Wednesday, February 29, 2012

Mylar streamers 2 x 41 inches

The rocketry bender continues with two mylar streamers. I intend to use these on mid and high-power flights. The plan is to increase visibility with sporadic flashes from the streamer. If it works, this will be a regular addition to all high-altitude flights.

Tuesday, February 28, 2012

Formula 75 - the fins are in!

The fins have been installed in the rocket. The image above shows some water drops inside, the whole thing was cleaned after a final sanding. After the parts were fully dried, the fins were tacked on with CA, and secured initially with a small application of JB weld. A pour of 5 minute epoxy was used on the centering ring to hold it in place and get epoxy rivets going through the lowest fin holes that I drilled. Slowly, with a 24 hour curing time, JB weld fillets are being used between the fin and motor mount. These will see the worst of motor heat so JB weld is a good idea. For the fin to airframe internal fillets, I will either use 5 minute epoxy or 30 minute epoxy. Strength matters here, but heat exposure is minor. Once this is done, the rocket will be ready for foam, and the centering ring will be installed.

Monday, February 27, 2012

Make your own nebula

Neon Flames

Soyuz images at English Russia

"On Friday, A Soyuz-2.1b rocket carrying a Meridian spacecraft, lifted off from the Plesetsk Cosmodrome at 4.08 p.m."

Many more images at English Russia. This link was provided by Derek Deville.

Sunday, February 26, 2012

Stiga flight 2 - to 95km by Armadillo Aerospace

Recovery on this flight was less than optimal, but it is great to see the rocket performing as needed for spaceflight.

The footage from about 3:30 until reentry shows really cool micro-gravity and a lack of atmospheric drag. One can see a parachute just float around, along with small particles, the nosecone, and recovery lines. This is the look (and silent sound) of space!

A recovery failure appears to occur at 4:59, with the loss of the nosecone and ballute. Clearly spaceflight is hard, and takes practice to get right. Even with minor problems like the ballistic recovery, I consider this flight highly successful. With the loss of this drogue ballute, the main 'chute was destroyed as well. With the rocket now aerodynamically stable again, an high-speed impact was inevitable.

The best part of the video is at the end when the rocket comes in ballistic (and nose-down) for a crash landing. Yes it is sad that the rocket was damaged, but it scores very high on the cool factor nevertheless. It falls very fast, supersonically it would seem. The rocket then lands extremely close to the launch pad. It is good that footage was recovered and no one was harmed by the crash-landing at the end.

"The video and subsequent hardware analysis showed that when a coiled rope extended and created a jerk load, the ballute broke a strap that was meant to retain it until the main was released.

After the ballute left the vehicle, the rocket fell nose-down the rest of the way. The main parachute also departed with haste as the rocket entered the thicker atmosphere. Once the rocket gets below the clouds it provides a good view of the spaceport runway and the gravel mine southwest of the vertical launch area.

Telemetry was regained briefly on the way down as the rocket came back within range. It sent some information on event timings, but unfortunately does not send a latched apogee altitude. Apogee was estimated from the position and velocity curve of the last data received, about 10 seconds before the end of the burn, plus main engine cut-off time and apogee time from the onboard video. The best match to the data is at 94.5km above sea level.

From launch control we heard a sonic boom, shorter than the last flight's, followed by the noise of a rapidly falling rocket. The rocket was spotted, and some of us watched as Stiga impacted the ground at 205 meters per second roughly 750 meters from the launch site. This represented kinetic energy of around 5 megajoules. Everything on the rocket was destroyed, except the fins and engine, which were last to hit the ground and were quite overbuilt."

The nosecone and ballute were recovered about nine miles away! From the picture below, the size of this rocket becomes clear. It is a huge nosecone, and that is not 1 inch kevlar strap as I had suspected, but rather some really beefy 2+ inch strap. They clearly built it up and it still failed! The dynamics of spaceflight are particularly demanding.

Here are a few images from the website:

I am particularly interested in the ballute used for recovery:

I had previously noted that they would be better off going with a rocketman drogue. While I still suggest trying this, it is clear that the ballute is working fine and the real problem this time was a failure in the attachment point. This ballute will possibly be used on the next flight, a new rocket designed to fly to 125 km.

Here is more information about the flight:

Stiga Flight 2

NukeMap - a simulation showing nuclear explosions on Google maps

This fun little simulation shows the detonation of any nuclear device of standard design (no enhanced radiation weapons that I can see) from a list of preset warheads, or any arbitrary yield. While I doubt the information here is perfect, since detonation altitude and conditions would greatly alter the results, it does seem to scale fairly well to at least 100 Mt devices.

The simulation above shows a small Davy Crockett nuclear device of 20 tons yield. One should note that while this is tiny for a nuclear device, and near the minimum yield possible before you get a fizzle, it is still an exceptionally powerful bomb. In explosive power alone, this bomb would be several times more damaging than even a large conventional bomb like the GBU-43/B MOAB. The explosive yield is twice that of a GBU-43, but I also think there would be a hotter fireball and an explosion with very high brissance. Even more significant, as you can see above, is the radiation damage. Very small nuclear bombs do the most damage by radiation when used against humans. Those a few blocks away would survive the blast (as long a flying debris did not hit them) and probably would not even see much of a thermal exposure at all, as buildings would block most of that, but the radiation exposure would be profound indeed. (Unless again buildings could be expected to stop most radiation, something that I do not know much about.) One would have to be 10 blocks away, or about half a mile, to be safe from severe radiation exposure if unshielded by buildings. There is no doubt that this particular target, the Empire State Building, would be completely destroyed and rendered radioactive in the process. A tiny bomb like this would, if used by terrorists, cause billions of dollars in damage and kill thousands of people.

For fun, I also tried huge detonations like a 10 Gt device:

Now I have been told that devices of 100 Mt and higher have limited use as atmospheric detonations, simply because blast is shot upward into space, and because heating is limited with the curvature of the Earth and the atmosphere blocking most of it. Any giant nuclear device must necessarily detonated at high altitudes of miles or more to help spread the heat around. But if they are, the amount of thermal heating can be profound indeed. The Tsar Bomb demonstrated this.

This 10 Gt device above has a large fireball about 20 miles in diameter (enough to utterly destroy and even crater most of New York, the place of detonation.) The blast is also massive, killing most people indoors half way out on Long Island, and killing many people out to the end of Long Island. But far more shocking is the amount of thermal energy that this bomb would produce under ideal conditions. This simulation shows 3rd degree burns as far north as Montreal and as far south as South Carolina. Clearly such a bomb would be very difficult to build, and would only be deployable on a large ship. Detonating at sea level from a ship would ruin the point of using such a large bomb in the first place for the reasons I discussed above. Only fallout would be enhanced with a sea level detonation, and the fallout from a 10 Gt blast in New York would be severe enough to harm millions of people as far as Russia, though at a time of nuclear war, the fallout from distant detonations would not be a priority. Far more economical is to simply use many smaller warheads of 200 - 900 Kt yield as is the case here:

Saturday, February 25, 2012

Back from vacation

After a week away in Louisiana, it is both sad to leave and great to be home. It certainly helps if you get home and find a tiny box by your door that has these two inside:

I am very happy to report that two of the new Estes plastic retainers have arrived. These are called "Pro Series II" retainers, and are designed for 29mm mid-power rockets. Each pack has two threaded tubes and two screw caps. This means that each pack is good enough for two rockets! (Or perhaps one with spares.)

I will install them on my two 29mm rockets soon, and post again with more information. For now I can say that they appear to be strong, but not terribly heavy. Basically they feel like PVC fittings of this size should feel. The color is a neutral grey, and will match the JB weld pretty well.

Great hotel deals at

Monday, February 20, 2012

Formula 75 build continues

Construction on the new kit continues apace. First, the upper centering ring was notched to allow the kevlar line to fit between it and motor tube. The kevlar was epoxied to the fiberglass motor tube, as was the centering ring. During this step, I selected JB weld for heat resistance. I do not know (and doubt) that this is significantly better than 30 minute epoxy even in this demanding location. 5 minute epoxy (used at times in this build) is rated for 200 degrees temporary. So I suspect that 30 minute epoxy would be fine. Only with the slimline retainer do I suspect 30 minute epoxy would be at risk. As previously stated, I don't really worry about appearances for internal parts, and the JB weld was just slapped on without masking tape. Most important is that coverage is complete and that all parts of the joint are covered on both sides. This was left for 24 hours to cure.

After filling the nosecone with expanding foam, the bulkhead plate was installed first with a thin layer of 30 minute epoxy, followed by a large (22.5 grams) pour of 5 minute epoxy. This potted the unit in place very securely, and also helped reinforce the edges of the nosecone to prevent damage if there is impact with the airframe. I enjoy using 5 minute epoxy when possible because it can be whipped up with air bubbles and remain fairly light, good for filling spaces like this. It does last long enough to settle flat after 30 seconds of mixing and a pour. The fins will be potted in place using more 5 minute epoxy after JB weld fillets. 5 minute epoxy is also quite cheap, and is less brittle than slower curing epoxies. This may mean weaker, but can also mean more impact resistant.

Urban wet-sanding may not look very professional, but it gets the job done. There is no safe way to dry sand in an apartment without a dedicated work-area. The results are better anyway, and cleanup is pretty simple. Fin slots and other contact areas were sanded for fit and better adhesion. These fin slots are very tight, and it looks like alignment will be almost automatic as a result.

After ca tacking the motor tube and upper centering ring into the airframe, the rear centering ring was installed as you see above. This ring will be removed after the fins are tacked in place, so that the fins can be reinforced fully. The nylon line (once a shock-cord from a rocket) has been tacked with ca so that the centering ring can be removed later. The alternative was to drill two small holes, and this strikes me as excessive. Once the ring is removed, it can be flipped over so the ugly side is facing in.

The fins were test-fit into the rocket, and taped off. The roots were all wet sanded (this time in the sink!) first with 400 grit, then 150 grit. The 400 grit was used to remove all residue of a sticky material that was found on the fins, possibly used to hold fiberglass sheets together while cutting. I found this material particularly hard to clean off. First it took razors, then scouring in hot water and soap, and finally the 400 grit when nothing else could finish the job. (Yes even alcohol was tried. No acetone or goo be gone on hand.) The 150 grit is to prepare the fins for epoxy. It should be plenty considering the amount of epoxy and foam about to be used.

The fins were then stacked, taped together, and placed on a visco-elastic foam sample block. I used a dremel and 1/8th inch bit to drill 8 holes along the root. These holes were at no time closer than 1/4th inch to each other or the edge of the fin, hopefully preventing any cracks or weakness in the fin structure. These holes are concentrated at the front of the fin and rear. In the front, 5 minute epoxy will pour through the holes (one fin at a time) and help form rivets. In the rear, epoxy foam will extrude through the holes also. Or that is the idea anyway. This may be overkill, but I intend to use a 28 inch skyangle 'chute with this 5 lb. rocket and strong fins are an absolute requirement. Furthermore, I do not plan on adding any significant fillets to the outside of the airframe because it will not be painted. Perhaps only a tiny strip, but nothing structural. Therefore, all fin strength will come from within the rocket.

Today I will attempt to fit and tack the fins in place, and perhaps even do the JB weld fillets. The rest will have to wait until after vacation. But the good news is, this rocket is more than half done! It will be ready to go by the first launch.

Thursday, February 16, 2012

Icarus Rocket Launch

Icarus Rocket on-board video from the 2011 ULA Intern Rocket Launch event in Pueblo, Colorado on July 30, 2011. Includes both real-time and slow-motion replay. Max altitude ~4000 ft. Video shot from on-board GoPro HD Hero payload designed and built by George Mitsuoka. Icarus Rocket designed and built by Steve Dean of United Launch Alliance.

Wednesday, February 15, 2012

Future of Aerospace Rocket

"United Launch Alliance (ULA) Future of Aerospace Rocket: United Launch Alliance, Ball Aerospace Interns and High School Students Launched Colorado's Largest Rocket, Payloads, Saturday, July 30, 2011 from a launch site near Pueblo, Colorado.

Interns from both companies--representing the future of the aerospace industry--built the high-power rockets and a variety of multi-faceted payloads this summer as part of their experience at their respective companies. A major new addition to this year's effort has been the work of 14 teams from 11 Colorado high schools, laboring for months to develop payloads to launch on the rockets.

The Future of Aerospace and Stars 'N' Stripes rockets were built by ULA summer interns-dubbed SPIRIT (Sky Piercing Intern Rock-It Team)-in Denver, Colorado, Decatur, Ala., Harlingen TX, Vandenberg AFB, CA, and Cape Canaveral, Fla. This is the fourth year ULA interns have built and launched high-power rockets as a summer project and the second year with participation from intern at other ULA work locations.

United Launch Alliance (ULA) Future of Aerospace rocket
Launch Date: Saturday, July 30, 2011
Launch Site: Hudson Ranch, 9.5 miles west from the Walmart (at Pueblo Blvd.& Hwy 78) on Beulah Hwy. It is located on the right side coming from Pueblo, Colorado.
Length: 25 ft
Weight: 300 lbs
O-Class Rocket*
Altitude: 10,000 ft AGL
(1) large, (1) medium, (12) small payloads"

More at TRP

Tuesday, February 14, 2012

The Shadow - first two flights

Regular readers may remember a previous post about a water rocket that is built like a HPR rocket. The rocket flew twice, once with good recovery and once with a failed recovery. Both flights were very fast and achieved about 1000 feet apogee. Most impressive is the amount of thrust, and the short duration. This rocket shows similar performance to a G250 motor in my estimation. Acceleration was around 50 gs, which is more than most high power flights. It is possible that the motor was faster still, perhaps something like a G400. More data would be interesting to find out exactly what thrust and impulse this motor puts out. Here is footage of the two flights:

You can see a detailed flight report here.

Monday, February 13, 2012

Project Pluto Nuclear Ramjet Cruise Missile

Finally a video of the Discovery Channel Wings episode for Project Pluto! The following are parts 1 - 5 of the show.

Let me know if there any playback issues with this video provider.

There is a poor partial video on youtube as well.

There are, however, good copies of the "Nuclear Airplane" and the XB-70 episodes on Youtube proper:

I want to thank Sheldon for sending me these videos. If any readers have something interesting to share, please email me or post in the comments.

Extreme Performance Rockets (from 2007)

These are oldies but goodies, and a few of them are newies to me. Including these two:

This rocket looks like a giant egg lofter (perhaps for ostrich eggs?) but is actually a 6 inch can-sat launcher with a minimum diameter bottom for 4inch motors. This flyer is the king of low-weight altitude rockets, and this one is no exception at about 10 lbs empty. That is not bad at all for a rocket with a 6 inch payload.

The specs for this rocket are insane:
LOA: 150 inches (about 12 feet)
Booster: CTI Pro98 N2500 (5.5 second burn, 13766 newton seconds)
Sustainer: CTI Pro98 N1100 (12.2 second burn, 14044 newton seconds)
2nd stage burnout: Over 1700 mph
Expected apogee: Over 90,000 feet

This is an excellent initial test of what two N motors can do. There is no doubt that, even without staging delays, N motors can break 100,000 feet in a well built, but largely conventional rocket. Replacing the first stage with an N5800 motor would increase the build requirements, but would probably have been enough to push the design past 100,000 feet. With a 10 second staging delay, one wonders how much the apogee could be increased again. The question remains, can two N motors launch a rocket to space with the right staging delay? Projects like this are a good way to test the waters first. Clearly the choice of motor is all important. Non-optimal O motors (like the stubby CTI O motors) and skinny M motors like the Ellis Mtn M1000 have been used in 100,000 foot attempts. Yet similar performance is possible with two N motors when motors like the incredible N1100 are employed. Two N1100 motors would be very interesting to fly, but the risk of the rocket drifting into horizontal flight are greater. At very low thrust, fin thickness can be held to a minimum as can airframe weight.

Additional Rumpty Dumpty information at TRP

XPRS Gallery from 2007

Sunday, February 12, 2012

The 5th Annual International Rocket Weekend, 1996

The 5th Annual International Rocket Weekend

August, 1996

Kelburn Country Centre, Ayrshire, Scotland.

I came to this page searching for an image of this rocket:

The Comanche 5, that supposedly flew on a D12 - D12 - C6 - C5 - C6 to 4,000 feet! This image shows Marcus Lauder, the builder.

Saturday, February 11, 2012

Design X - Icelandic student project

Amateur Icelandic rocket to about 1400 meters.

There are also many construction and post-flight images here:

As well as images of propellant cooking:

Here is a crude translation: "Design - X is not yet complete, although the last Wednesday it was oral examinations have been completed in the course and with all the work that the students had to deliver us over. but less than that, this is not yet over. In the evening on Wednesday went Rubber, Sector Deficit and the Svalbard component shown on screen simultaneously. They were there with great excitement in the scientific corner with him Helga from Leaning Tower. The show was shown on Friday and the boys were good and were both themselves and the school with distinction. But those who have yet to see the episode when he presented tonight at 00:20 or so on Monday morning at 19:10. I recommend you check out the episode, since this is also a very entertaining episode. Following nook that was a fraction of all the major media in the country, the well has been taken in the event. Subsequently, there were 3 members of the group asked to bring in aspects of Svalbard as it was said by earlier. But now next on the fact that I Gudmundur city and Kari Rafn are going to give a lecture on aviation conference that starts next week and will be in lecture on Wednesday. I Kvet all those who want to see me sweat please come and witness the wonderful items. There will then be announced later on the exact timing of this lecture, but until then, then I pray that heylsa. Yours Gummi"

Thursday, February 9, 2012

Horse gas masks

Many people seem to visit this page after searching for "horse gas mask" or other similar google searches. So here are a few more.

Wednesday, February 8, 2012

Drops of water orbit a knitting needle in space

"Expedition 30 astronaut Don Pettit uses knitting needles and water droplets to demonstrate physics in space through 'Science off the Sphere.' This is part of the first video in a series for a partnership between NASA and the American Physical Society to share unique videos from the International Space Station with students, educators and science fans from around the world."

Monday, February 6, 2012

Work on the formula 75 - nosecone

I have scuffed up most of the epoxy ready surfaces, other than airframe. These were all cleaned with soap and hot water, then carefully dried. Instead of purchasing a nosecone eye bolt as planned, I decided to use an extra Giant Leap 38mm anchor. This includes a strong eye bolt system as well as a 38mm aluminum tube. It is certainly overkill, but the plan is to just use the entire thing with the bulkhead at the center. I then made a small mix of 30 minute epoxy and locked the whole thing together. The application of epoxy was sloppy, but because this is an internal part I did not really worry about making it look perfect. The most important parts were all coated, including the nut, washers, threads, and the actual 38mm tube with vanes. This should help protect from off-center impacts on recovery, and will spread out vertical pull on the nosecone, but will ultimately not make a huge difference over a naked 1/4th inch eye bolt.

The bond strength of the bulkhead, or possibly the open eye bolt are now the weak points of this small component. This will be potted in place with a large epoxy pour of no less then 1/4th inch thickness at a later point. I expect that this will allow for an extremely strong nosecone assembly.

With the rest of this epoxy, the nosecone shoulder was installed in the base of the nosecone. This strikes me as a weak-point because the nosecone is so heavy. Therefore, it will be reinforced with epoxy, and later with a full volume of expanding foam.

No images of the nosecone shoulder were included because with black on black fiberglass, the contrast is too low.

Building, flying, and attempting to recover a 98mm min. dia. rocket

"98mm hand layed fiberglass rocket flying on a N1397 motor"

"Tuff Enough..98mm min dia hand layed fiberglass rocket flying on a N1700 Swamp Gas. Flew to 37K 2.2 mach"

Recovery of hpr rockets is always difficult, and the challenge grows exponentially as altitude increases beyond 10,000 feet. My longest recovery was also at Black Rock, but in my case the rocket was small (2.5 inches by 72 inches) and the distance was only about a mile or maybe 1.5 miles at most. We lost sight of the rocket on the way down, but did know the general location. After driving out a ways, it came back into view on the ground and was recovered no problem. Flights to extremely high altitude, 50,000 feet and beyond, frequently fail during thrust, at max Q, on recovery, or they get lost somewhere on the ground. It is very difficult to get everything working perfectly.

Discussion and information can be found at The Rocketry Forum.
Also check out other videos (inc. construction details) at the tfish38 channel.

Sunday, February 5, 2012

Hydrogen peroxide engine on Ebay

Thrust - nominal 50lbs with 85-90 % hydrogen peroxide
Design Chamber Pressure - 300psi
Material - seamless 347 high temp columbium stainless steel.
Weight - 380 gram +/- 1 gram
Outside Diameter-- 1.500 inch +/- 0.002"
Inside Diameter -- 1.365 inch =/- 0.005"
length ~ 4.5 inches total


Formula 75 rocket kit has arrived

This kit will be my level 2 certification rocket. The Formula 75 is about 75mm x 48 inches with a 38mm motor mount. It is all fiberglass, including the highly impressive nosecone (more on that in a moment.) The kit arrived in a bag with the basic parts only: a nosecone with shoulder and bulkhead plate, pre-slotted airframe, motor mount tube, and two centering rings. No parachute is great, I already have too many. But it also lacks any Kevlar cord, motor retainer, rail guides, fin bevels, or most importantly any nosecone hardware such as an eye bolt. This is the price you pay to get a large fiberglass kit so cheaply, $95 shipped in this case.

I plan to get the additional hardware at giant leap, at a not insignificant cost (about $35) including 15 feet of 1/4th inch kevlar and a slimline. Even so, it would have cost more to go with the other kit I have been considering, a 4 inch dynawind kit from Giant Leap. And this kit is solid fiberglass, and comes with pigmented fiberglass. I have never loved painting rockets, largely because I live in an apartment and there isn't any great space for painting around here. With that convenience does come one condition: the fillets must be clean from the start with no hope for sanding as that may alter the smooth appearance of the airframe. Some amount of conditioning can be achieved with car wax and buffing with a rag.

The nosecone is particularly impressive. It is quite long, and made out of very sturdy fiberglass. The tip appears to be graphite composite. Aluminum tipped nosecones are also available, at a greater cost. The lack of eye bolt hardware in this kit is the only thing that surprised me. I do not think it would add much cost, and is not likely to be customized among most buyers. In any event, a trip to the hardware store should get 'er done well enough. I will go with a forged eye this time, despite never seeing the normal eye bolts fail. A recent thread over at the Rocketry Forum (not the first) has made me paranoid.

This will be my level 2 kit, but will only fly on small 38mm J motors from CTI such as the baby 648ns J285 with an 8 second delay. This motor is so close to an I, I think there is a very good chance of recovery on a day with low wind. That is important enough that I may put off a certification flight depending on the conditions of the launch day. Expected altitude is about 1,800 feet on a J, based on preliminary simulations. That is high, but not excessive for a rocket of this size. (The size affords greater visibility in the air and after recovery.) I specifically decided on a dark airframe color, which I find is better for tracking in the air. On the ground the "cherry" color - really some shade of burgundy, will not do so well. That is where the parachute and possibly a large streamer come in.

I want to built it strong as always, with an eye towards extreme, even excessive strength in some parts. The added weight will be welcome to keep apogee reasonable.

She wont fly dual-deploy, but will recover on a small skyangle that is normally reserved for the much lighter Loc Graduator and H45 kits that are only about half the weight. Extra weight will come with the use of epoxy internally, as well as foam in the fin can and perhaps the nosecone as well. I doubt that nosecone foam will add any significant strength, but I like it simply as additional weight and a way to remove the worry of air-pressure in this very large nosecone. In the fin can, I plan to drill a few holes in each fin root, and arrange to have the foam extrude through these if possible. A strong nosecone bolt, as well as a nice potting of epoxy in the nosecone shoulder and over the last centering ring should round out the rocket at 4 or even 5 lbs total. There will be further updates once construction starts. Stay tuned!