August 2018 meeting

The Reaction Research Society (RRS) held it’s monthly meeting on August 10, 2018 at the Ken Nakaoka Community Center. We were very well attended with four new people including returning member, Jim French. I was unable to attend the meeting, but other council members gave me their notes.

The RRS meeting got a late start at 8:00pm. (Our starting time is supposed to be 7:30pm.) The agenda items were not covered in order, but the list of topics to be covered were as follows:

[1]
This was to be a discussion of the 2018-07-21 launch event that the RRS held at the MTA with LAPD CSP and the student group at Watts. The event was successful with both the student alpha launches and a few RRS member alphas with payloads. The event was summarized in a previous article. A few things could have been done better which will make future events go more smoothly.

A single, simpler briefing to the kids would have been more effective. The kids in the student classes do pay attention at the events (which is great) but the RRS is giving a lot of redundant information and a more concise presentation delivered by only the pyro-op will be far better than having three people talking at the same time.

Also, every person conducting a launch or hot-firing at the MTA must submit a detailed proposal to the pyro-op for review at least a week in advance and gain the RRS and pyro-op’s approval PRIOR to coming to the event. The RRS has a Standard Record Form available on this website under the Membership tab of the Homepage and under the subheading of Forms. This downloadable document gives members a basic framework for the detailed information they must provide to the pyro-op describing their project and its goals. The RRS encourages members to present their proposed projects at the meetings and be very detailed in any reports submitted to the pyro-op and RRS president. The RRS wishes to keep good records to benefit the society and future projects.

RRS – Membership / Forms / Standard Record Form

In the recent times, our pyro-ops have been very casual about this requirement and have been kind enough to review things on the spot, but this needs to change. The RRS used to be even more stringent on this requirement. The RRS requires advance preparation and there is no reason why this can not be done by all participants. The pyro-op is the single and solo authority for what is and isn’t done at the launch event. The pyro-op should be the most informed individual about what is going to be attempted at the MTA.

In future events, if the desire is to have the student launch event conducted first, it would be wiser to not conduct any events before the student launch. Having launch and hot-fire events declared, reviewed and scheduled days in advance will help make RRS events go more smoothly and safely. Years of experience at the MTA has shown that tasks ALWAYS take longer than planned and too much waiting can make coordination of large groups unnecessarily difficult. Therefore, having our coordinated events go off first without distractions from other planned activities will make it easier for our pyro-ops to conduct their duties and make our participants be more organized in their projects.

The extreme heat of mid-July made it very difficult to conduct operations but having the motorized cart to shuttle the pyro-ops to and from the launch site made a critical difference. Bringing ice in the summer is a necessity. I have learned this lesson well. Having everyone well prepared for the hot weather continues to be the best advice.

[2]
Chris Kobel who is a member of Rocketry Organization of California (ROC) shared some advice for pyrotechnic operators (pyro-op). Chris has been a pyro-op for over 10 years and is pretty active with amateur rocketry. Safety was the primary emphasis of his presentation. He also mentioned a key point of contact at the Office of the State Fire Marshall (OSFM) of California, Tom Campbell. Mr. Campbell is very important authority at the California State Fire Marshall’s office who can answer important questions. Chris and the other pyro-op members at ROC were also willing to counsel RRS members interested in becoming pyro-op’s.

The RRS was glad to have Chris give our membership a wealth of information. We look forward to working more with Chris and ROC in the near future as the RRS is expanding our roster of pyro-ops for our growing events.

[3]
Osvaldo’s flight telemetry from his alpha flight on 2018-07-21 was briefly mentioned at the meeting. It was good that the flight was successful that data was taken. Given the time constraints, he’ll give more details at the next month’s meeting.

[4]
Progress on the RRS alpha parachute systems and future attempts was to be detailed by both Osvaldo and Larry who each attempted a unique recovery system built into the small confines of the alpha payload tube. Again, insufficient time was available at this meeting and this event can move to next month.

[5]
Sam Austin gave a presentation of MIT’s solid rocket launch and his upcoming liquid rocket hot-fire. MIT’s solid rocket made from scratch reached an altitude of 33,000 feet as confirmed by dual altimeters. Sam provided a rough order of operations for their solid rocket grain making process and detailed their recovery. Sam is here in Los Angeles for the summer on his internship, but will return soon to MIT.

[6]
There will be a liquid rocket hot fire testing on August 18th at both the Friends of Amateur Rocketry (FAR) site and the RRS MTA. Sam Austin has been working on his liquid rocket motor to test at FAR, next door to the RRS MTA site. Richard Garcia has built a small liquid motor for what could become the RRS standard liquid rocket design. Our two members have agreed to share resources and the hot fire events will take place on 2018-08-18.

Both projects will use a nitrogen K-bottle as their pressurization source and will share a liquid oxygen dewar to provide the oxidizer to both of their engines. Richard’s liquid rocket motor will use a 75% ethanol and water mixture as a fuel, while Sam’s liquid motor will use kerosene as the fuel.

Sam and Richard have put a lot of work into these projects and we hope they have success. I plan to go out there to help document the event for a new posting to come shortly after.

[7]
The meeting was to discuss upcoming RRS launch events including the next one with LAPD. Frank has said that the next event with the LAPD CSP will be with the Boys and Girls Club. LAPD CSP is also working on setting up another school group in Watts for an RRS event. Specific dates were not yet set, but that information will be coming soon. We will post announcements of forthcoming launch events in the “Forum” section of this webpage.

[8]
RRS Instagram and YouTube account guidelines have been generated by Chris Lujan are being reviewed by the RRS executive council. The idea of creating an RRS media manager position was accepted by the council. The RRS is considering offering this new position to RRS members, Bill Janczewski and Alastair Martin, who both have put forth a great deal of excellent work for the society. The RRS executive council will vote soon to better our social media presence to help our outreach efforts and give our followers a better view into the society.

Richard Garcia shared access information with the executive council on the existing social media accounts that the RRS has including Facebook and YouTube.

The RRS executive council now has access to Instagram and will be sharing photos from events more easily and quickly with our public audience. I have already begun to load photos I’ve had from recent events. More of the RRS will be posting to Instagram very soon.

Subjects not on the agenda included:

[BONUS 1]
The RRS will start to hold special Saturday morning seminars for special topics that can be covered in more depth outside of our monthly meeting. These bi-monthly sessions will take some work to coordinate, but should allow more of our membership to enjoy the quality of talks that we have been privileged to enjoy. Jim French agreed to give the first of the RRS Saturday seminars at a date to be determined very soon. Jim was a member of the RRS 25 years ago and we’re happy he’s come back to join us. Jim also has the distinction of being a rocket engineer for over 60 years and worked on the Apollo program. This will be a great presentation to start this series.

[BONUS 2]
I have been able to get the top and bottom plates made for the RRS ballistic evaluation motor (BEM) which will be a key part of the SuperDosa project and the RRS having the ability to take accurate burn rate measurements at the MTA for future motors. I am thankful to Matt Moffitt of CNC Specialty Machining in Huntington Beach. I hope to have the cylinder piece in the RRS BEM machined soon. This will likely require lathe work. Osvaldo is also looking into getting this part made. It is my hope the RRS BEM can be completed by the next quarterly update of the SuperDosa project in October 2018.

Top and bottom plates for the RRS BEM just back from the mill.

I have heard that Jack Oswald is trying to get into testing his large solid motor with an improved design. The RRS may have more to present next month on this subject.

[BONUS 3]
I wanted to bring a special device I bought from Additive Aerospace called a fly-away rail guide. I was introduced to this device by David Reese of ROC. Although the RRS has a very effective box-type rail launcher at the MTA site which will remain our standard technique, I decided to attempt a new method of launching an alpha just to get a longer guided path on launch.

Additive Aerospace – fly-away rail guides

This device allows a rocket to be fired from a extruded aluminum rail launcher such as the one we have at the RRS MTA, but without having to permanently attach the round launch buttons to the rocket itself. A spring-loaded clampshell piece goes around the rocket with a launch button on either side such that the clamp is closed when the rocket is on the rail. As the rocket takes off, the fly-away rail guide goes with the rocket along the rail launcher until the buttons clear the rail and swing open releasing it from the rocket as it speeds away.

Fly-away rail guide from Additive Aerospace; custom-built for an RRS standard alpha rocket, shown in the open position.

These devices are intended for common model rockets of the standard metric sizes (38mm, 54mm, 76mm, 98mm). I had this rail guide customized to fit an RRS standard alpha rocket which is slightly smaller than the 38mm size at 1.25 inches in diameter. I hope to demonstrate the fly-away rail guide device with a loaded RRS alpha from the 12-foot rail launcher at the RRS at the next event. I will relay my findings to the society and back to Additive Aerospace who is very interested to see how their design can work with the RRS micrograin rockets.

[IN CLOSING}

Meeting adjourned at 9:16pm which isn’t too bad. Our hosts at the Ken Nakaoka Community Center continue to graciously allow us to finish up despite the center’s closing at 9:00pm on Fridays. The RRS should seek to better finish on time as the staff at the center need to go home.

The next meeting of the RRS will be held on September 14, 2018.

For questions, contact the RRS treasurer, Chris Lujan.
treasurer@rrs.org

Lawn Atlas Missile Base tour

From the ancient armies of China and India and the 19th century British armies using solid rockets in combat, to Von Braun’s work in Nazi Germany and Robert Goddard’s work with the U.S. Navy during the Second World War, the history of rocketry can not be told without mentioning the military aspects of these powerful devices. Modern rocketry at the dawn of the Space Age has roots in one of the most lethal weapons in mankind’s history.

A few years back (June 2014), my wife and I arranged a tour of an unusual piece of Cold War history in the middle of Texas. Larry Sanders, our gracious host is the owner of a former nuclear missile site just outside of the small town of Lawn, Texas. Through his hard work, he has begun to restore his own Cold War museum at this lonely piece of land adjacent to the rolling Texas plains and pastureland.

Longhorn steer grazes on the Texas prairie next to the Lawn Atlas Missile Base

This area, now called the Lawn Atlas Missile Base (LAMB) was once a first-generation Inter-Continental Ballistic Missile (ICBM) site near the small town of Lawn, Texas, less than 20 miles from Abilene, home to Dyess Air Force Base (AFB). Larry gives tours to schools and other interested parties in the local area of central Texas. He’s also been in the local and regional news for his work in restoring his missile silo into a unique historical site for the public.

Lawn Atlas Missile Base from Google Earth satellite imagery

Larry Sanders article – The Eagle

The Atlas ICBM Highway in central Texas (Texas Highway 604, south of Interstate 20)

Larry Sanders gives a tour of the Lawn Atlas Missile Base site outside of Lawn, Texas

In the early days of the Cold War era, the United States and the Soviet Union were in a race to develop launch vehicles to deliver nuclear warheads to the other side of the world from home and friendly territory. The early ICBM’s were liquid fueled rockets based on the higher performance over solid rocket motors of that time. Liquid oxygen (LOX) and kerosene (RP-1) were common high performance propellants in the late 1950’s and early 1960’s (and still commonly used today). The Atlas rocket stood 82.5 feet tall and 10 feet in diameter and with a gross lift-off weight of 268,000 pounds and a total thrust at sea level of 375,000 pounds from all three of its engines could deliver a W38 nuclear warhead over 9000 miles away.

The basic parts of the Atlas F missile

The Atlas rocket designed and built by Convair in San Diego, California, in the 1950’s. The Atlas used a unique vehicle staging concept called “a stage-and-a-half.” Staging of early rocket vehicles at that time was difficult and often plagued with failures. In the 1950’s, there was a concern about reliably igniting the second stage engines in the thin atmosphere at high altitudes. To counter this, the engineers at Convair devised a vehicle that would use a single set of RP-1 and liquid oxygen (LOX) tanks and rapidly ignite all three engines with pyrotechnic cartridges at the same time on the ground. In the middle of ascent, the booster segment would drop away thereby shedding the weight of the two booster engines with their associated pumps in flight. By doing this, the Atlas would finish the mission with only the middle sustainer engine to the end of the flight as the vehicle became lighter.

Rocketdyne MA-3 engine cluster for the Atlas stage-and-a-half rocket

Rocketdyne of Canoga Park, California, built the complex MA-3 engine system for the Atlas ICBM that had two outboard booster engines and a central sustainer engine. The MA-3 engine had a separate turbopump and gas generator for each of the three engines arranged in a line. The MA-3 engine also had two small vernier engines for roll-control, one on opposite sides over the sustainer.

Rocketdyne MA-3 booster engine, LR89-NA-5; two units

Rocketdyne MA-3 sustainer engine, LR105-NA-5; single core engine

Rocketdyne MA-3 vernier engine used on Atlas F vehicle

Atlas booster with the stage-and-a-half concept; outside booster engines fall away leaving the sustainer engine to finish the flight

The Atlas was the first operational ICBM in the American arsenal during the height of the Cold War. Twelve missile bases such as the one near Lawn, Texas, were clustered in around a central strategic command center, a U.S. Airbase in that region. In this case, Dyess Air Force Base in Abilene, Texas, is the former hub of this set of twelve SM-65 Atlas-F type missile sites.

SM-65 Atlas Missile Sites throughout the United States in the 1960’s

Lawn Atlas Missile Base location with respect to Dyess AFB in Abilene, Texas

The Atlas-F type was the last and most advanced version of the SM-65 series. With the RP-1 kerosene fuel loaded and waiting on standby, the Atlas missile was raised vertically from an underground silo to then be tanked with its cryogenic oxidizer (LOX). Air separation plants and special cryogenic liquid handling equipment were required to fuel these first-generation missiles. During its service life, the US Air Force maintained this land-based system to be ready to launch from the surface of the silo within minutes with just a small highly-trained crew.

Atlas-F, SM-65 ICBM in testing

Today, just a few things remain at the surface including the massive, reinforced concrete silo door slab at the Lawn Atlas Missile Base. Two doors are built into the roof where the missile was lowered and raised from its protective silo in the ground.

Lawn Atlas Missile Base – silo and ground access

Atlas-F missile silo as seen from the surface

Top side panaroma of the LAMB site

The Atlas E and F models were the first American ICBM’s to have an on-board computer for guidance using an inertial navigation system. The missile silo had a fixed sighting station to finely calibrate the missile guidance package to make it ready to accurately strike it’s target on the other side of the world. Some parts of this equipment still remain at the site.

The sighting equipment slab facing to the north of the missile silo seen in the background

Atlas ICBM guidance system using an optical sighting apparatus from within the silo

Remnants of communication equipment left at the site

An old antenna mount at the missile site

In the site’s operational period, there were a few small quonset huts at the surface to park servicing equipment for the missile and the silo. Some of the original foundations from these structures still remain at the site as can be seen in the satellite view.

Sketch of the Atlas missile ground support crew and trailers

Atlas F missile base with quonset hut support buildings

Atlas-F perched on the launch table with the blast deflector in place.

Atlas missile stored within its protective silo, erector structure and lifting equipment can be seen

Atlas silo and its underground control room / missile lifted and ready for launch

Our tour started at the protruding angled structure with the surface door angling down below the ground through a convoluted path to the next door.

Atlas F silo – ground access

Ground level door going into the Launch Command Center (LCC) of the Atlas F missile silo; the emergency escape hatch from the LCC can be seen to the right

Down the stair past the first door at ground level

The path from the ground access door leads down two flights of stairs to a couple of turns leading to a pair of entrapment doors. Beyond the entrapment doors are another pair of vault doors. At the LAMB site, a vintage Coke machine is between the two vault doors. Beyond the vault doors leads to a two-floor stair case giving acccess into the round two-floor Launch Control Center (LCC).

entrapment doors in red; the two vault doors in blue

first turn at the bottom of the stairs

the first of two simple doors just around the first corner

The first of two vault doors leading into the stairwell going into the LCC

Vintage (1960’s) Coke machine just behind the first vault door

Vault door latching mechanism

Mechanical vault door actuator from the inside

Once past the radiation-resistant vault door, the two man crew would descend a two-flight set of stairs to access the two-levels of the round LCC. A vintage Coke machine was just behind the door which was a little bit of civilization inside this rugged castle. The whole missile silo was very cool despite the summer heat at the surface, but the humidity inside of the barren silo was very high. Larry said that he very often had to spread desiccant and was frequently combating the mold that would flourish in the moist darkness.

Stairwell access to the Atlas-F LCC

Plate steel stairwell, entering the top floor of the LCC

Bottom of the stairwell, access to the lower deck of the LCC

The Launch Control Center is a two-floor “pillbox” cylinder bunker that housed the crew and the command equipment for operating the missile and the silo equipment. When the site was decommissioned, nearly all of this equipment was removed leaving only the bare walls and only a few non-military items. Having studied the subject and learning what he could from past missileers, our tour guide Larry provided details of where the crew slept, ate and conducted their duties all underground behind the vault door protected from nuclear attack from above.

Identification of equipment and features inside of the LCC

Nearly all of the original wiring and electrical fixtures were stripped out, so Larry has worked to slowly bring back ambient lighting into the LCC, or at least enough to safely conduct tours. Some of my pictures did not turn out so well in the low light, but the LCC had a lot to see.

Launch Control Center (LCC) of the Atlas-F missile silo

top floor inside the LCC in the Atlas-F missile silo

Crew cots around the circumference of the circular LCC (fuzzy from the low light)

Emergency escape hatch from the LCC

Kitchen area inside the LCC, much of this equipment was added (such as the microwave oven)

American eagle emblem hangs just above the kitchen area in the LCC

The lower level had housed the control equipment. Much of this equipment including the electrical fixtures were stripped away. What remains is an old circular photo darkroom and a really nice poster showing the Atlas SM-65 missile.

Picture of the Atlas SM-65 missile next to the circular darkroom for processing camera film

From within the stairwell at the lower level of the LCC, it’s a two-man job, always

Lower level in the LCC

Another view of the lower level of the LCC

The two-story LCC has an access tunnel leading to the missile silo. This circular path had a flat metal grating floor with a corrugated metal piping wall. This access tunnel was heavily corroded from the years of trapped moisture from the missile silo slowly filling with water as the ground water slowly bleeds through the small pores of the concrete. This is a common problem in subterranean structures, like missile silos. My pictures of this access tunnel were difficult to take from the low light conditions even with the camera flash feature.

Circular access tunnel between the LCC and the Atlas missile silo

LCC access tunnel with silo blast doors

Corrugated metal walls of the access tunnel with empty electrical cable trays

A slightly better view of the access tunnel when looking back at the lighted stairwell

A view back at the access tunnel and silo blast doors from the overhanging deck in the missile silo

The missile equipment and silo structures have been stripped out of the silo during decommissioning leaving a dark cavernous cylindrical vault. Larry had a make-shift metal deck installed just at the edge of the opening to the silo, with a rope ladder leading down to a floating platform he set at the waterline.

A look over the edge of the metal deck just past the access tunnel entrance into the missile silo

overhanging metal deck into the missile silo

view looking down into the empty cavernous missile silo; it’s really hard to appreciate just how huge it is inside

Another view of the missile silo interior wall showing the metallic hard point connections for what might have been the missile elevator equipment to bring the rocket to the surface for launch; only the embedded equipment in the walls remain to rust

The two folding doors remain in the down position as the hydraulic piston actuators to open the doors were moved during decommissioning

Over time, rainwater would leak in from the silo doors at the top. Also, groundwater slowly seeps through the concrete filling the silo roughly half full of very clean, very fresh water. Larry is not entirely sure what, if anything, is remaining down at the bottom of the silo. Divers had once expressed interest in exploring the bottom of the silo, but thus far, no one has explored the bottom. My pictures really do not do justice to this impressive site of being within this empty silent tomb.

Looking up at the silo door in the slab from inside of the missile silo

Floating platform within the empty Atlas-F missile silo full of fresh groundwater

After seeing the missile silo, we returned to the LCC to examine some of the posters and documents Larry had collected on the Atlas missile and the missile base.

Collection of photos and Atlas missile silo information

Location of the Lawn missile base in the set of 12 surrounding Dyess AFB in Abilene, Texas

Figurative drawing of the Atlas F missile silo, on display in the LCC

poster of the Pocket Rockets in Texas

As the Atlas was being deployed as weapon, the rocket fulfilled an important early role in the manned spaceflight program. The first Americans in space, Alan Shepard and Gus Grissom, flew on Redstone rockets, but were unable to reach orbit. John Glenn, the first American to orbit the Earth in 1962, did so in his Friendship 7 Mercury capsule fitted on the more powerful Atlas used as a manned spaceflight vehicle.

An Atlas ICBM adapted to launch the Mercury capsule piloted by John Glenn

John Glenn, the first American to orbit the Earth, catching a ride on an Atlas.

Atlas-Mercury 6 launch

Although the Atlas had a fairly short operational history as an ICBM (1961-1966), derivatives of the same Atlas launch vehicle design continued to serve an important role as a space launch vehicle for military, government and commercial payloads. The remaining Atlas F vehicles became space launch vehicles with the last one flying out in 1981. The Atlas F could loft a 820 kg (1800 lbm) payload to a 185 km polar orbit.

Starting with the Atlas G and H vehicles, the Atlas evolved over the decades all the way into the early 2000’s. The last derivative of the original Atlas ICBM was the Atlas 2AS vehicle with a Rocketdyne MA-5A engine cluster that flew its last flight in 2004.

Atlas H launches a payload to space

An Atlas 2AS takes flight

I really recommend visiting the LAMB site as Larry Sanders has really put a lot of his time and resources into gradually recovering the site from the great state of disrepair after being left dormant for decades. He has done a lot of great work in restoring the place and is active in continuing the project. The LAMB tour offers people a rarely seen part of Cold War history. Although, the missile silo is now an empty vault serving as a museum, it’s easy to forget that this site was built to be one of the most lethal weapon systems ever created. Pictures do not really tell the whole story as visiting the site in person can give you the feeling of being inside a place manned by a handful of dedicated servicemen charged with the awesome and haunting responsibility of maintaining a crucial element of the nation’s nuclear deterrent ready for a day that thankfully never came.

Although the Cold War era ended in 1991, land-based strategic nuclear weapons remain in operation in Russia, the United States, China and other countries around the world.

For future reading, there’s a few websites dedicated to the Atlas missile bases from the Cold War. One has the specific details of the Atlas-F, the last and most advanced in the series.

Atlas Missile Silo

Another good place to look at the old missile sites is SiloWorld.net

Siloworld.net

Also, for those interested in the Atlas SM-65 rocket, Wikipedia has a nice summary.

SM-65 Atlas – Wikipedia

Atlas rocket family – Wikipedia

If you’re ever in the Abilene area and interested in a tour of LAMB or just interested in more information on the LAMB site and Atlas ICBM history, readers are encouraged to contact Larry Sanders by his email below:

atlassilo@yahoo.com

I hope you’ve enjoyed this article as this has been a few years, but a very memorable experience. For any questions or comments, contact the RRS secretary.

secretary@rrs.org

***

MTA launch event, 2018-07-21

The Reaction Research Society (RRS) held a launch event at our private Mojave Test Area (MTA) on Saturday, July 21, 2018. As I came into the site in the morning, I snapped a picture our front gate and the rough location which will be the site of our new sign to arrive very soon.

Follow that car. Turn left to go to the RRS.

Jim Gross was our pyro-op for the event. Many of us arrived early so Jim and the rest of the RRS had time to review the projects we wanted to hot-fire and fly if possible that day. Also, it was new members’, Michael Lunny and Bill Behenna’s first trip to the MTA. I think there is no better way to sell our membership on the benefits of the RRS than your first trip to the MTA. It worked for me!

Jim Gross, our pyro-op for the day

We were glad to host another group of students from the Watts area schools with the support of the Los Angeles Police Department’s (LAPD) Community Safety Partnership (CSP). This has become known as the “Rockets in the Projects” program.

LAPD CSP on Facebook

It was a challenge to hold this event in July in the Mojave desert, but the kids and staff seemed to withstand the 100-degree heat quite well with lots of water and bringing ice. We gave our safety briefing to everyone and explained the do’s and don’t’s for the event. RRS member, Matt Tarditti, was there helping with getting people shuttled around to the places necessary including moving our pyro-op, Jim, and his apprentice, (me) Dave Nordling, back and forth between the bunker and the alpha launch rails. Every step adds up in the heat and it’s wise to work as efficiently as you can. The heat ultimately got to me and I had to take a pause into the air conditioning of my truck. Despite my best efforts in hydration, the Mojave summer was still overwhelming. It is a feeling that many RRS members know all too well at some point in their time with the society at the MTA.

Matt was kind of enough to continue to assist Jim to complete the launch series with the alphas. Even, Jim Gross, who has been a resident of the high desert for many years, was having a tough time in the high temperatures and very low winds of that day. We had extremely low winds which made for great rocket launching weather, however with the building clouds above holding in a lot of the heat of the day, it was a real challenge for everyone to fight the stifling heat. The RRS conducts launch and test events at the MTA year-round, but some months are harder than others.

Matt Tarditti and Jim Gross under the hot July sun at the MTA

The LAPD CSP team does a great job in preparing these kids in the weeks ahead before this event. Often, this is many of the kids’ first trip into the Mojave desert. The stark beauty of the landscape hides the subtle dangers of snakes, spiders and the ever-present risk of heat stroke (even at 10:00 AM!). The RRS educational program is both fun and informative and through preparation everyone can make things safe. The kids were quite ready for the final event in the RRS educational program which is seeing their painted and assembled RRS standard alpha rockets take flight.

Michael Lunny, Frank Miuccio and Larry Hoffing stand among the students during the safety briefing at the George Dosa building

Our first goal of the event was to get the students’ rockets in the air so that those less experienced in the desert heat can go on home once the last one was complete. We had seven standard alphas to be launched, all painted by the students as their way to personalize their team’s flight. As always, the RRS reminds our classes that painting the bodies is nice, but since they return to the ground without a parachute, painting the fins in a bright and observable color matters the most when trying to find them on the desert floor. You’ll only have the tail fins sticking out of the ground when you find your rocket.

Seven alphas in the rack from Watts, plus Larry’s customized alpha with the wires sticking out of the payload tube

The kids paid careful attention to the time of flight which gives some data as to how well packed the alphas were. Two stopwatch measurements were made on each of the seven alpha flights. Impact was not heard on the seventh flight, so no data was taken. The results are somewhat consistent between the two readings and ranged between 36 and 39 seconds.

Time of flight measurements on six of the seven alphas flown on 07-21-2018

Ideal time of flight for an RRS standard alpha is thought to be between 35 and 42 seconds. This would indicate that Osvaldo’s rapid micrograin loading system is doing well to properly pack the propellant leading to good results.

Still shot from Michael Lunny’s video of the RRS standard alpha taking off

After the sequential launch of all seven alphas, it was unanimously decided not to let the kids hunt for their rockets downrange. The LAPD CSP team and the Watts kids went home after taking a picture under our arched sign. RRS member, Michael Lunny, shot a great video of one of the alpha launches from the bunker. I hope to get it posted to the RRS YouTube channel. We have a few micrograin rocket flights on YouTube, but we hope to add more content there soon. You’ll notice our name is not fully spelled out due to the old character limit when the account was made.

ReactionResearchSoc

Reaction Research Society on YouTube

After the Rockets in the Projects, this left the rest of the RRS membership to attempt the other projects we had ready for this launch day.

Richard Garcia brought his home-built rocket that is adapted for the sugar-KNO3 motor he tested at the 2018-06-02 event. He made three motors, one as a simple end-burner, the other two were cored. The plan was to fire conduct a static firing or two with his test motors and if all looked good fly the third motor in the rocket from the RRS rail launcher. “Rocket candy” as it is also called in amateur rocketry has been getting more popular at the RRS.

Richard Garcia stands in the assembly area by his golden rocket built for his custom sugar motor

Richard’s end-burner grain, 2018-07-21

Richard’s nozzle for his custom sugar motor

Richard’s two cored grains, sugar-KNO3 motors, 2018-07-21

Richard brought back his vertical static fire stand that bolts to the larger RRS frame. Although his thrust stand is not outfitted with a load cell (yet), it does give him the opportunity to safely secure his test motors and visually compare the results and time the burns.

Richard Garcia’s sugar motor held down to his vertical thrust stand for static fire

Larry Hoffing made a parachute system in his RRS standard alpha. His system was a little different from Osvaldo’s as he required a second firing line to light a delayed fuse for the parachute deployment system he put in. His son, Max, was there to help get things ready for flight as we included Larry and Osvaldo’s alphas into the launch sequence. Larry’s goal was to explore an older method of timing the deployment of his parachute by use of cannon fuse.

Larry’s alpha payload system being made ready for flight, 2018-07-21

Also, Larry had attached a signalling whistle on one of the fins. The ancient Chinese used to mount whistles on their rockets of war to strike fear in the hearts of their enemies as the rockets would scream to their target. It was Larry’s intent to add the element of sound not only for an impressive screeching launch off the rails, but also for better tracking of the rocket’s final descent to the ground. Although having a single whistle mounted to just one fin will impart a spin to the alpha, the flight will still be stable as proven on similar alpha flights. In the recent past, we have had success flying a larger, single keychain camera on the outside of a single fin while maintaining good flight stability despite the nauseating rapid spin seen in the footage from these externally mounted cameras.

Larry’s alpha with a whistle mechanically fastened to a single fin, 2018-07-21

Osvaldo inspects Larry’s alpha rocket in the launch rails with the second firing line connected for the fused payload timer

Unfortunately, Larry’s alpha had a problem at launch with the failure to light the micrograin rocket. Also, with this delay it was apparent that the parachute payload deployed way too early. The goal was to fire at 20 seconds in the flight and the fuse seemed to go at only 2 seconds popping the payload tube while the rocket stayed on the alpha rack. The two systems had to fire at nearly the same time but one system failed entirely and other went off too early.

After exploring all other failure modes with the firing circuit and procedures, it was confirmed that it was a bad electric match with a break in the wire. This was the first time I’ve seen an electric match fail in the three years I’ve been with the RRS, but it has been known to happen. With Larry’s whole payload system requiring repackaging, it was decided for expediency, just to remove Larry’s rocket from the launch rails, remove the nozzle and dump the micrograin propellant for a safe disposal burn on the ground. Larry will be able to re-use his alpha hardware, but it will have to wait for next launch.

Next was Osvaldo’s red colored alpha with his alpha with a parachute system built in it. Osvaldo made some minor improvements to the circuitry and this was to be his second flight. He also had a commercial telemetry package within his payload section.

Osvaldo’s red alpha with the breakwire switch to start the timer and the pull pin to arm the battery before walking away to the bunker to fire

Osvaldo’s alpha parachute system, break-wire secured to launch rail starts the internal timer

The first flight of his original parachute design for the alpha on 2018-06-02 was a complete success. Despite some slight overheating of the parachute from the black powder deployment charge on the initial flight, the rocket still coasted down very gently such that it laid neatly on the ground and a shovel wasn’t necessary for recovery.

The flight of Osvaldo’s second alpha was similarly successful in that the break-wire system and deployment mechanism operated properly, but the parachute itself failed to unfold due to tangling. The rocket’s descent even with the folded parachute was able to be spotted and Osvaldo recovered all pieces of his second flight.

Osvaldo inspects the second iteration of his alpha parachute system, 2018-07-21

Also, as an added bonus, Osvaldo was able to fit a commercial telemetry package to measure the flight acceleration. As the whole package survived in tact, it will be very interesting what the device was able to measure from within the tight confines of alpha payload tube near the nose. I hope he can present his results from the flight at the next meeting.

Osvaldo’s data package survives the flight, a little singed, and despite a folded parachute

There has been a lot of great progress in parachutes for the RRS standard alpha recently. Both Larry and Osvaldo have made great progress. With the persistent efforts of our RRS membership, I think its reasonable to expect that we could offer a standard alpha parachute package for our future events once we demonstrate a series of successful flights, settle on the design and figure the added cost.

Richard Garcia’s project having two successful static firings gave him confidence to try to mount and fly the third sugar motor. After having some initial integration problems and a rail button coming off, he was able to get his golden rocket ready for a launch on the rail launcher.

The rail launcher at the MTA is a great asset to the society. It has been used on several projects with good success, but it is a very heavy and sturdy device that requires two or three people to assemble and make ready. Also, the pin system that connects the rail to the stand fits very snugly and sometimes requires a lot of elbow grease and persuasion (perhaps with a rubber mallet) to get the right alignment of the holes. Despite the high heat, we managed to get things ready for Richard’s flight.

Rail piece with 12-foot, 80-20, 1515 aluminum rail

Launch rail base

Launch rail system ready to receive the rocket

Underslung launch rail system at the RRS MTA, assembled and ready for Richard’s flight, 2018-07-21

80-20 aluminum 1515 sized rail (1.5-inch) used as the guide for the launcher

Richard checks the manual for the telemetry package that he armed for flight.

Richard’s flight was on one hand a little underwhelming as his sugar motor did not produce a great deal of impulse, but it did manage to propel itself up and get clear of the launch rail before neatly turning back to the ground in a low-speed, but very steady and stable flight. Although his rocket only made it 50 feet downrange, it can be seen in the flight video that his rocket was stable throughout the whole low speed which is a testament to Richard’s good construction of a very aerodynamic and well-balanced vehicle.

The sugar motor doesn’t offer much impulse as it burns out shortly after clearing the launch rail

The rocket gently pitches over after burnout heading for the ground not very far downrange (the last good frame I have from my camera-phone)

After a perfect arc at its low apogee, the rocket turned back to the ground and landed almost perfectly on its nose. Despite the rough landing, the nosecone wasn’t damaged and many parts of the vehicle were similarly undamaged.

A very short, but extremely stable flight off the rails for Richard’s golden rocket with a custom sugar motor

Richard safes his payload system as he inspects the recovered rocket.

Richard will be working on increasing the impulse from his motor, but he can be very confident in his vehicle design. With a little rework on some of the parts, I think he should have a very impressive flight at the next launch event.

Osvaldo has put a lot of work into the horizontal thrust stand that I started. To be able to static fire an alpha rocket to measure the impulse, we have to accomplish two more things.

RRS horizontal thrust stand in need of an extension piece to stabilize an alpha for static fire

The first is to get better mechanical support for an RRS standard alpha to prevent sideways motions or “wagging” during firing. The stout, welded frame of the horizontal thrust stand fits just fine to the concrete slab foundation and is very secure, but the 3-foot length of an alpha could create quite a wicked angular load on the load cell. After Osvaldo and I had discussed a few design concepts, Osvaldo brought his design to the MTA. Given the time constraints of the launch events that came before and the stifling heat, we had no time to attempt a fit check of an alpha rocket in the thrust stand. The complete assembly will have to be fit checked at the next event. Osvaldo had also noticed that when the long alpha rocket is put into this short stand, the rocket doesn’t align very well with the beam. Some minor adjustments might be necessary to make sure the thrust vector is properly aligned with the axis through the load cell.

RRS horizontal thrust stand extension piece

The second thing is to try to calibrate the load cell to make sure the S-type load cell is still reasonably within its original factory calibration. Osvaldo brought in a home-built frame with a hydraulic jack and pressure gauge which can reasonably approximate a force by the pressure and piston area relationship. We didn’t have time to try this setup, but this device can be demonstrated at home if Osvaldo has time before the August 10th meeting.

hydraulic jack testing rig for verifying the S-type load cell calibration

hydraulic jack-based force tester with high pressure gauge attached

The horizontal thrust stand was not ready for the 2018-07-21 launch event due to a lack of cabling and a hardy computer to manage the data acquisition. Many of us are reluctant to bring our personal laptops to run the data acquisition in the abrasive sandy dry lake environment at the MTA. Chris Lujan at the July meeting talked about using a simple Arduino Raspberry Pi computer as a low-cost alternative to gathering and processing the data. Hopefully, the RRS will get a simple device for this purpose and have it programmed to take data from the load cell as we conduct our hot-fires from this horizontal thrust stand. There still is a lot of work to do in getting the horizontal thrust stand working. With more hard work, the RRS will have this project working soon, hopefully by the next launch event in the fall. We’ll post updates as this project advances.

One final note on the event is that the RRS will be posting a few things on Instagram once the secretary (me) has time to get things started. The RRS is brand new to Instagram so we hope to expand our presence here to better show everyone what we do. At first, the RRS executive council will have access to post photos at the events we attend for the RRS. We hope this presence on Instagram will generate more excitement and participation at events with the RRS.

Follow RRS on Instagram

The RRS will certainly discuss today’s launch event as a whole at the next meeting on Friday, August 10, 2018. There were a lot of great things we tried at the event, but there were also a lot of logistical things we can do better next time. Also, it would be a good time to review some of the material improvements that we ought to make at the MTA to better handle the projects we expect in the near future.

Please join us on August 10th!