August 2020 virtual meeting

By Dave Nordling, Reaction Research Society


In the absence of our secretary, I took a few notes from the meeting. This is what I recorded. Contact the RRS secretary for updates and corrections.

The Reaction Research Society held its monthly meeting by teleconference on August 14, 2020. Our monthly meetings are always held on the 2nd Friday of every month. We’ve had a lot of success with holding our meetings remotely and we will likely continue for the next coming months to continue our commitment to safety in light of the pandemic. Our membership is in regular contact with our community which has allowed us to promote and hold events including our first launch at the Mojave Test Area (MTA) on July 25, 2020. You can read the details in the firing report posted on this website.

Our members are doing well and thus far no one has reported being infected with COVID-19 which we hope continues to be the case. Frank is in regular contact with the Los Angeles Police Department’s (LAPD) Community Safety Partnership (CSP) but under current circumstances, the next school event may not be until next year. Options are being considered on how to continue our educational programs while maintaining social distancing.

The August 2020 RRS meeting held by teleconference.

REVIEW OF THE 7/25/2020 LAUNCH EVENT OPERATIONS

The first topic was the recent launch event we held on July 25th at the Mojave Test Area for the first time since the start of the pandemic. We had some difficulties in operating under the summer heat (106 Fahenheit at the peak) but this is nothing unusual for this time of year. Many of us were well prepared for the hot sun with our hats, sunscreen and iced beverages and chilled water. We also did a good job of watching out for each other. Still, the heat was responsible for leaving all but one of the micrograin rockets downrange. It also underscores the importance good planning, coordination and putting safety over all other considerations. We had several mis-fires which we were able to resolve, but maintaining discipline during the event proved to be a larger challenge. The launch protocols will be explained more thoroughly in the next safety briefing. The meeting highlighted that every member and pyro-op attending the event holds a joint responsibilty for the safety of all and it starts with self-discipline and patience by all.

Getting the beta rocket ready in the launcher on 7/25/2020 and setting the camera

We also discussed proper protocols such as announcing the pyro-op in charge well before the event and the necessity of providing detailed information about the intended operations to the pyro-op in charge in advance. Most of the planned projects were well understood as they were micrograin rockets and the previous hybrid rocket attempted at the last launch event.

DATA REVIEW OF THE STANDARD ALPHA FLIGHT OF 7/25/2020

The only micrograin rocket to be recovered from the launch event of 7/25/2020 was the standard alpha with plain steel nozzle. John Krell has been developing progressively better and more powerful avionics payloads designed to fit the narrow confines of the RRS standard alpha payload tube. John was able to spot and recover one of his payloads and process the flight data captured that day. The avionics payload was intact after being extracted from the desert floor including the solid-state data chip. John was able to recover the data and accurately reveal the huge acceleration of the RRS standard alpha with unprecedented accuracy. A peak acceleration of 114 G’s was recorded at roughly 0.3 seconds just before tail-off and burn-out at 0.4 seconds from launch. I was able to screen capture his plot below.

John Krell’s presentation of the data from the one recovered alpha ( to date).

The second plot shows the velocity derived from the accelerometer readings in the half-second which captures burnout at 0.4 seconds. Burnout velocity was measured at 670 feet/second which is consistent with prior data and trajectory predictions. The alpha is subsonic but travels at substantial speed from the swift acceleration. Given the high air temperature that day, 106 Fahrenheit, the speed of sound was 1165 ft/sec. The altitude of burnout was determined to be 130 feet which is consistent with prior flight data and high speed video footage.

Trajectory plot of the standard alpha flight from 7/25/2020

The third plot was made for the whole flight of standard alpha from the 7/25/2020 event from launch to impact at 35 seconds. Given the roets were impacting 2000 to 3000 feet downrange, the sound delay matches with the time to impact witnessed in the observation bunker. The maximum altitude was just over 4,400 feet based on the barometric pressure measurements using the 1976 standard atmosphere model. Base atmospheric pressure reading at the start of the flight shows the elevation of alpha launch rail platform is 2,048 feet.

Trajectory of the standard alpha flown on 7/25/2020

John Krell has really accomplished something with these custom avionics packages. He has been mentoring some of our other RRS members and the society encourages other members to build and fly their own payloads to spread the knowledge.

John Krell and Bill Behenna discuss avionics payloads

The society hopes to recover the other two alphas and the beta for further data analysis. Both of the unrecovered alphas from this last launch event had ceramic coated nozzles which should not erode. This should result in a more ideal performance as the throat area will not open up. The actual effect of this design improvement can best be assessed with recorded flight data. Also, we hope to compare the trajectory of the four-foot propellant tube with the standard length. Lastly. if the beta is recovered with recorded flight data, we may be able to assess its performance in unprecedented detail. The society hopes to report this flight data soon.

IMPROVEMENTS TO THE NITROUS OXIDE FILL/DRAIN MANIFOLD

The failure to launch the second build of the hybrid rocket was discussed at the August 2020 meeting. After discussing the launch procedures and corrective actions followed during the attempt to launch the nitrous oxide hybrid at the MTA with Osvaldo (the Level 1 pyro-op in charge) and racing experts at Nitrous Supply Inc., Huntington Beach, California, the cause of the fill valve’s failure to open became clear.

nitroussupply.com

In the racing industry, these normally-closed direct-acting solenoid valves are commonly used to open the flow of stored nitrous oxide bottles against the full supply pressure in the storage bottle. These are called “purge solenoid valves” among racers because it is this solenoid valve that opens the flow of nitrous oxide which displaces or purges out the air in the engine lines during the race. Buying these 12-volt DC high pressure solenoid valves from racing suppliers is much cheaper given they are made in greater numbers for the racing industry. (~$120 each versus $400+ each from reputable solenoid valve manufacturers).

In researching common designs for normally closed (NC) solenoid valves, the excessive heat of that day simply created too much inlet pressure against the internal valve seat for the electromagnetic solenoid coil to overcome and open the flow path. 1000 psig is likely the limit to reliably open these valves according to advice given by Nitrous Supply Inc. who has decades of practical experience at racing tracks around the country using purge solenoid valves for an application nearly identical to the needs of hybrid rocketry fill and drain operations. The ambient temperature at the MTA on launch day was creating a bottle temperature of 1400 psig accordling to the bottle pressure gauge and the separate pressure gauge in the manifold when the bottle was opened. This is well above the 900 psi recommended pressure range seen by marking on the gauge. The bottle, valve body and fittings are rated for these higher pressures, but opening mechanism of the solenoid valve was not.

A color-coded example of direct-acting normally closed solenoid valve is below. Blue shows the high pressure fluid path which is holding the seat down along with some assistance from an internal spring only for low inlet pressure conditions. With current applied to the electromagnetic solenoid (Orange), it pulls up on the moving armature (in red) which then allows the fluid to slip past the seal and through the flow control orifice when commanded open. Only a slight amount of movement is necessary to lift open the valve. However, if the fluid inlet pressure is too great, the solenoid can not provide enough force to lift and open the seal, therefore the valve stays shut.

Example of a direct-acting normally closed (NC) solenoid valve courtesy of M & M International (UK) Limited with color added to distinguish key parts.

To understand the relationship between pressure and temperature of the nitrous oxide you must consult the vapor pressure curve for nitrous oxide. This set of data points spans between the triple point and critical point of any pure fluid. NIST provides accurate data to generate such a curve.

webbook.nist.gov

nitrous oxide (N2O) liquid state properties, HTML5 table output from Web-book NIST.gov website
Nitrous oxide (N2O) vapor phase properties, HTML5 table output from Web-book NIST.gov website

The critical point of any pure fluid is where the distinction between gas and liquid phases disappears. This is not necessarily hazardous but it does mark a fundamental change in fluid behavior. The critical point of nitrous oxide (N2O) is 1053.3 psia and 97.6 degrees Fahrenheit according to Air Products company literature. This means the nitrous oxide conditions in the bottle at the launch (1400 psig as read on the gauges with an fluid temperature of 106 Fahrenheit or more) was well in the supercritical range, but again, this is only hazardous if the pressure vessels and plumbing connections aren’t able to safely contain the pressure. If the solenoid valve could have been opened, the pressure drop would have returned the supercritical fluid back to normal conitions and would flow dense liquid into the rocket when the fluid naturally chills down from the expansion.

Both the bottle pressure gauge and the manifold pressure gauge read excessively high on that hot summer day.

Keeping the bottle pressure below 1000 psia means controlling the external temperature of the bottle to a lower temperature. Below is a tabulation of state points along the vapor pressure curve for nitrous oxide (N2O) for common ambient temperatures. You can see that small shifts in ambient temperature can greatly affect the vapor pressure of the pressurized liquid. Keeping nitrous oxide under pressure is the key to retaining its denser liquid state. As long as the tank pressure is above the vapor pressure at that fluid temperature, you will have a liquid phase in the tank. If the pressure on the fluid drops below the vapor pressure, the liquid will begin to boil away.

  • 30 F, 440.05 psia
  • 40 F, 506.63 psia
  • 50 F, 580.33 psia
  • 60 F, 661.71 psia
  • 70 F, 751.46 psia; liquid density 48.21 lbm/ft3, vapor density 0.1145 lbm/ft3
  • 80 F, 850.46 psia
  • 90 F, 960.09 psia
  • 97.6 F, 1053.3 psia; density 28.22 lbm/ft3, CRITICAL POINT
  • Molecular weight = 44.01 lbm/lb-mol
Vapor curve for nitrous oxide over ambient temperature ranges

At first, it was thought that there wasn’t sufficient current from the lawnmower lead-acid battery we use. The summer heat can cause batteries to fail, but even after switching to a car battery, the failure to open was the same. Having a 12-volt solenoid requires greater current to actuate the solenoid valve, but it is a common standard for automotive grade parts which can be less expensive yet reliable. A current draw of 15 Amps over the long cable runs of a few hundred feet can be taxing to the firing circuit battery. This was not the cause of the problem, but it is a regular concern making sure sufficient voltage and current is available to both ignition and valve control.

To exclude outright failure of the solenoid valve, Osvaldo brought the unit home, allowed it to cool to room temperature then dry-cycled the valve from a battery to see if it still actuated. This simple test was successful and the filling valve in our nitrous oxide manifold continues to operate. At the next launch attempt, we will be prepared to chill the nitrous oxide supply bottle with an ice bath if necessary as was originally suggested at the prior launch event. Keeping the bottle pressure in an appropriate pressure range for fill operations is dependent on controlling the fluid temperature (60 to 90 F) under extreme heat or cold environments.

In researching purge solenoid valves, a second 12 VDC normally-closed valve was found and purchased. Nitrous Supply Inc., was out of purge solenoid valves but offered many alternative suppliers in the Los Angeles area. After some searching, I selected a high flow purge solenoid valve sold by Motorcycle Performance Specialties (MPS) Racing in Casselbury, Florida, for the purge solenoid valve used for venting our nitrous oxide manifold. The control panel is already equipped with the second command channel to open the vent from the blockhouse should it be necessary in launch operations. A schematic illustration is provided in this article.

mpsracing.com

Normally-closed 12 VDC purge solenoid valve from MPS Racing in Florida used for nitrous oxide applications including car and motorcycle racing.

The previous drain solenoid valve equipped with the nitrous manifold I bought was not deisgned for the full bottle pressure in the manifold so it quickly failed during initial checkouts. A manual valve was used in its place to carefully bleed out the remaining pressure in the line after the main bottle valve was tightly closed. This second solenoid valve will be used for draining the nitrous in the event of a launch scrub. Although the Contrails hybrid motor already has a small orifice and vent tube at the head end of the nitrous tank to provide slow release of pressure buildup, it is better to have a remote option to quickly depressurize the vehicle if the need arises.

Fill, drain and firing circuit for a Contrails hybrid rocket motor

With some re-plumbing of the nitrous oxide manifold to include the new vent solenoid, a soap-bubble leak check would be needed to prove the system before use. Given the significant overhanging weight of two solenoid valves, it may be wise to mount both valves on a separate plate structure to avoid excessive bending loads on the bottle connection. Design changes like this will be considered in preparation for the next launch event.

PYROTECHNIC OPERATOR TRAINING SESSION BY FRIENDS OF AMATEUR ROCKETRY

Mark Holthaus of the Friends of Amateur Rocketry (FAR) organization is offering an online training session for those interested in becoming licensed pyrotechnic operators in the state of California. The event requires registration on the FAR website and a fee paid to FAR ($10) to attend this two-hour introduction to the licensing and application process to be held on August 26th.

Friends of Amateur Rocketry website for indicating interest in pyro-op classes

Amateur rocketry in California is controlled by the same laws governing fireworks which require licensing by a state exam. The application forms and guidelines are available through the Office of the State Fire Marshal in the state of California (CALFIRE).

https://osfm.fire.ca.gov/divisions/fire-engineering-and-investigations/fireworks/

This training course for pyro-op applicants is another example of FAR and the RRS partnering to help the cause of amateur rocketry. The RRS, FAR and Rocketry Organization of California (ROC) last year met to create a joint set of recommendations to help CALFIRE improve the definitions used to govern amateur rocketry when CALFIRE they were seeking input from rocketry organizations. It is to the mutual benefit of the whole rocketry community and the public that there be more licensed pyro-op’s in amateur rocketry to both increase awareness of state laws and improve the culture of safety in our hobby and professions.

This FAR training course only serves to provide applicants with basic guidance on how to begin the application process and prepare to take the examination. Members of FAR, the RRS, ROC and any other amateur or model rocketry organization are welcome to apply. Several members of the RRS have already applied as the society continues its campaign to grow our ranks of licensed pyro-op’s at all three levels.

Completion of this training course does not substitute for any part of the pyro-op application process set by CALFIRE. As each applicant is required to pay their own fees including fingerprinting, they must also provide five letters of recommendation from licensed pyro-ops at or above the level of license being sought. After this class, each applicant must formally request these letters from state licensed pyro-ops in writing. For a licensed pyro-op to offer a letter of recommendation to an applicant, they must be willing to endorse their skills, knowledge and character to the state of California based on their personal experience with that individual. This is done through active participation at launch events through rocketry organizations having licensed pyro-ops leading their operations. Apprenticing, studying and attentiveness are all ways that a pyro-op can get to know an applicant personally and thus build confidence that the applicant is ready to have the responsibility of being licensed in rocketry. A letter of recommendation is given solely at the discretion of the licensed pyro-op which means their standards and expectations may vary significantly from others. It is important to establish a working relationship with both the society and the specific pyrotechnic operator over several projects to demonstrate skills and learn best practices through active participation.

As the RRS has more licensed pyro-ops than FAR at this time, this training course will be successful if both organizations support it. Some of the RRS pyro-ops have already offered their support as this means more people will need to become active with the RRS and conduct their projects at the MTA.

ROCKET LABORATORY AT THE COMPTON AIRPORT

Keith Yoerg announced that there is a tentative plan to create a rocket laboratory in a hangar at the Compton Airport, Although, the hangar will be used from time to time to store or service light aircraft, there is a great deal of working space which will help the RRS continue their liquid rocket project already underway. Several members of the RRS are also active with civil aviation and are members of Chapter 96 of the Experimental Aircraft Association (EAA 96). The EAA has generously supported the RRS over the last two years and we hope to continue and expand this partnership.

NEXT EVENT AT THE MOJAVE TEST AREA

The RRS has been planning the next event at the Mojave Test Area which will be dedicated to repairing some of our facilities including the adjustable rail launcher damaged in solid rocket launch explosion in August 2019. The consensus at the meeting was that we should not to return to the MTA for a formal launch event until the seasonal temperatures decrease from the excruciating desert summer. October 3rd was selected for this work event, Our hope is the weather will be cooler and we can accomplish more on that day. We may also take some time to search for more rockets planted downrange from past launch events.

The RRS may also conduct a few static firings or even a launch if member projects are ready. All such proposed hot-fire and launch activities must be proposed to the RRS president and the selected pyro-op in charge for that day. Some of our member projects such as Wolfram Blume’s Gas Guzzler two-stage ramjet and my second-build of the high-powered hybrid rocket are both still works in progress and may be ready for the early October launch date. Larry Hoffing has been working on an improved solid motor chemistry which he may want to test at the MTA.

The RRS is available for private events before that time, but one must make their request to the RRS president as usual. Some have indicated interest in returning to the site for just a few hours to recover more rockets downrange. Its our policy that at least two members be present for any excursions to the MTA and the RRS president must be notified in advance.

IN CLOSING

Some topics were not able to be covered including the overview of the new RRS Constitution as it gets ready for administrative membership review. Also, facility improvement plans at the RRS MTA including new restroom facilities and blockhouse should be discussed.

The next RRS meeting will be held by teleconference on September 11, 2020 as it is unlikely we will be permitted to return to the Ken Nakaoka Community Center by then. We hope everyone continues to stay safe during these days of the pandemic and try to stay in touch as we are planning another event at the MTA for October 3, 2020.

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

secretary@rrs.org


July 2019 meeting

Dave Nordling, RRS Secretary


The RRS held their monthly meeting on July 12, 2019, at the Ken Nakaoka Community Center in Gardena. We had a very large turnout with over 26 people coming in to see the three different presentations we had and catch up on the latest news.

After our reading of the treasury report, we had a special announcement of the induction of five new administrative members to the RRS. Our society is growing and this is in large part to the great participation we’ve been having and the dedication of the many talented people at the RRS.

Larry Hoffing gave us a short summary of the UCLA Rockets project he supervised at the RRS MTA. This Wednesday, July 10th, event was the first since the pair of earthquakes that rattled the nearby town of Ridgecrest in the Mojave. The RRS is happy to report none of our structures had any significant damage and the MTA is very much ready to operate.

We next discussed the upcoming launch event at the MTA tomorrow with Operation Progress in Watts with the LAPD CSP. We’ll have several alphas and a beta launch. We also plan to have an alpha with a parachute recovery system put together by new member, Kent Schwitkis and his friend Brian.

RRS vice president, Frank Miuccio, has started a new educational program this week with the students of Boyle Heights. There will be 10 teams launching their rockets from the MTA in September.

RRS alpha outfitted with a 36-inch parachute
Two alpha payload tubes with the nose cone and couplers installed. Reused parts from recovered alpha rockets.

Our first presenter was Kent Schwitkis who brought several of his students from Compton College to our Friday night meeting. Kent is a member of the Sierra Club and Ski Patrol and has many years of experience with wilderness survival and first aid. His presentation outlined the important of planning for many kinds of potential emergencies. One of the important results from this discussion was the need for the RRS to form a safety committee to begin preparing emergency plans and establish contact with the regional authorities in preparing to handle serious emergencies if the need would ever arise.

Kent Schwitkis and Waldo Stakes before the July 2019 meeting

The second presenter we had at the meeting was Sam Austin, a senior at MIT. Sam presented his two-stage solid rocket design to reach the von Karman line.

Sam Austin (right) presents his booster and second stage design for his solid rocket

Sam also detailed the kerosene-LOX liquid rocket design that was test-fired at FAR in January 2019. Although the test was short (3 seconds), his results were impressive and his injector survived intact..

Sam’s liquid rocket injector which was modified for 1500 lbf of thrust

The last presentation was by RRS members, Jack Oswald and Cooper Eastwood. They have been steadily improving their solid motor design and have fabricated their improved motor based on prior tests. Their goal is to reach the 50,000 foot altitude limit at the RRS MTA on July 20th. His “50 for 50” rocket is 12 feet tall and 5-inches in diameter built entirely from scratch. The launch is to be timed with the 50th anniversary of the Apollo 11 moon landing.

Jack and Cooper detail the progress they’ve made and their solid motor ready for flight from the RRS MTA on July 20th.

The solid rocket holds 30 lbm of APCP propellant with an estimated burn time of 3 to 4 seconds generating an impulse of 7000 lbf-sec. The rocket fully loaded is 84 lbm and should reach a peak acceleration of 30 G’s and a burnout velocity of Mach 2.5 as it reaches 50,000 feet.

A 100-foot drogue streamer will deploy from the recovery system followed by a 9-foot Apollo 11 replica parachute at 2000 feet. The flight events are driven by an upgraded classic flight computer from Eggtimer and an RRC3 dual deployment system from MissileWorks. The von Karman nosecone is 3D printed and the aluminum fin can was rolled onto the aluminum body to be painted in polished black and white pattern of the Apollo 11 vehicle.

The RRS looks forward to the successful flights of Sam and Jack’s rocket from FAR and the RRS MTA, respectively. Both will be on the 50th anniversary of mankind’s greatest achievement on July 20th.

If there are any questions or corrections, please contact the RRS secretary. The next meeting of the RRS will be August 9, 2019.

MTA launch event, 2018-06-02

The RRS held a launch event at our private Mojave Test Area (MTA) with the students and staff of UCLA on Saturday, June 2, 2018. The event was overseen by our pyro-op, Jim Gross, with me serving as his apprentice. It was a good day for rocket launching despite the 100 degree temperatures that day. The winds were very low and almost still at certain times.

The horizontal thrust stand was fit checked at the RRS MTA concrete slab. All footplate holes aligned with the 1/2″-13 female anchor bolt holes. The load cell blocks mated up to the adapter plates. Concern was raised about the horizontal stability “wagging” of an alpha rocket if it were fired in the adapter as is. Osvaldo started a design to create an extension on the thrust stand which will better retain the rocket from excessive side loading.

RRS horizontal thrust stand passes fit check at the MTA, new primer coating added for rust protection

UCLA was completing a quarterly course in rocketry which featured the hard work of five student teams building their own amateur rocket using commercial F-class motors of different types.

UCLA students pose at the RRS MTA on June 2, 2018

The RRS was able to inspect each one of these model rockets and ask questions of the team members about its construction and the unique aspects used in their payload and vehicle design. Each of the teams ran flight stability tests at the UCLA wind tunnel to validate their design. Each rocket was fired from a rail launcher and a commercial firing circuit under the supervision of the pyro-op.

Six rockets from five teams at UCLA on display in the group photo (6/2/2018)

Before the flights of the student rockets, a test rocket was flown to check the wind speeds. Results showed low winds so the team flights proceeded. The winds at the launch site in the desert were very low throughout most of the day.

UCLA’s demo rocket to test winds before team flights.

UCLA prepares their custom rail launcher for their model rockets

One team attempted a two-stage rocket using a D-class motor in Stage 2. Results from all rockets were largely good. All were recovered and some were able to be relaunched.

UCLA’s Team Sharky prepare their rocket “Bruce” for his maiden voyage.

Each rocket flew an egg as a payload with a parachute recovery system. Each rocket also included a commercial altimeter chip which relayed the results to display on a cellphone application. Altitudes ranged from 1600 to 2400 feet.

UCLA also was static testing a hybrid motor adapted from commercial products to a design of their own. Two vehicle systems were built and alternately tested with replaceable HTPB-based fuel grain modules. UCLA brought a few nitrous oxide tanks to replenish their oxidizer supply. All seemed to go well, but the results were not good enough to proceed with a flight test as originally scheduled.

Dr. Mitchell Spearrin and Jim Gross oversee the hybrid rocket static firing procedure at the RRS MTA, 6/2/2018

UCLA’s Anil Nair prepares the hybrid motor for static firing at the RRS MTA, 6/2/2018

UCLA’s first of three hybrid motor firings, 06-02-2018

Results from first hybrid motor firing left a white residue around the outside of the nozzle

UCLA did buy two of our RRS standard alpha rockets which were custom painted in the blue and gold colors of the UCLA Bruins. At the end of the long day, UCLA opted not to fly their two RRS standard alphas and save them for another flight. The RRS and UCLA discussed flying an altimeter chip in a vented payload tube on the next UCLA flight of the RRS alpha.

Two RRS standard alpha rockets for UCLA

The RRS already had the micrograin propellant mixture ready so we proceeded with a flight test of our own RRS alpha rocket. We had plenty of daylight left in the summer month of June. For those that stayed at the MTA into the late afternoon, the RRS did conduct a first test of a payload recovery system in a standard RRS alpha rocket. This system was built by RRS president, Osvaldo Tarditti.

Jim Gross and Osvaldo Tarditti load an RRS standard alpha with parachute payload into the launch rails

An RRS alpha with its payload being installed.

Instrumented RRS alpha in the launch rack. A manual switch with red flag is used to arm the system before launch. This keeps the battery from depleting while waiting to launch.

The payload timer is started when the rocket lifts out of the launch rails and the pin is pulled out by the yellow wire tied off to the launch rails.

Despite some problems initializing the payload one the first attempt at the launch rack, the rocket was successfully reset, reloaded and flown. The deployment of a parachute from inside an RRS standard alpha rocket’s payload tube with a successful recovery was the only objective of this flight.

In the still winds, the rocket didn’t drift very far from due west and the orange parachute was very visible against the clear blue afternoon skies once it reached lower altitudes. The alpha rocket booster portion was recovered, but the lanyard holding the nosecone and payload segment tore loose on deployment and was not recovered.

Lanyard failure lost the payload and nose with the timer circuit inside, 6/2/2018

Also, the orange parachute did show signs of localized overheating and melting from the 1-gram black powder ejection charge used to deploy the parachute.

scorching of the parachute from the ejection charge; parachute was still effective

The parachute did deploy fully and significantly slowed the descent of the rocket booster. With the low winds, the rocket did not drift very far downrange and was easily recovered 50 feet from the roadside going out west from the MTA

Osvaldo kneels behind his RRS standard alpha parachute system successfully flown at the MTA on 6/2/2018

I took several photos of the assembly and loading process. Osvaldo has promised to explain the full details of his parachute system and deployment timer. The RRS will definitely reattempt parachute recovery with our alphas and hope to fly again at the next event.

As a final step, we make sure to burn off our residual propellants. Jim Gross set this up near the launch pad and used the firing system already in place at the bunker.

Pyro-op Jim Gross prepares to safely dispose of residual micrograin propellant at the RRS MTA

Residual micrograin propellant safely burns up at the end of the day

At the end of the propellant burn-off, the smoke cloud lazily lingered as it rose away from the site. Taking several minutes to do so, this was a very visual reminder of just how favorable the winds were that day.

minutes later, a spent micrograin propellant smoke cloud slowly drifts away in the low winds at the MTA

If there is anything I have missed or misstated, please let me know.
secretary@rrs.org

The next monthly meeting is this Friday, June 8th at 7:30PM. Discussion of the UCLA event and our next event with LAPD CSP will certainly be on the agenda.