Monday, April 30, 2012

Just back from DC - The USA Science & Engineering Festival

I have been away this week at the USA Science and Engineering Festival. This is a giant (ca. 3,000 exhibitor) festival that takes place in the equally giant DC convention center A - C halls. Much of the time, I was working, but during breaks I was able to mingle and explore. There were countless different science exhibits covering just about any topic possible, from math to astronomy, from conservation to architecture and robotics. I have included some images, but mostly only those that pertain to aerospace and the general purpose of this blog.  Even after removing most of the images in the set, there are still a ton.  This will be a long post, so bear with me.

Perhaps the most impressive object on display was this, an F-16:

The crew working this exhibit reveled the highly classified power-source:

There was also an Orion capsule used in LES testing:

A Merlin 1 engine was on display in the Space-x booth.  This engine can generate over 125,000 lbs of thrust yet it only weighs about 1,200 lbs!

I was particularly happy to see a high power rocket on display:

This was an impressive level 3 rocket with a 75mm motor mount.  It flew on an L motor a few times, taking good onboard footage during those flights.  The next step will be flying on an N (?!) motor at LDRS at Geneseo.  You can read more about the NCSU team here.

This was a most impressive event.  I estimate that over 150,000 people attended on Saturday alone.  The crowds were almost overwhelming when the Mythbusters got on stage.  To fill a room of this size to capacity, with overflow in adjacent areas of the convention center, is quite a feat!  (I understand that the space was more than 1 million square feet!)  It is great that science is so popular these days.  There were thousands of families with kids of all ages in attendance, as well as visitors from other countries.  Everyone seemed happy to be in one place to share the love of science, math, and engineering.  We even got to see The Magic School Bus!  (It was not configured to dive underwater or into a volcano at the time.)

Let there be no doubt about it: The future of this country is in science, technology, engineering, and mathematics.  Period.  For more than a century we have been leaders in these "STEM" fields.  We are still somewhere on the front lines.  But our momentum is starting to fade.  We no longer have any manned spaceflight capability and it will take years to fix that problem.  The World's most powerful particle accelerator was supposed to be built in Texas.  But then, it wasn't.  And now the best accelerator experiments are in Europe.  The SKA will be built in Africa or Australia.  Republican candidates gain points by turning away from, and sometimes even ridiculing science.  And certain rubes across America reward them for it.  There is nothing wrong with letting science happen in other parts of the World.  Asia and Europe should be our partners in science and technology.  But they should not be our leaders.  I hope that festivals like this may in some small way keep STEM alive in America, and get the kids of today motivated to become the scientists of tomorrow.  Plus, it is always cool to show up and see rocket stuff!  I have more pictures of  projects that each require a full post so that will wait for another time.

Saturday, April 28, 2012

Shuttle lands in New York

Away for the week in D.C... was not able to see this bird take off in the morning, but will certainly visit her when she arrives in Manhattan.

Thursday, April 26, 2012

Cotronics epoxy and ceramic adhesives

As high-end hobby rockets begin to exceed mach 3, and in a few cases even probe the lower hypersonic regime, good conventional epoxies like aeropoxy may not be enough. For certain rocket surfaces, such as fin leading edges, there are a few possible solutions. The most obvious choice is to simply use metal in the fins. Aluminum should be plenty for flights to mach 5, and most space shots. Steel is even better, but only needed in extreme conditions such as boosted dart space shots.

As a sort of compromise,  metal strips could also be used on the fin leading edge to protect the composites below. (Image above is from "tfish" at the rocketry forum.  This rocket was not recovered so the efficacy of this aluminum tape is not known.)  Composite damage to fins around mach 3 seems to arrive in the form of delamination, starting near the fin leading edge. There is little doubt that very high temperatures cause this problem. Metal is a good heatsink, protecting the composites below to some extent.  Metals can spread the heat out, away from the fin edge, and buffer the transfer down into the composite matrix.  Since most rockets only spend a few seconds above mach 3 at most, simply delaying the input of heat may be enough.  Even at high temperatures, I expect that strips of metal would protect heat damaged composites from delamination. It is not heat alone that destroys fins - it is the combination of heat weakening and extremely high dynamic pressures.

 Metals may not be attractive for various reasons, including cost, weight, and machining difficulties. An additional alternative, but one that has not been employed much in the hobby, is ablative coating. Properly designed ablatives are more than sufficient to protect a rocket under just about any flight condition. Just look at the Sprint ABM that could survive dozens of seconds over mach 5. Thick layers of epoxy or high temperature paint can offer ablative protection. But I suspect that these layers should have a suitable opacity to protect the layers below them. For epoxies and ceramic adhesives that can either protect through ablation or actually resist high stagnation temperatures, I think Cotronics is a good choice. A cheap solution would be to build up many layers of JB weld over the edge of the fin. This will resist modest temperatures, and serve the rocket well at mach 2. There are other fairly conventional epoxies that resist higher temperatures still. Cotronics offers some epoxies like this. Those that are most thermally resistant require protracted high temperature cures, something that wont work with composites. (But would be fine for an all-metal rocket with a metal fin can.) Another solution that I propose is the use of ceramic adhesives. Cotronics offers some solutions that may be useful. Durabond 950 cures at room temperature, and is resistant to 1200 degrees. It is thermally conductive, however, because it has metal in it.  This adhesive is not terribly strong, only offering hundreds of pounds per square inch at low temperatures.  Protecting a fin edge may not require that much strength.

I still think that metal fins and motor-as-airframe is the inevitable configuration for all top performance 75 and 98mm rockets in the hobby. This is already known in P-Q motors and space shots, and it would be a natural extension to bring that technology down into level 3. But composites are cheap(er), lightweight, and easy to mold into almost any shape. They will remain the go-to choice for a while. This does mean that fin protection, perhaps with better epoxies, is increasingly important.

Monday, April 23, 2012

"Russkiye Vityazi” (Russian Knights)

"The Sukhoi Su-27 (Russian: Сухой Су-27) (NATO reporting name: Flanker) is a twin-engine supermanoeuverable fighter aircraft designed by Sukhoi. It was intended as a direct competitor for the large United States fourth generation fighters, with 3,530-kilometre (1,910 nmi) range, heavy armament, sophisticated avionics and high manoeuvrability. The Su-27 most often flies air superiority missions, but is able to perform almost all combat operations. Complementing the smaller MiG-29, the Su-27's closest US counterpart is the F-15 Eagle." More here and here.

N flight to 42,000 feet - with some delamination on fins

Some stats: 
-6:1 Fiberglass von Kármán cone
-Featherweight Raven2 (with perch), BRB RF beacon, BRB GPS (all in the nosecone)
-Primary and redundant apogee charges in surgical tubing
-Single 60" section of FWFG tube 
-.093" fins with two layers of uni-directional carbon and one layer of plain weave
-Drougeless apogee with 84" main released via line cutter
-8 pounds empty, ~40 pounds loaded 

Further discussion on TRF


Sunday, April 22, 2012

A time-lapse of Planet Earth

"A time-lapse of Planet Earth, created from images produced by the geostationary Electro-L Weather Satellite. The images were obtained beginning on May 14th, and end on May 20th. The images are the largest whole disk images of our planet, each image is 121 megapixels, and the resolution is 1 kilometer per pixel. They are taken every half hour, and have been interpolated (smoothed) to create this video. The images are taken in four different wavelengths of light, three visible, and one infrared. The infrared light is reflected by forests and vegetation, which appear orange in these images."

 Images Copyright NTs OMZ. Videos Copyright James Drake.

How great would it be to get a small space-station into a geosynchronous orbit like this? Doing so would better test long duration strategies for missions out of Earth orbit.

12" dia. carbon fiber body tubes


Friday, April 20, 2012

Sugar Shot to Space motor casing

This is a scaled-down test motor for the Sugar Shot to Space project. At each step, this team is testing larger motors, working their way up to the full-scale project. This latest development is exciting because it means that the space shot is not too far off. The SS2S team plans to fire a very large (comparable in size to an S or T composite motor) rocket, but to do so with a dual thrust motor. That is, a motor that burns for boost, burns a delay, and then starts burning under thrust again. This helps improve overall altitude, reducing drag and dynamic pressure. Read more about this at Randy's Rocketry and about the SS2S.

Thursday, April 19, 2012

Nuclear Katyusha and Nuclear Verne Gun

"The core idea for the nuclear verne launch gun is simple though dramatic: Dig a kilometers deep shaft—a salt layer would be easiest to penetrate (some exist 3.5 kilometers thick) —build at the bottom a giant shell, from components lowered into place, layer by layer enclosing its internal payloads with external structures (such as a supporting sabot) and sealing the unit to flight-ready status. Place sets of guide rails around the perimeter of the shaft with ‘slippers’—metal contact shoes—touching the rails from the edges of the Wang Bullet. Finally, after all is in readiness, pump reaction mass through an access shaft under the sabot into a prepared chamber and place a thermonuclear explosive device in the midst of the reaction mass."

"The Nextbigfuture nuclear launch gun has been described several times. It is a one pulse variant of a project orion external pulse propulsion system. It is simple though dramatic: Dig a kilometers deep shaft—a salt layer would be easiest to penetrate (some exist 3.5 kilometers thick) —build at the bottom a giant shell, from components lowered into place, layer by layer enclosing its internal payloads with external structures (such as a supporting sabot) and sealing the unit to flight-ready status. Place sets of guide rails around the perimeter of the shaft with ‘slippers’—metal contact shoes—touching the rails from the edges of the Shell. Finally, after all is in readiness, pump reaction mass through an access shaft under the sabot into a prepared chamber and place a thermonuclear explosive device in the midst of the reaction mass. A 150 kiloton version would not violate the nuclear test ban treaties which permit underground nuclear explosions up to 150 kilotons. About 85% of heat energy of the nuclear explosion should be converted into kinetic energy to launch the roughly 3500 ton shell to over escape velocity."

I have serious doubts about these plans, both physically and politically. The so-called Pascal - b test did not, I repeat DID NOT launch a manhole cover to escape velocity, as everyone including whatever jerk runs the wikipedia page seems to think. Anything accelerated that fast would be destroyed, and it was not accelerated that fast anyway. But, these ideas have some merit. This is worth considering further.

The Next Big Future 1
The Next Big Future 2

Wednesday, April 18, 2012

Launching an X-15 from an XB-70

"The proposed X-15A-3 was a stretched, delta-winged version intended for extended duration flight at Mach 6+. As with the X-15 and X-15A-2 versions, the plan was to launch the X-15A-3 from a B-52 underwing pylong. However, North American Aviation proposed launching it from atop a B-70 bomber. The theory was that the B-70 could get the X-15 up to around Mach 3 prior to separation, thus greatly improving the rocketplanes performance."

Um... sick idea! Launching insane things from other insane things is a theme we need to continue. For example, why not get this XB-70 to launch off a giant blimp? More seriously, this kind of strategy comes back around every now and then. It would have been better for the Shuttle orbiter to fly from a reusable aircraft as initially designed.

From APR

Tuesday, April 17, 2012

German V-2 Nosecone on Ebay?

Any experts out there know if this is real or not? It looks really thick and heavy for a nosecone, not sure what I am looking at here!

On Ebay

"Extremely rare WW2 V2 nose cone, the first 16 inches of the rocket, the very apex point, still containing some of the electrical system inside as you can see from the picture of the point. Very early piece of early rocket technology, the V2 was the first successful ballistic missile designed by Wernher von Braun, who later went on to work on the NASA Saturn V moon rocket. Very interesting piece for any space or rocket technology museum display. Has surface rust pitting from age, a few very small rusted holes, which could be plugged, would look better with a coat of protective rust proof paint, it is a very good stable relic from WW2 as you can see from the pictures, looks amazing and would look amazing in a museum display case for a rocket technology and science display for any museum collection. Even the best science museums don't have these rare parts for display, the last one I saw on ebay sold for $2000 in much poorer condition. This one is low priced at only $1030. Postage to the USA is not a problem as you can see from my excellent feedback and gold seller status, I sell a lot of rare items to the USA and worldwide. Very low buy it now."

Shuttle flyover

I am going down to DC for a week, mostly for business, but I have two days off and will spend much of one at the Museum of Natural History, and the other at the Air and Space museum. Will take pics if I remember the camera! Not sure if the shuttle will be visible by next week, but if so, tons of pics.

Four stage rocket - Comanche 4

"This flew at LDRS 29 in June 2010. Total length was 25 feet, 110 lbs. on the pad. Used all Cesaroni motors, starting with a M-2505, K-1085, K-1085, and an L-995 in the 4th stage. Unfortunately, the recovery harness wrapped around the sustainer, the chutes never inflated."

Monday, April 16, 2012

11.5" Little John on a P7200 Green

"At MDRA's Red Glare 12, Ryan Sebastian, David Reese, Andrew Diehl and I flew my 11.5" (stretched) Little John on our 50,000Ns Infinity Propulsion P7200 Green motor. The motor burned for 7 seconds and pushed the 270lb rocket to an apogee of 15,900' at just under Mach 1. The rocket recovered undamaged and ready to fly again right at the entrance to Higg's farm. This flight was the 2nd P flight and 5th flight overall on the Little John. Thanks to all the MDRA leadership for helping to make this flight happen!"


Black Brant nose cone

Friday, April 13, 2012

Found a seed attached to a chair from China

This small seed was found on a chair packaged and shipped from China. It is likely that this seed actually comes from China (though possible that the chair was repackaged here in the US.) The seed was placed in sterile potting medium and incubated on a grow-stand for a few days. Nothing germinated so I gave up. Still, it would have been fun to grow a tree from China. Not that food from China does not come here all the time, and those seeds could be grown as well... but this was an accidental intercontinental broadcast of seed, and it would have been nice to give the little plant a thrill.

Wildfires near New York City

Last Monday was an ideal day for hiking, and I went on a nice 10 mile trip. But this comes at a cost; with the dry weather and high winds, there is an increased fire risk. There have been a bunch of wildfires in the region, one in NJ, one in Harriman State Park, and a huge one on Monday near the Brookhaven National Lab on Long Island. This last one was giant, and I happened to pass about 1 km south of it. It took 30 minutes to sneak up on the fire, however, and the smoke trail was visible the whole time. The clouds of smoke were so large and dark, I had expected to find a major petrochemical fire or some explosion at Brookhaven. The other day, I also noticed some smoke coming from the west over the city, and got a few shots of it. Sadly, I got the camera a few moments too late to catch a jet fly right through it!

I think it was this fire: NJ.COM/NEWS

PS: yes there are trees in Brooklyn...

Thursday, April 12, 2012

Digital Space Art by Terry Sunday

"In the 1970’s, the Martin Marietta Corporation (now Lockheed Martin) in Orlando, Florida, built what is still today one of the most incredible guided missiles ever to fly. The Sprint was a part of the only anti-ballistic missile (ABM) system that the United States ever deployed. Complementing the long-range Spartan interceptor, which was intended to destroy incoming nuclear warheads before they re-entered the atmosphere, Sprint was a short-range screamer with literally split-second reactions. It could intercept any warheads that got past Spartan when they were only seconds from their targets. Ejected from an underground silo by a hot gas generator, the two-stage Sprint accelerated so fast that it would pass a .50-calibre bullet, if fired at the same time, within a second. Atmospheric friction made the outside skin of the second stage hotter than the inside of the rocket motor. It was protected by a thick ablative layer that actually boiled away, carrying the heat with it. Sprint was tested successfully many times at White Sands Missile Range, New Mexico and at the Kwajalein Missile Range in the Pacific. It was beyond-state-of-the-art technology for its day.

This image shows Sprint in its silo. The missile sits on the eject piston, which in turn rests on a ring of springs to cushion the missile from ground shocks. When the gas generator under the piston fires, the piston shoots up the launch tube (stopping when it hits the piston arrestors at the tube mouth) and the Sprint continues out of the cell, literally blasting through the frangible fiberglass, foam and rubber domed cell closure. Tan “wedges” at the missile’s midsection near the second stage fins guide it out the tube. The cutaway shroud near the top of the missile is the “foam sock,” an insulating blanket around the guidance section and warhead that keeps the components at operating temperature at all times."

This is a repost from 2008, but I just got an email from this artist and wanted to share more of his work. Terry Sunday creates incredible artwork based on aerospace vehicles, some real, others hypothetical. This sprint image is probably the most accurate and detailed one available. In my initial post, I wondered about the lenticular covering, and if it served some mechanical or EM protective purposes. It turns out that this was a frangible cover that the rocket would break through, and that there was indeed EM shielding built into the cover by way of a wire mesh in the fiberglass, creating a faraday cage of sorts.

He elaborates further: "The 'double walled, lenticular cover' that you devote a lot of your comment to was a two-part cell closure. The inner part was the actual silo environmental and electromagnetic cover. It was made of fiberglass and wire mesh (for electromagnetic pulse attenuation), and was crisscrossed with an array of FLSC (Flexible Linear Shaped Charge), arranged in a modified 'X' pattern aligned with the missile’s fins. At a specific time in the launch sequence, the FLSC exploded and cut the inner closure into pieces as the Sprint accelerated through it. The outer part of the closure was called the 'foam dome,' and it was made of rigid foam something like Styrofoam. Its purpose was not to protect the silo against the overpressure of a nearby nuclear burst—it was not nearly strong enough for that—but to protect it from the thermal pulse. It was painted white and had a thin layer of rubber bonded to the outside of it, as I recall, that would reflect much of the thermal energy of a nuclear detonation. Essentially, it 'ablated' to carry away the heat, similar to the phenolic-resin coating on the outside of the missile’s second stage. Each bolt head that attached the closure to the lip of the silo was similarly protected by a white rubber cap for the same reason. Since the 'foam dome' had very little structural strength, the missile simply flew right through it. There was nothing but air between the two parts of the closure, and it had nothing to do with 'radiation shielding.'"

There are many other images in the gallery, including this neat RV with lots of physics package details within. These details are hypothetical.