September 2021 Virtual Meeting


by Keith Yoerg (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.

Screenshot of discussion during the monthly meeting

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.

MASA logos – Tangerine Space Machine is named after a craft brewed beer local to the Michigan area

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.

MASA presenting a great photo of nighttime work at the MTA to the members at the September meeting

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.

Improvements the MASA team hopes to implement

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.

PERMANENT BATHROOM

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

View from inside the container with the doors and vent windows installed

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.

Several of the 3D printed fin alignment jigs

MISCELLANEOUS DISCUSSION

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:

secretary@rrs.org

Please check your spam folders and add secretary@rrs.org to your email whitelist to make sure you receive the invitation.

MTA Launch Event, 2021-04-10

by Keith Yoerg (RRS Secretary)


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.

Activity around 9:30 am at the MTA – prep work ongoing for CTRL+V (left) and Solar Cat (right)

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.

Launch of USC RPL’s CTRL+V, the smoke took a strange path up the rail faster than the rocket!

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.

LUMINEER (BPS.space)

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.

Launch of Lumineer from BPS.space

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 Gas Guzzler 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.

Launch of Wolfram Blume’s Gas Guzzler, it’s so calm the flag on the vertical test stand isn’t waving!

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.

Keith Yoerg’s Charlie Horse seen through the smoke of launch – the camera was tipping over!

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.

Bill Inman’s Solar Cat takes to the skies for it’s 2nd launch at the MTA

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 remains of the “Space Crater” – not covered in raw egg!

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.

No smoking sign added to the covered propellant loading area by Larry

CONCLUSION

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.

October 2020 virtual meeting

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.