50 Years After One Small Step for a Man

By Dave Nordling, Secretary, Reaction Research Society


It was a half century ago today that mankind landed on the Moon. This event has had an impact on both generations present to witness this landmark event and the generations born afterward, such as myself. The Apollo 11 moon landing was a daring extension of an aggressive program that was progressively built from the dawn of the space age with abundant resources, acceptance of risk and political will never seen before (and never since). The herculean task set by the late President Kennedy in 1961 of landing a man on the moon and safely returning him to Earth by the end of the decade (1970) was fulfilled on July 24, 1969.

A grainy image of the American flag planted on the moon.

It was only eight years before that time when manned spaceflight began with the humble beginnings of riding a derivative of an intercontinental ballistic missile (ICBM) into low earth orbit scraping the bounds of the upper atmosphere. The journey was fulfilled with the enormous 6,540,000 lbm tower of three stages of the Saturn V vehicle filled with kerosene, liquid hydrogen and liquid oxygen that pushed three brave men into a new sphere of influence of the Earth’s closest celestial body just three days away. New systems and new rocket motors were built from scratch and flown in less than a decade. The massive Saturn V rocket could throw an unprecedented 107,100 lbm to trans-lunar injection (TLI) orbit. No other past or operational launch vehicle has surpassed this ability to this very day.

The Saturn V leaves its pad with a thrust of over 7,500,000 lbf.

Looking back, landing a man on the lunar surface appears simple and almost certain. But to those watching from their black and white televisions across the country and to the men and women behind the launch consoles, all of the Apollo missions were truly audacious with the looming deadline, a Cold War rival busy at work to maintain their leadership in space and an ever-present risk for tragedy at every step. Lives were lost, sacrifices were made and the goal remained steadfast. Excellence was demanded from hundreds of thousands of technical professionals, suppliers, shop workers, clerks and everyday people and was delivered such that two astronauts could walk on a foreign world opening the door to our species visiting a place beyond our blue Earth.

Skipping along the lunar surface getting work done. Beyond the human experience and reflection, this was an expedition filled with experiments to extend human knowledge.

At this 50th anniversary, it is interesting to reflect on what has happened since. After six more Apollo flights with five resulting in 10 more Americans walking, even driving over the lunar surface, the program came to an end under the Nixon Administration’s budget cuts. No other nation, including our own, has returned. It is probably due to this fact alone that more and more people begin to doubt whether the moon landing was ever real.

Also, it is the opinion of this author that because the Soviet Union’s then-secret moon program failed to place a cosmonaut into lunar orbit with their massive N-1 rocket, let alone a successful landing on the lunar surface, that our country saw fit to halt the progress of Apollo and turn our back on the Moon for five decades. I can only imagine how history would be different if the any of the four Soviet launches of the N-1 from February 1969 to November of 1972 had been a success.

The first Soviet N-1 rocket sits on its pad at Baikonaur in September 1968.

https://en.wikipedia.org/wiki/N1_%28rocket%29

The first man on the moon, Neil Armstrong, has passed away just a little less than seven years ago. Buzz Aldrin and Michael Collins remain as living historical witnesses, but in time, they too will pass on. NASA has a huge discontinuity in their chronology of exploration after the Apollo and Skylab program’s success. A long period of quiet then the Shuttle followed by eight years of paying the Russians for rides to the International Space Station (ISS) from Russia is all that remains. Our unmanned program has continued with ever more impressive returns as we learned about the moon, Mars and places throughout in the solar system, but our manned space program remains at a stand-still.

The legacy of Apollo has been more of historical legend and pride than any tangible progress eclipsing this feat of human achievement. The Space Shuttle program and its nearly four decades of life brought us the historical achievement of the first American woman in space, the first African-American in space, the launch of the Hubble Space Telescope, the first visit to a Russian space station, Mir, the first Russian cosmonaut to fly on an American space vessel, and of course the multi-year construction of the ISS celebrating its third decade of operation even after the Shuttle’s retirement. There are many people who feel that the Shuttle program failed its basic promise of routine access to space and certainly to fulfill the loftier goals of men reaching beyond low Earth orbit.

Since the days of Apollo, there have been new discoveries about the Moon. Thanks to the Lunar Reconnaissance Orbiter (LRO) launched in 2009, the Apollo launch sites have been seen in higher detail.

https://www.space.com/14874-apollo-11-landing-site

The Apollo 11 landing site and the crew’s discarded equipment as seen from lunar orbit courtesy of the Lunar Reconnaissance Orbiter.

The Indian ISRO Chandrayaan-1 lunar orbiter, the Japanese Kaguya lunar orbiter and the American LRO have each found evidence of lunar lava tubes and “moon caves” in several places along the lunar surface which offers a tantalizing possibility of a ready-made shelter for future manned exploration.

An excellent new point of interest on the Moon’s surface, lunar lava tubes found by orbiting spacecraft.

https://en.wikipedia.org/wiki/Lunar_lava_tube

Further evidence of ancient lunar lava tubes as seen from orbit.

The discovery of water ice in the permanent shadow in craters at the Moon’s poles starting from the Soviet Luna 24 probe to the ISRO Chandrayaan-1 orbiter provided strong evidence of an important resource awaiting future lunar explorers. .

https://en.wikipedia.org/wiki/Lunar_water

Distribution of water ice at the Moon’s South and North poles

Most recently, on January 3 of this year, the Chinese with the Chang’e 4 have soft-landed a rover (Yutu-2) on the far side of the Moon, a first for any nation.

https://en.wikipedia.org/wiki/Chang%27e_4

Lunar tracks by the Chinese Yutu-2 rover in the soil at the von Karman crater in the South-Pole Aitken Basin region on the far side of the moon.

With the end of the Space Shuttle program in 2011, planned since the Columbia disaster of 2003, the Constellation program, later renamed the Space Launch System (SLS) was built and extended from legacy technologies with years of flight experience.
At this moment in time, NASA has redoubled its commitment to returning people to the surface of the moon in just five years from now, 2024. It is possible this goal can be realized, but there are abundant reasons to be skeptical.

Technology is no longer the perceived barrier to finding our way back to the Moon. The ability of any government or administration to muster the cohesive, sustained political will and necessary funding to build and fly the SLS program to put men back on the moon is the question that remains unanswered. More so, will we have the fortitude to recover from failures should they occur and surmount them to make a permanent colony as was envisioned for after Apollo? To date, my generation has waited in vain on the many promises from NASA to deliver something of the magnitude of Apollo.

There is no shortage of passionate, intelligent people in this world. Many share the vision of mankind becoming an interplanetary species. Our art and culture have been permanently changed from seeing the whole of our world as a small blue marble against the enormous blackness of space. The true legacy of Apollo is the inspiration that was given to this nation’s people and any nation seeking to find pride in their abilities to put their citizens in space. Regardless of what may come in the next few years with NASA, the dream is alive with the people of the Earth to be explorers. To move beyond dreams is what will extend mankind to the Moon and beyond.


Liquid Rocket Components: Pyrotechnic Valves

by Tom Mueller


Editor’s Note: This is a reprinting of the original article written by RRS member, Tom Mueller on the subject of pyrotechnic actuated valves around 1995 (?). He mentions the build of two different rockets (the XLR-50 and the Condor) and a hypergolic rocket he intended to build after this article was written. We hope to gather more photos and details about these rockets and display them in future improvements to this posting. For now, please enjoy the subject matter as the information is very relevant today to amateur builders of liquid rockets. The RRS has been very active lately in re-exploring liquid rockets. The society thought this would be a timely and interesting subject to share with our readers.

For any questions, please contact the RRS secretary, secretary@rrs.org


For an amateur rocketeer seeking to build a liquid rocket, one of the most difficult components to obtain or build are remotely operated valves. A liquid rocket will require at least one valve to start the flow of propellants to the combustion chamber. In the two small liquid rockets I have flown in the last year or so, both used a pyrotechnic fire valve located between the pressurant tank and the propellant tanks. The propellants were held in the tanks by burst disks (or equivalent) in the propellant run lines. When the fire valve was actuated, the sudden pressure rise in the propellant tanks blew the burst disks, allowing propellant to flow to the injector. This method of controlling the flow to the rocket allows the use of only one valve, and eliminates liquid valves.

In the case of the first rocket, the XLR-50 which flew in October 1993, elimination of the liquid valve was important because the oxidizer was liquid oxygen, and a small cryogenic compatible valve is very difficult to construct.

For the second rocket, which flew in October 1994, the small size prevented the use of liquid valves. In fact, the single pyro valve I used was barely able to fit in the 1.5 inch rocket diameter. In this article I will describe the design of the valves that were used on these two vehicles, and variations of them that have been used in other rocket applications.

FIGURE 1: XLR-50 pyro-technic “fire” valve

The valve shown in Figure 1 consisted of a stainless steel body with a 0.375 inch diameter piston. The O-rings were Viton (material) and the squib charge was contained in a Delrin plastic cap. The Delrin was used to prevent shorting of the nichrome wire, and also to provide a frangible fuse in case the squib charge proved to be a little too energetic. In practice, I’ve never had the Delrin cap fracture.

The inlet and outlet lines to the tanks were silver brazed to the valve body. The valve was tested many times at inlet pressures of up to 1000 psi without any problems, other than the O-rings would need replaced after several firings due to minor nicks from the ports. To help alleviate this problem, the edges of the ports were rounded to help prevent the O-ring from getting pinched as the piston translates. This was accomplished using a small strip of emery cloth that was secured in a loop in one end of a short length of 0.020-inch stainless steel wire. The other end of the wire was clamped in a pin vise which in turn was chucked in a hand drill. As the wire was rotated by the drill, the emery was pulled snugly into the port, where it deformed into the shape of the inlet, and rounded the sharp edge. I used WD-40 as a lubricant for this operation, allowing the emery to wear out until it would finally pull through the port. I repeated this process a few times for each port until the piston would slide through the bore without the O-rings snagging the ports.

Another requirement is to lubricate the O-rings with a little Krytox grease. This helps the piston move freely and greatly reduces the problem of nicked O-rings.

FIGURE 2: Fire valve for a micro-rocket

The pyro valve I used in the 25 lbf thrust micro-rocket that was launched in October of 1994 is shown in Figure 2. This valve was identical in operation to the XLR-50 valve, with the major difference being its integration into the vehicle body. The valve body was a 1.5 inch diameter aluminum bulkhead that separated the nitrogen pressurant tank and the oxidizer tank. Because of the very small diameter of the rocket, the clearances between ports and O-rings were minimized, just allowing the valve to fit. The fuel outlet port was located at the vehicle center, providing pressure to the fuel tank by the central stand pipe that passed axially down the oxidizer tank. The piston stop was a piece of heat-treated alloy steel that was attached to the valve body by a screw. This stop was originally made from aluminum, but was bent by the impact of the piston in initial tests of the valve. The black powder charge in the Delrin cap was reduced and the black powder was changed from FFFg grade to a courser FFg powder, but the problem persisted. The stop was re-made from oil hardening steel and the problem was solved. In this application, the port diameters were only 1/16 inch so only a small amount of rounding was required to prevent the O-rings from getting pinched in the ports. The valve operated with a nitrogen lock-up pressure of 1000 psi.

FIGURE 3: Fire valve for Mark Ventura’s peroxide rocket

A more challenging application of the same basic valve design was used for the fire valve of Mark Ventura’s peroxide hybrid, as shown in Figure 3. This was the first application of this valve where liquid was the fluid being controlled, rather than gas. In this case the liquid was 85% hydrogen peroxide. The second difficulty was the fact that the ports were required to be 0.20 inch in diameter in order to handle the required flow rate. The valve was somewhat simpler than the previous valves in that only a single inlet and outlet were required. The valve body was made from a piece of 1.5-inch diameter 6061 aluminum, in which a 1/2-inch piston bore was drilled. The piston was also 6061 with Viton O-rings, which are peroxide compatible. The ports were 1/4-inch NPT pipe threads tapped into the aluminum body. The excess material on the sides of the valve was milled off, so that the valve was only about 3/4 of an inch thick, and weighed only 4 ounces. Even though the piston size was 1/2 inch, the same charge volume used in the 3/8 inch valves was sufficient to actuate the piston.

In testing the valve with water at a lock-up pressure of 800 psi, I was pleased to find that even with the large ports, O-ring pinching was not a problem. One saving factor was that the larger size of the ports made it easier to round the entrances on the bore side. The valve was tested with water several times successfully before giving it to Mark for the static test of his hybrid.

The only problem that occurred during the static test of hybrid rocket was that the leads to the nichrome wire kept shorting against the valve body. Three attempts were made before the squib was finally ignited and the engine ran beautifully. I have since been able to solve this problem by soldering insulated 32-gauge copper wire to the nichrome wire leads inside the Delrin cap. In this way, I can provide long leads to the valve with reliable ignition.

My next liquid rocket is a 650 lbf design that burns LOX and propane at 500 psia. This engine uses a Condor ablative chamber obtained from a surplus yard. For this reason, I call it the Condor rocket. This rocket uses a scuba tank with 3000 psi helium for the pressurant. I decided to build a high pressure version of my valve as the helium isolation valve for this rocket. When firing this rocket, just prior to the 10 second count, this valve will be fired, pressurizing the propellant tanks to 600 psi. I assumed going in to this design that the O-rings slipping past a port simply wasn’t going to work at 3000 psi.

At these pressures, the O-ring would extrude into the port. In order to get around this problem I came up with the design shown in Figure 4.

FIGURE 4: High pressure helium valve for Condor rocket

For this valve, the O-ring groves were moved from the piston to the cylinder bore of the valve body, so the O-rings do not move relative to the ports. The piston is made from stainless steel with a smooth surface finish and generous radii on all of the corners. The clearance between the piston and the bore was kept very small to prevent extrusion of the O-rings. The valve operation is similar to the one shown in Figure 3, and the valve body is made in the same way except female AN ports were used rather than NPT ports. When the valve is fired, the piston travels from the position shown in Figure 4a to that shown in Figure 4b. During this travel, the inlet pressure on the second O-ring will cause it to “blow out” as the piston major diameter translates past the O-ring groove. The O-ring is retained around the piston, causing no obstruction or other problems. This valve has been tested at 2400 psi inlet pressure with helium and works fine. It will be tested at 3000 psi prior to the first hot fire tests of the Condor rocket next spring.

As a side note, essentially an identical valve design as the one used on the Condor and Mark’s valve is a design shown in NASA publication SP-8080, “Liquid Rocket Pressure Regulators, Relief Valves, Check Valves, Burst Disks and Explosive Valves”.

A second pyro valve is used on the Condor system as shown in Figure 5. This valve is used to vent the LOX tank in the event of a failure to open the fire valve to the engine.

FIGURE 5: Emergency vent valve for LOX tank, Condor rocket

When the propellant tanks are pressurized by the helium pyro valve, the LOX tank auto vent valve (shown in Figure 6) closes. If the engine is not fired after a reasonable amount of time, the LOX will warm up, building pressure until something gives (probably the LOX tank). The pyro valve shown in Figure 5 is used as the emergency tank vent if the engine cannot be fired. The valve body is stainless steel with a stainless tube stub welded on for connection to the LOX tank. This valve has been tested to 800 psi with helium and works fine. In this case, some ‘nicking’ of the O-rings can be tolerated because the O-rings are not required to seal after the valve is fired. The ports in the bore are still rounded, however, to prevent the O-rings from getting nicked or pinched during assembly of the valve.

Even though it is not a pyro valve, I have shown the LOX auto-vent valve in Figure 6 because this design has proven to be very useful for venting cryogenic propellant tanks without requiring a separately actuated valve or control circuit. The valve uses a Teflon slider that is kept in the vent position as shown in Figure 6a.

This allows the tank to vent to the atmosphere, keeping the propellant at its normal boiling point. When the helium system is activated, the pressurant pushes the slider closed against the vent port, sealing off the LOX tank, as shown in Figure 6b. An O-ring is used around the slider to give it a friction fit so the aspiration of the LOX tank does not “suck” the slider to the closed position. This problem happened to David Crisalli (fellow RRS member) when he scaled this design up for use on his 1000 lbf rocket system. I have used this design on the LOX tank of my XLR-50 rocket, which used a 1/4-inch diameter slider, and on the Condor LOX tank, which uses a 1/2 inch slider. In both cases the vent valve worked perfectly.

FIGURE 6: Automatic LOX tank vent valve

The main fire valve on the Condor rocket is a pair of ball valves that are chained together to a single lever so that both the fuel and oxidizer can be actuated simultaneously for smooth engine startup. For static testing of the rocket, I will use a double-acting air cylinder to actuate the valves. For flight, however, I plan to use a pin that is removed by an explosive squib to hold the valve in the closed position. When the squib is ignited, the pin is pulled by the action of the charge on a piston, allowing the valves to be pulled to the open position by a spring. This method may not be very elegant, but it is simple, light, and packages well on the vehicle. David Crisalli has successfully employed this technique on his large rocket.

That covers the extent of the pyro valves I have built or plan to build so far. In the next newsletter, I will present the design and flight of the small hypergolic propellant rocket that used the valve shown in Figure 2.


75th anniversary symposium was a success!

The Reaction Research Society (RRS.ORG) was happy to celebrate its 75th anniversary as the country’s oldest continuously operating amateur rocketry society on April 21, 2018. At the Ken Nakaoka Community Center in Gardena, California, we shared this special occasion with over 300 people from the Los Angeles and San Diego area and welcomed several guests from places further away.

(left to right) Osvaldo Tarditti, Bill Janczewski, Dave Nordling, Jim Gross, Frank Miuccio, Larry Hoffing, Alastair Martin, Richard Garcia, Bill Claybaugh, Drew Cortopassi, Chris Lujan

RRS member, Michael Lunny mans the front desk at the 2018 RRS symposium

RRS members, Jim Gross and John Mariano at the 2018 symposium

Osvaldo Tarditti, George James, George Dosa and Jerry Irvine at the RRS symposium

Bill Claybaugh and RRS founder, George James, at the 2018 RRS symposium

The RRS had a display of some of our society projects past and present. Also, some of our members had their projects on display including Richard Garcia’s liquid rocket and Bill Claybaugh’s massive two-stage rocket.

Richard Garcia discusses his liquid rocket vehicle at the 2018 symposium

An early liquid rocket test motor from George Dosa, furfuryl alcohol and nitric acid

RRS micrograin rockets on display with historical notes

Bill Claybaugh, Osvaldo Tarditti and Bill Janczewski stand before Claybaugh’s two-stage solid rocket on display

Photo montage of micrograin rocket launches

All thirteen RRS mail flights from 1947 – 1990

We had copies of the special 75th anniversary edition of the RRS Astrojet newsletter available for sale at the symposium. Thank you to Bill Janczewski for his hard work in making this high quality newsletter and the bright sign on the column for everyone to see as they came in. The Astrojet can still be purchased through our RRS.ORG website at our PayPal button if you write a note for “Astrojet, (X) copies” and send your mailing address.

Or just simply contact the RRS by email.
secretary@rrs.org

75th anniversary issue of the Astrojet newsletter on sale

We shared our exhibition space with the Los Angeles Air Force Base’s (LA AFB) Space and Missile Command (SMC) as they presented the long history of SMC. Our thanks to Lt. Col. Porter and his team for having a huge display of the Air Force’s contributions to space, national security and improvements to our daily lives. Also, the air-driven rocket launcher demonstration in the courtyard was a big hit.

Karen Austin, Director of SMC History at the 2018 RRS symposium

LA AFB SMC history on display at the 2018 RRS symposium

Lt. Col. Porter speaks at the SMC history exhibit

Also, just outside the Ken Nakaoka Community Center in Gardena, was our colleagues at the Los Angeles Police Department (LAPD) Community Safety Partnership (CSP). Officers who have supported and participated in the rocket build classes we’ve had with Watts and Compton area schools were on hand to answer questions and show off the fun we’ve had over this last year.

LAPD CSP at the 2018 RRS symposium

We had several universities exhibiting and presenting at the RRS symposium including University of California Los Angeles (UCLA), University of Southern California (USC) and California State University Long Beach (CSULB). All of them had impressive work to show with flights pending in just a few weeks before the semester or quarter ends.

CSU Long Beach exhibits and presents at the 2018 RRS symposium

The Additive Rocket Corporation of San Diego exhibited and presented their unique technology.

The Additive Rocket Corporation of San Diego exhibits and presents at the RRS symposium

Other exhibitors at the RRS symposium was our fellow amateur rocketry group, Rocketry Organization of California (ROC).
Rocketry Organization of California

ROC on display at the 2018 RRS symposium

The Notre Dame Academy was also present at our symposium.
Notre Dame Academy – WIkipedia

Notre Dame Academy at the 2018 RRS symposium

Our friends at the China Lake Museum also had a display to show the Navy’s contributions to rocketry and the national defense.
China Lake Museum

China Lake Museum on display at 2018 RRS symposium

U.S. Rockets was also exhibiting at the RRS symposium.
U.S. Rockets – Jerry Irvine

U.S. Rockets exhibiting at the RRS symposium

We had several speakers presenting on current and historical topics of professional and amateur rocketry including Jacky Calvignac of Northrop Grumman, our founder George James of his organization, The Rocket Research Institute (RRI), John Steinmeyer of Orbital-ATK and David Krause of NASA Goddard Spaceflight Center’s Wallops Island Flight Facility in Virginia who called in by Skype.

George James, founder of the RRS, presents on behalf of the RRI

Jacky Calvignac shows the propulsion programs at Northrop Grumman

High School Rocket Propulsion Lab and new RRS members present their test firings from the RRS MTA

Aerospace Corporation’s presentation on additive manufactured propellant grains

We thank all of our attendees, presenters, exhibitors and just everyone who stopped in and had a good time with us. The RRS would like to especially thank Tony Richards for his photography taken at the RRS symposium.

The RRS will discuss at our next monthly meeting on May 11th if we’ll have another symposium next year in 2019. Based on the overwhelming response, this is very likely.