that day.
UCLA had requested the use of the MTA on 10/16/2021 for their next liquid rocket engine test. The MTA was already reserved for Bill Claybaugh’s solid rocket flight that same day and in the days leading up to the event. Dave Nordling was the pyro-op in charge, A firing report for this event will be posted,
UCLA is planning to hold their conceptual design review (CoDR) on 10/22/21 for the next iteration of their liquid rocket. RRS members Dave Nordling and John Krell plan to attend.
Wolfram Blume was on the call and said he was eager to return to the MTA for a second flight attempt of the Gas Guzzler ramjet. With the summer heat gone, he hopes to return at our next launch event which is still being planned. It is hoped that the society can continue their streak of having at least one MTA event per month as we have done since the start of 2021.
The restroom container was purchased and brought to the Compton Airport for interior construction. This 20-foot high cube has a 9.5 foot ceiling and should be able to have two individual rooms with toilet and sink, one of these to have a shower stall. Osvaldo had drafted a floor plan and this was approved by the council. The society will be meeting at the Compton Airport on Saturday, October 23rd, for a late morning barbecue and an in-person discussion of the materials needed to get the restroom interior built. All members are welcome but please notify Keith, Wilbur, Xavier or Dave Nordling if you’re coming as they have access to the airport.
There was some discussion about the septic system and leach field. It is important to maintain an appropriate distance from any nearby water wells, one of which is on Polaris Propulsion property. Sufficient clearance exists based on measurements made and EPA guidelines. The leach field will be positioned to drain away to the north.
The society is considering buying a concrete septic tank but RRS member Wilbur Owens may have a plastic septic tank already available for the society. Some members feel a concrete septic tank will last longer and be less likely to leak. The council is still debating this feature and should render a decision soon.
The society also discussed the water supply to the restroom container and the supporting structure needed to hold a tank on top of the container. There are many important facets to this infrastructure addition which must be weighed carefully.
Nominations for RRS executive council offices will be held at next month’s meeting, November 12th, 2nd Friday of the month at 7:30pm. An election chairman will be selected beforehand and this person must be an active member not holding office nor running for office. A special email address will be set up for the election chairman to gather votes from our active administrative and lifetime members. Results to be announced at the December 10th meeting and new terms to start January 1, 2022.
For any questions, please contact the RRS secretary.
The latest meeting of the Reaction Research Society took place Friday, September 10th and had 16 attendees, including several members of the University of Michigan Aeronautical Science Association (MASA) team which conducted a long campaign of testing at our MTA site last month. After brief hellos & a short discussion on updates to this website, we got the meeting rolling with a presentation from the MASA team debriefing us on their August tests.
PRESENTATION ON MASA CAMPAIGN AT THE MTA
4 members of the MASA team who were present for the long campaign of testing at the MTA site were at the meeting and provided a presentation detailing how the nearly 2 weeks of work went for the team. A detailed write-up from RRS member Dave Nordling who was on site assisting for some of that time is available here.
While the end goal of conducting a hot fire test was not accomplished, there was a ton of great work and learning opportunities for both the MASA team and the RRS. The first challenge for the MASA team was in driving their equipment all the way from Michigan to Southern California. Unfortunately, they had some equipment suffer damage during the trip when their smaller “Ground Support Equipment” (GSE) trailer broke through the plywood floor of their larger travel trailer. This required them to stop in Texas and complete repairs to the travel trailer before continuing on to the MTA site.
Once at the site, the MASA team set up a 2-shift schedule (9am – 6pm and 5pm – 12am) effectively working 18-hour days to conduct the activities required for their tests. Many of these tasks took a lot longer than the team had anticipated, in particular with the supply and delivery of the gas & cryogenics needed. The MASA team was originally in contact with Airgas, but their communication was with the office closer to their home in the Midwest and not the Southern California branch. Ultimately sorting through those issues proved to be too difficult to secure a delivery while the team was at the MTA, but fortunately they were able to work with Praxair to secure a supply of the gas and cryo.
Once the gas and cryogenics were at the site, the team was able to complete pressure tests of the fuel side of the system, and were ultimately able to perform 2 coldflow tests through the entire system near their target pressures. These tests revealed many more areas for design improvements that the team hopes to implement, including reducing fittings, changing the location of vents and drains, and possibly even replacing the LOx and fuel tanks.
This campaign goes down in the books as the longest to ever take place in RRS history, and proved to be challenging for both the MASA team and the RRS. Several society members graciously volunteered their time to help make this testing effort possible, and the experience revealed many ways that the society could improve our procedures to better support extensive tests like this. Namely: limiting the duration of a test period to no longer than 1 consecutive week, requesting that some members of University staff be on-site when these long campaigns take place, and requiring a longer notice time before approving this sort of test were all brought up by RRS president Osvaldo.
Progress is continuing on the permanent RRS Bathroom structure. Work on cutting holes for doors and windows has been completed on the 20-foot shipping container and delivery is expected imminently to the new work site at Wilbur’s hangar. The next stages of construction including adding plumbing, fixtures, and the doors and windows, and Osvaldo has already acquired some of these items to install
SEPTEMBER MTA EVENT & WORK PARTY
The USC Rocket Propulsion Lab (USCRPL) plan to be out at the MTA site from Friday, September 24th – Sunday, September 26th to conduct a static fire of an 8″ diameter solid rocket motor. The first few days will consist of prep work and the firing is planned on that Sunday. Several members including Bill Inman and John Krell indicated in the meeting that they have stepped up to the Yoerg Challenge and built model rocket kits to fly at the MTA. This will give us a great excuse to test out the new PVC wire rail launchers as well as the newly purchased Cobra wireless firing system.
In addition, the society has decided to use Sunday, September 26th as the date for our annual “Work Party” to perform maintenance and cleaning tasks at the MTA site. The expected tasks we would like to complete are:
Weld the plate on the vertical test stand
Removal of dry vegetation
Move drum of RP1 (from MASA testing) into one of the lockable containers
Fix the 2 broken latches on the Dosa Building roll door
Prep/measurements in area for new container bathroom
YOUTH ROCKETRY CLASS
RRS Vice President Frank updated the membership on the upcoming youth rocketry class in Boyle Heights with details on the schedule and overall plan. As opposed to 2 alternating classes, we will now be working with a single class of up to 30 students. The classes will run every Friday starting on September 24th, with a launch planned at the MTA site on November 13th. The plan is for each student to build their own Estes Baby Bertha kit and fly it twice on launch day. RRS Secretary Keith is currently working on 3D printing fin alignment jigs for the students, which will help in both teaching the students about that technology as well as properly installing straight & aligned fins on their rocket kits.
The end of the meeting consisted mostly of miscellaneous discussions around the various projects that RRS members are currently working on. Some of the highlights included John Krell’s new, very small (20x80mm) electronics board capable of collecting 7 channels of data onboard a flight, with over half of those channels at 500 Hz! Bill Inman updated members on the progress with his Solar Cat steam rocket, and there was a brief discussion of ham radio operations with Tom Hendricks sharing some of his wealth of knowledge in that subject. Overall it was a fun meeting with a lot of good discussion & participation from the membership.
NEXT MONTHLY MEETING
The next RRS monthly meeting will be held virtually on Friday, October 8th 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:
Please check your spam folders and add firstname.lastname@example.org to your email whitelist to make sure you receive the invitation.
The RRS held a launch event at our Mojave Test Area (MTA) on April 10, 2021, the day after our monthly meeting. COVID-19 still remains a threat so everyone continued to observe protective protocols – masks & physical distancing. For the first time in months, we had a day with great weather for launching rockets and we made the most of it! We had low-power, high-power, and experimental solid rocket launches, another launch of Bill Inman’s Solar Cat, the maiden voyage of Wolfram Blume’s Gas Guzzler, and a static fire of Larry Hoffing’s solid power motors. Osvaldo Tarditti was our pyrotechnic operator in charge.
CTRL+V (USC RPL)
Preparation for the first launch of the day: CTRL+V actually began the day before launch with motor integration and other preparation work taking place at the MTA site. On the morning of the launch, the team from the USCRPL installed the rocket on the launch rail, which was then raised into place south of the MTA’s vertical test stand. Wires running from the rail were staked to poles and hammered into the ground to provide additional stability for the rail. Several launch crew members can be seen prepping the rocket above, and a still image of the launch of the rocket can be seen below.
The rocket flew on a 6″ experimental rocket motor. A specific procedure was followed prior to launch, under the supervision of the pyro op, which included radio go/no-go call outs from several teams including tracking, avionics, and even a drone that took footage of the launch! All spectators and crew were in the bunker during takeoff at 11:04 am – ignition was prompt and rocket left the rail quickly and cleanly. The initial telemetry reported by the team indicated an altitude of over 11 km. Several members then went off on the daunting task of recovering the rocket from wherever it landed.
The next flight of the day came from BPS.space with the rocket Lumineer. This launch was conducted from one of the pads just west of the vertical test stand. The flight took place around 1:20 pm on a commercial Cessaroni “N” motor and was livestreamed to a reported 9,000 viewers on YouTube. The rocket utilized a “fly-away” rail guide to provide stability and eliminate the drag of rail buttons, which can be seen still in the process of falling from the rocket in the image below. The target altitude was 10 km, but telemetry was lost shortly after takeoff so the actual peak altitude was unclear after launch, and the rocket was not recovered for some time.
GAS GUZZLER (Wolfram Blume)
Wolfram Blume has been diligently making the pilgrimage to the MTA events over the last several months and the weather has been uncooperative for his chances of launching, but that finally changed in April! The maiden voyage of the GasGuzzler took place from the pad just west of the vertical test stand. This flight was conducted to answer several questions about staging during the flight – so the ram jet second stage was flown empty and only the first stage, commercial solid rocket motor was used to power the rocket. A slow-motion (10% full speed) video of the launch can be seen here.
The ascent of the rocket was smooth, validating the rigidity of the rocket’s design and the stability when empty. The data from onboard altimeters confirmed that the ram air entering the 2nd stage was enough to separate the 2 stages immediately (0.1 second) after motor burnout which occurred at 1,440 ft. The parachute for the booster stage deployed successfully and that stage was recovered without damage. The ram jet, upper stage utilizes a dual-deployment of a drogue parachute at apogee and main parachute at 1,000 ft above the ground. While each of these deployments were successful, the main parachute did not pull out of the deployment bag so the stage landed hard and damaged a few parts. Fortunately, the 2nd stage is not the final parts intended for the full flight of both stages so there will not be delays to the project to rebuild. Wolfram collected lots of useful data and plans to add a GPS tracker and other upgrades before his next flight. We all hope the weather remains in his (and all of our) favor!
CHARLIE HORSE (Keith Yoerg)
Up next was the 12th flight of Keith Yoerg’s rocket Charlie Horse. This was the first flight test of the LoRa GPS tracking boards discussed in previous reports. There are several difficulties with getting the units setup properly, not least of which being the frequent firmware updates required to pair the board with the mobile phone app (2 updates in as many months). Powering up the boards the night before would have helped eliminate these struggles, but a successful launch was still completed, a slow-motion (10% full-speed) video of the launch can be seen here, which was on a commercial Cessaroni I280-Smokey Sam motor.
One issue still to be resolved with the LoRa trackers is a setting within the Meshtastic mobile application which trades off tracking range for the speed at which new information packets are sent. The “medium” setting was used on this flight but for rocket flights it may be advantageous to reduce the range (which is purported to be up to 10 miles) in favor of more frequent location updates. More testing will be done on future flights in hopes of developing a cheap, simple GPS tracking available for rockets flying at the RRS.
SOLAR CAT (Bill Inman)
Bill Inman’s solar-heated steam-powered Solar Cat rocket took to the skies around 4:31 pm. While the weather was perfect for most of the projects, the light overcast that can be seen in the pictures above proved problematic for the solar heating required for the best flight. In addition by launch time, the solar collector was at its westernmost limit so no more heating was possible. At launch the water temp was 370 F and was at 130 psi.
The flight reached 41 mph speed and achieved a 60 ft altitude. While this was an improvement on the first Solar Cat launch at the MTA, with additional heating there could be even more impressive stats. While he can’t control the clouds, Bill hopes to arrive at the MTA site the night before a launch in the future to increase the chances of getting off a good test and launch before reaching our western limit of travel for the solar collector.
THE YOERG CHALLENGE (Dimitri Timohovich & Keith Yoerg)
With this being Dimitri’s last MTA event before leaving to Alaska for the summer, some other RRS members need to step up to the plate to keep the “Yoerg Challenge” alive. I have put out the call for more RRS members to build low-power rockets to fly at the MTA, and have left my 5-pad PVC launcher at the site for future launches. IT’S CHEAP, IT’S FUN, IT’S A CHALLENGE (and everyone is a winner)! What’s not to love? So get out there and build some model rockets!
The entrants this month included Keith’s Big Bertha, Baby Bertha, and Hi-Flyer XL rockets and Dimitri’s Space Crater – which carried eggs in honor of Easter this month. Fortunately, Dimitri’s wife had the foresight to hard-boil the eggs because his rocket took the “Crater” part of its name a bit too seriously (the remains are shown above). A few of Keith’s flights before the GoPro battery died can be seen here.
SOLID MOTOR TEST FIRE (Larry Hoffing)
Larry Hoffing had some experimental solid rocket motors ready to test fire, but with all the other activity going on at the site he took the time to install a new “No Smoking” sign on the covered propellant loading area (shown below). Once things were a little less active, Larry was able to affix the motors and perform a test-fire. While the burns were long, they did not produce much thrust and need to be improved upon before use in a rocket.
In addition to everything detailed above, one of the USC RPL members flew a high power rocket to earn her Level 1 certification with the National Association of Rocketry, and Dimitri flew his water rockets with his son.
This was by far the most active event at the MTA in the past year and was an exciting day for anyone who likes to see rockets fly! Our next launch date has not been decided upon, but we hope to have an event in May to continue hosting at least one event per month at the site.