Saturday, March 31, 2012

Conservative distrust of science



It is interesting to see that the general public had a pretty good, ca .5, relationship with science around the time Apollo ended. I bet if you went back to the 50's and 60's, the numbers would be even better. When you stop exploring in a way that is visible to the public, they will no longer grow up loving science.

"An analysis of 36 years' worth of polling data indicates that confidence in science as an institution has steadily declined among Americans who consider themselves conservatives, while confidence levels have been at steadier levels for other ideological groups.

The study, published in the April issue of the American Sociological Review, provides fresh ammunition for those who complain that conservative views on issues such as climate change are at odds with the scientific consensus."

MSNBC

It is clear that, as a republican candidate, you simply cannot run for president without denying some form of established science. Just ask Sarah the 'cuda Palin who ridiculed important research (shrimp on a treadmill or fruit-flies iirc) or worse, McCain who called a world-class planetarium "an overhead projector."

McCain's planetarium problem

One would be hard-pressed to find a more dangerous thing than embracing ignorance as a virtue. It happened in the middle east about 800 years ago. Baghdad was once the center of learning and knowledge, and the largest city in the world, but that all changed with the increase of a sect of Islam that did not accept science and math. That is, after revolutionizing math, astronomy, optics, etc., the golden age of Islam died quite abruptly. The crusades and mongols did not help either... And centuries later, the middle east has yet to recover completely! Let us not make the same mistake.

Space furnace for micro-gravity experiments


"A space furnace like this heats samples of the intermetallics while they are on board the rocket. At around 1600 °C titanium aluminide melts. As the molten sample cools, it turns solid again. Deeper understanding of how titanium aluminide behaves during this process will lead to improved techniques for casting it in moulds.

Made by: European Space Agency (ESA)"

Currently on display in: Challenge of Materials
Year made : 2002
Inventory number : L2008-4005

Friday, March 30, 2012

Project Sabot-Cam: Punkin Chunkin Camera Payload






"Project: the "SABOT-CAM"

Client: Discovery Channel, "Punkin Chunkin World Championship"

Objective: Capture the perspective of a pumpkin, in HD-Video, as if you were shot from the worlds biggest pumpkin cannon. No CG, but real footage from a camera carrying projectile. The projectile must travel the same distance as a competition pumpkin(4500' downrange), and capture both front and rear views, from muzzle to ground."

I wanted to keep the post rate to a steady and predictable 1 per day... but there is just too much cool stuff going on these days!

More about Sabot-Cam on TRF

*Update new thread:

See the flight info here.


A nuclear test and a blimp

Super Loki Dart booster on sale - $600




"It represents a significant part of the 60's Space program and is a definite piece of history as the government fired a limited number of these rockets up 40-50 miles doing high altitude meteorological research. Everything that this rocket accomplished was a result of the first 2.2 seconds (the motor burn). Seperation would occur at around 10,000 ft, at that point it would be doing 4600 - 4800 MPH. The top dart would coast from the seperation altitude to apogee (250,000 ft - 50 miles)....to me, that's simply amazing!

It is made from aluminum, measures 79" long, 4" in diameter not counting the four 8"x2" fins. It weighs 12-1/2 lbs (no payload). It is also painted a faded military greenish color and features cool looking burn marks from being launched. It originally featured a 52" top dart which I never acquired so I turned a smaller tip for it from wood on a lathe then painted red just so it would display nice."

I think I would rather have the dart, but this is still very cool! Note that this 80 inch x 4 inch case, much longer than a CTI Pro-x 98mm 6GXL, only weighs about as much as the CTI case... and that is with fins! Good mass fractions are crucial to high performance flight. The rocket approximates my ideal hobby rocket stage; a N5800 motor with aluminum fins welded onto the case, and a short aluminum nosecone attached directly to the top of the motor case. This rocket could achieve about 80,000 feet if launched from sea level. More importantly, as an upper stage ignited in the regime between 30,000 and 50,000 feet, this type of rocket could be expected to break 100 km.

Listed on Craigslist.

First posted at TRF.

Thursday, March 29, 2012

Mark-1 space chamber

Click to see the full res.

"Capt. Catercia Isaac checks out the inside of the Mark-1 space chamber Oct. 5, 2009, at Arnold Air Force Base, Tenn. Capt. Issac is a physicist and the flight commander of the 718th Test Squadron. The Mark 1 Test Facility is a state-of-the-art space environment simulation test chamber for full-scale space systems testing." - U.S. Air Force photo/Lance Cheung

USA Wind Map



"An invisible, ancient source of energy surrounds us—energy that powered the first explorations of the world, and that may be a key to the future.

This map shows you the delicate tracery of wind flowing over the US right now."

http://hint.fm/wind/

Wednesday, March 28, 2012

Able and Baker fly into space



On May 28, 1959, aboard the JUPITER AM-18, Able, a rhesus monkey, and Miss Baker, a squirrel monkey, became the first monkeys to successfully return to Earth after traveling in space.

Able was born at the Ralph Mitchell Zoo in Independence, Kansas.

They travelled in excess of 16,000 km/h, and withstood 38 g (373 m/s²).

Able died June 1, 1959 while undergoing surgery to remove an infected medical electrode, from a reaction to the anesthesia.

Baker died November 29, 1984 at the age of 27 and is buried on the grounds of the United States Space & Rocket Center in Huntsville, Alabama.

Able was preserved, and is now on display at the Smithsonian Institution's National Air and Space Museum.

Their names were taken from a phonetic alphabet.

...Miss Baker wore a tiny helmet lined with rubber and chamois leather plus a tiny jacket for launch, in addition to a respiration meter affixed to her nose with model cement, and she was fitted into a snug capsule of shoebox size, 9¾ x 12½ x 6¾ inches (24.8 x 31.8 x 17.1 cm) insulated with rubber and fiberglass. Life support was an oxygen bottle with a pressure valve, and lithium hydroxide to absorb moisture.

On May 28, 1959, at 2:39 A.M., a Jupiter rocket lofted Miss Baker and Miss Able to an altitude of 300 miles (480 km) through an acceleration of 38 gs for a 16-minute flight which also included 9 minutes of weightlessness. The flight traveled 1,500 miles (2,400 km) downrange from the pad at Cape Canaveral launch complex 26B to the Atlantic Ocean near Puerto Rico where the capsule was recovered by USS Kiowa...

Monday, March 26, 2012

Underwater Missile Launch



I understand this is a Russian naval launch, but what kind of rocket exactly? Is it launched out of water because the ship cannot handle the blast?

Aeronaut 2011 Supersonic Launches

Sunday, March 25, 2012

Nuclear power requires lots of metal

Two nuclear weapon physics packages.


Two extremely thick (ca. 3 feet) steel parts for a nuclear reactor pressure vessel.

Saturday, March 24, 2012

Avco nosecone test

Worlds largest computer




"The AN/FSQ-7 is physically the largest computer ever built, and will likely hold that record for the future. Each machine used 55,000 vacuum tubes, about ½ acre (2,000 m²) of floor space, weighed 275 tons and used up to three megawatts of power.

The Semi-Automatic Ground Environment (SAGE) was an automated control system for tracking and intercepting enemy bomber aircraft used by NORAD from the late 1950s into the 1980s. In later versions, the system could automatically direct aircraft to an interception by sending instructions directly to the aircraft's autopilot.

By the time SAGE was completely operational, the Soviet bomber threat had been replaced by the Soviet missile threat, for which SAGE was entirely inadequate. Nevertheless, SAGE was extremely important; it led to great advances in online systems and interactive computing, real-time computing, and data communications using modems. It is generally considered to be one of the most advanced and successful large computer systems ever developed.

Both MIT and IBM supported the project as contractors. IBM's role in SAGE (the design and manufacture of the AN/FSQ-7 computer, a vacuum tube computer with ferrite core memory based on the never-built Whirlwind II) was an important factor leading to IBM's domination of the computer industry, accounting for more than a half billion dollars in revenue, nearly 10% of IBM's income in the late 1950s.

Prior to the introduction of SAGE, the task of intercepting bombers was becoming increasingly difficult. This was the latest shift in a balance of power that had been see-sawing since the 1930s...
The problem became even more acute if the bombers attacked at low level. Radar is line-of-sight, so by approaching close to the ground they would remain hidden behind the curvature of the Earth until approaching to within a few tens of miles...

It was this problem that particularly bothered Dr. George E. Valley, an MIT physics professor. In order to provide any sort of protection for the entire USA, a series of radar stations would have to span both coasts and across Canada. In the event of a raid, there would simply be far too many reports to be able to successfully guide interception. His solution was automation, connecting all of the radar sites to a computer which would then control all of the incoming and outgoing flow of information...

Production of the resulting machines, known technically as the AN/FSQ-7, was awarded initially to RCA but later given to IBM, who started production in 1958...

The AN/FSQ-7 is physically the largest computer ever built, and will likely hold that record for the future. Each machine used 55,000 vacuum tubes, about ½ acre (2,000 m²) of floor space, weighed 275 tons and used up to three megawatts of power. Although the machines used a large number of vacuum tubes, the failure rate of an individual tube was low due to efforts in quality control and a novel quality assurance system called marginal checking that discovered tubes that were growing weak, before they failed. Each SAGE site included two computers for redundancy, with one processor on "hot standby" at all times. In spite of the poor reliability of the tubes, this dual-processor design made for remarkably high overall system uptime. 99% availability was not unusual.

SAGE sites were connected to multiple radar stations which transmitted tracking data (range and azimuth) in digitized format by modem over ordinary telephone lines. These digitized inputs were automatically prepared from analog radar inputs by the AN/FST-2B (or successor, AN/FYQ-47[4]) at the radar stations. The SAGE computers then collected the tracking data for display on a CRT as icons. Situation Display (SD) console operators at the center could select any of the "targets" on the display with a light gun, and then display additional information about the tracking data reported by the radar stations. Each SD operator console was equipped with an integral cigarette lighter and ashtray...

The total engineering effort for SAGE was immense. Total project cost remains unknown, but estimates place it between 8 and 12 billion 1964 dollars (60--90 billion 2011 dollars), more than the Manhattan Project that developed the nuclear bomb that SAGE defended against..."


Affordable personal computers are now available for most of the world's population.

Friday, March 23, 2012

AKS Rockets



http://www.aksrockets.blogspot.com/ is a great source for build reviews as well as lots of general rocketry information.

Thursday, March 22, 2012

Project Daedalus in Xenology










"If technically advanced alien civilizations can build starprobes and send them to Sol, how long will it be before humanity can construct and launch interstellar messenger vehicles of its own? A small group of engineers and physicists, all members of the British Interplanetary Society (BIS), decided to find out. In February 1973 they initiated Project Daedalus, an impressive four-year feasibility study of a simple interstellar probe mission using only present-day technology or reasonable extrapolations to near-future capabilities. More than 10,000 man-hours were expended directly on the Project, which culminated in April 1977 with a prototype design and finally in 1978 with the publication of the final report. The following is a very brief summary of the design and mission specifications for Project Daedalus (Figure 24.14), the first comprehensive starship design study in the history of mankind.

The basic mission profile involves an unmanned and undecelerated starprobe which executes a flyby of Barnard’s Star at a distance of about 6 light-years from Earth. This particular target was chosen, not because of its inherent superiority to a Centauri (a closer and more likely system to harbor life3224), but rather because it lies near the midpoint of the expected maximum useful range of the Daedalus vehicle -- roughly 10 light-years.

The final design calls for a starship with a total initial mass of 54,000 tons, of which 50,000 tons is propellant in the form of deuterium/helium-3 frozen fuel pellets. The vehicle consists of a two-stage nuclear pulse rocket, a widely discussed conventional interstellar propulsion technique that has been described extensively in the literature. (See Chapter 17.) The trip to Barnard’s Star would require about 20 years of R&D effort (design, manufacture, and vehicle checkout), 50 more years of flight time at about 12%c, followed by another decade of data transmission from the probe relating to approach, encounter, and exit science. Therefore a basic funding commitment over at least the next 80 years would be required for implementation and successful completion of the mission.

As shown in the time-into-mission graph in Figure 24.14, the Daedalus starprobe would leave the Solar System probably from near-Jovian space. This is because the helium-3 needed for fuel is rare on Earth and must be harvested from the atmosphere of Jupiter using "aerostat factories" floating in the jovian air at medium altitudes. (This technology obviously requires at least a mature spacefaring Type I cultural level among humans, which should be attainable in the next century here on Earth.) The boost period, involving three propellant tank drops and a single stage separation, would last 3.8 years. At the end of these events, the starprobe would have achieved a cruising velocity of about 12%c."


If you have been reading Xenology, check out 24.3.4 for info about Project Daedalus.

Wednesday, March 21, 2012

Sealab - Experimental underwater habitats








"SEALAB I, II, and III were experimental underwater habitats developed by the United States Navy to prove the viability of saturation diving and humans living in isolation for extended periods of time. The knowledge gained from the SEALAB expeditions helped advance the science of deep sea diving and rescue, and contributed to the understanding of the psychological and physiological strains humans can endure."

Tuesday, March 20, 2012

Xenology



Xenology.info

"Xenology: An Introduction to the Scientific Study of Extraterrestrial Life, Intelligence, and Civilization (First Edition, Xenology Research Institute, 1975-1979, 2008). Topics include the history of the idea of extraterrestrial life; comparative planetology, stars, and galaxies; xenobiology (definition/origin of life, exotic biochemistries, and possible alien bioenergetics, biomechanics, sensations, reproduction, and intelligence); extraterrestrial civilizations (energy sources, biotechnology, interstellar travel, alien weapons, planetary and stellar engineering, xenosociology, and extraterrestrial governments and culture); interstellar communication techniques; and the sociology, legal issues, and appropriate interaction protocols pertaining to first contact."

Monday, March 19, 2012

Corona - CIA photo-reconnaissance satellite



"This film concerns the Corona program that produced the world's first photo-reconnaissance (spy) satellites. The film was produced by the Central Intelligence Agency (CIA) and premiered at the "Piercing the Curtain" conference in May of 1995. The film provides an in-depth examination about how and why the Corona program was created, as well as a detailed technological account of how the satellite was built, and its specific operations and capabilities. The film includes footage of Richard Helms, who was the director of the CIA from 1966-1973, as he addressed a press conference about the Corona mission."

This is part 1 of 4, click through video to see the rest.

Sunday, March 18, 2012

VERA: A low cost, low acceleration transonic impact gun



First seen on The Original Rocket Dungeon.

"In the world of ordnance system development the need for system and subsystem testing under dynamic conditions is obvious. A number of approaches have been used by various agencies throughout the years. Rocket sleds. Powder guns. Compressed gas guns. Although each approach has its advantages and disadvantages, it is the disadvantages of traditional approaches that led to the creation of the Variable Energy Research Accelerator (VERA). Rocket sleds are often too expensive for small programs to utilize for extensive test series, and in addition to challenging packaging issues, traditional guns present a violent acceleration profile that can damage test hardware. The designer of VERA endeavored to create a cost effective system to deliver useful payloads to useful velocities while subjecting payloads to acceleration forces significantly lower than those associated with typical gun systems. The result of this effort is VERA.

VERA is a low cost, low acceleration, compressed charge combustion gun featuring a 40 foot (12.2 m) barrel and a 19 inch (483 mm) bore. VERA was designed to minimize payload acceleration forces, accommodate large and/or oddly shaped projectiles, and allow for in-barrel instrumentation and control of energetic or inert payloads.

And yes, VERA, can best be described as a 'potato gun on steroids.'"

I bet everyone is thinking the same thing... at some point they have to rotate this thing to 85 degrees and see how high the payloads can go. Or better still, use it to kick-start a rocket.

Orion nuclear pulse rockets from 10 meters to 200 Mt




The smallest orion, a 10 meter NASA prototype, would have been useful for manned missions to the planets. Initially it would be great for a Mars return trip, carrying tons of payload and arriving quickly. A modified or slightly larger orion would have been suitable for return trips to and from the Jovian Planets. Larger rockets still could carry permanent bases, or astronauts in style. The largest orion craft would be able to fly small cities. These would be ideal generation ships, slowly traveling to other star systems. Only the largest orion spacecraft could make a practical, single generation trip to a local star. These would have to be extremely large, the size of a real city, and be of the "thermal" type where forward thrust is generated by the absorption and re-radiation of photons from large radiation implosion type bombs.

Saturday, March 17, 2012

Interested in making your own rocket motors?


Experimental rocketry, EX for short, has been around longer than hobby rocketry. Experimental rockets were among the first modern rockets to be built, including the first bi-propellant rocket built and flown by Robert Goddard about 86 years ago. One must be very careful to learn before building, as rocket propellants are flammible, and rocket motors frequently explode when they fail. In addition, it is essential to obey all laws and safety recommendations from the experts. But many Americans, and people all over the world, build their own rocket motors rather than buy them from a vendor. These people build their own motors and discuss motor building, internationally. They do so legally. Information about rocketry and propellants is public domain knowledge. Discussion of this information is protected by the bill of rights. Public libraries, websites, universities, they all contain information about rockets and how to build them. Obviously one should survey the field, and consider purchasing a book on the topic, long before actually building a rocket motor. One should talk to, and work with other EX builders. Many NAR/Tripoli launches have EX flights, or have flyers who are part-time in EX. Talking to them will be your most valuable source of information. Here is some preliminary reading:

Friday, March 16, 2012

Can paint save a house from the thermal radiation of a nuclear bomb?



"National Paint, Varnish and Lacquer Association Atomic tests at the Nevada Proving Grounds (later the Nevada Test Site) show effects on well-kept homes, homes filled with trash and combustibles, and homes painted with reflective white paint. Asserts that cleanliness is an essential part of civil defense preparedness and that it increased survivability. Selected for the 2002 National Film Registry of "artistically, culturally, and socially significant" films."

Thursday, March 15, 2012

Brand new kit - Formula 98


The Rocketry Warehouse has just announced a new kit, called the Formula 98. This is the big brother to the Formula 75 that I have just finished. This kit is going to be on sale, at least initially, for an incredible $100!

Kit Pictured in Tangerine.

Specs:
1. Over 62 Inches Tall
2. Built Weight 8 Lbs
3. CNC Precision Cut Parts
4. CNC Precision Slotted
5. Flies on everything from I to K
6. Perfect for Level 1 and Level 2
7. Requires NO Paint

Parts:
A. Black Fiberglass Filament Wound Nosecone & Coupler 22.5" Exposed Length
B. Black G10 Fiberglass Nosecone Bulkplate
C. G12 Fiberglass 4" Fiberglass Upper Tube 16” Length
D. G12 Fiberglass 4" Fiberglass Booster Tube 24” Length
E. G12 Fiberglass 54mm Motor Tube 12” Length
F. Black G10 Fiberglass 1/8” Centering Rings (2)
G. Black G10 Fiberglass 1/8 Fins
H. G12 Fiberglass Coupler 8" Length
I. Black G10 Coupler Bulk plates (2) Inner (2) Outer
J. Vinyl Decal

Also From Rocketry Warehouse will be Matching Pre-Packs that Include Rocket Matching 60" Chute, Shock Cords and an Adept 22 Altimeter! Pre-Pack Price TBD.

Check out this huge USLI flight on an L motor



At DTH Rocket

Tuesday, March 13, 2012

Bill Tindall: Tindallgram Memos



"Tindall wrote over 1,100 memos between 1964 and 1970 for both Gemini and Apollo. There are copies of many of them available in several different archives but there is not a complete set.

One of Tindall's friends put together a set of 185 Apollo Tindallgrams just after Bill died in 1995. The University of Houston-Clear Lake Archives has a digitized version of that set on CD.

I know that many NASA MSC workers from the Gemini/Apollo years saved copies of various Tindallgrams they received as part of their work but most of the copies I have seen belong to NASA, the National Archives, or UH-Clear Lake." - Andrew Baird

Tindallgrams 1
Tindallgrams 2

More at Collectspace.com

Sunday, March 11, 2012

Balls 20 - 2011



I think this is the first time I have posted this video. Better late than never! It includes footage of the the 4 Carb Yen, a N5800 - N1100 two stage flight to over 100,000 feet, conducted by Jim Jarvis. This flight, with a slow upper stage and significant staging delay, is the closest test yet of the proposed N5800 to N5800 space attempt that has been discussed here and at The Rocketry Planet previously. The delay was around 10 seconds, with an upper stage burn time of around 10 seconds as well. Now delays of significantly longer, 20 to 30 seconds, were proposed in the space shot. It also remains to be seen how much better an N5800 will do as the upper stage. You can see this rocket fly at 1:00.

You can also see a massive two stage flight by Robert Dehate and the Derek Deville Q flight to about 120,000 feet.

Saturday, March 10, 2012

Neutron star compared to New York City



"This illustration compares the size of a neutron star to Manhattan. The crushed core of a star that has exploded as a supernova, a neutron star packs more mass than the sun into a sphere just 10 to 15 miles wide." Credit: NASA/Goddard Space Flight Center

The crazy thing about a neutron star is that when you look at one side, you see parts of the other side. The gravitational pull is so strong that escape velocity approaches the speed of light. It is not so strong that light is sequestered forever, but strong enough that light is massively bent around the sphere to the other side.

NASA

Friday, March 9, 2012

29mm Minimum diameter Blue Thunder G80T



Loving this build over at TRF

MIRV Warhead Nosecone



Is this what an RV outer shell looks like? Looks kinda short here, is this the forward half that holds the physics package?

Past, Present, and Future of NASA - U.S. Senate Testimony

"Currently, NASA’s Mars science exploration budget is being decimated, we are not going back to the Moon, and plans for astronauts to visit Mars are delayed until the 2030s—on funding not yet allocated, overseen by a congress and president to be named later."

Testimony to the U.S. Senate Committee on Commerce, Science, and Transportation
- Neil deGrasse Tyson

At the Hayden Planetarium Blog.

Thursday, March 8, 2012

Proving the Principle - A History of the Idaho National Engineering and Environmental Laboratory


inl.gov

Q: Hey what is the deal with all the nuclear stuff all the time? Isn't this a rocketry blog?
A: Before rocketry and after kayaking, nuclear power (including weapons) was a major hobby for me. Obviously as an armchair enthusiast only. Old hobbies die hard, and as the Internet expands, the access to nuclear videos and documents is ever increasing.

Wednesday, March 7, 2012

How long can reloadable motors be stored?

What if you assemble an RMS motor and the launch is canceled? How do you store it, and for how long?

Welcome to the B reactor video series





Atomic Heritage has a whole bunch of videos talking about the reactor used during the Manhattan project to create plutonium from uranium. This was one of the first reactors ever built, and as such was a prototype in the extreme. Furthermore, it was a very large reactor compared to the few other experimental reactors of the period. Like everything else with the Manhattan project, this reactor was huge, expensive, and at the bleeding edge of science at the time.

Tuesday, March 6, 2012

Monday, March 5, 2012

Sunday, March 4, 2012

Estes Pro Series II motor retainers - final review

After finishing up the level 2 rocket, I used a bit of JB weld to install rail guides, reinforce the airframe joint in the 38mm Thunderbolt, and mount two of these motor retainers. All in one mix! That is one benefit to using a slow epoxy like JB weld; no rush to finish projects as you use it.

Here are both ends of the retainer on a 29 40-120 case before installation in the rocket. This image does not provide much information but it looks cool.


The retainers were installed on this kit, an unpainted Wildman Dragon, and a Loc Graduator. JB weld was used, but I bet 30 minute epoxy would be fine. Consider the thermal exposure, and also the ability of an epoxy to bond with plastic. JB weld works very well on both counts so it was my choice for this use. I would not use 5 minute epoxy because it is rated to only 200 degrees.

Because these rockets had been built and used long before the retainers were installed, the fit was too tight. Epoxy residue was a factor, and I also gather that fiberglass will always be a tight fit. I did sand the motor tubes a bit, but spent most of my time sanding the plastic tube (threaded portion that is attached to rocket) because it was easy to sand. I made each loose enough to fit, but tight enough to require a tap with the end of a screwdriver on installation.


Here you see the 29mm motor case dropped into the rocket. (Including the obligatory rocketry feet.) The fit will be perfect as long as you keep any epoxy residue out of the tube. Keep paper towels and alcohol on hand for this. My Loc MMA1 (29mm to 24mm) did not fit. It has too much electrical tape on the back to fit vertically (easy to fix) but also seems to be a bit too wide. I can also fix this by removing the outer paper layer. The biggest test of the retainer will be flying this rocket on a 24mm CTI motor with the MMA1 and an F240.


After dropping the motor in, it is quite easy to screw the cap in place. I did not crank down on it as the JB weld is only 12 hours old and I prefer to go 24 hours before any stress is put on a part, just to be on the safe side. Even after the epoxy has cured, I am concerned that screwing too hard could crack the bond (this is plastic after all) and weaken it. So users should decide how hard to screw the unit down and not exceed that amount of torque.

Overall my impression is that these are simple, inexpensive units. If I had unlimited money, I would use slimline snap-ring retainers for all of these kits. But the cost is a bit much for smaller rockets. $20 for a retainer on a $60 rocket... In the past, I simply left the rockets without any retainer and used the time-tested electrical tape method. There is nothing wrong with electrical tape, but this is a bit neater and faster, and certainly looks more professional when you walk up to the RSO table.

If you are interested in purchasing these, I expect they will come online soon.