Warning: Fireworks can blow up your mannequin's head

Via the Consumer Products Safety Commission's (CPSC) Fourth of July fireworks safety conference near the National Mall in Washington.

Shuttle-to-DIRECTv3

Just ran across the YouTube version of the v3 animation:

Presenting the Stink Bomb

Here's my paper mache version of the Toypedo rocket. The quality of the surface stank from the start and continued to deteriorate as, I guess, the middle layers totally dried. I started to try to clean it up but ended up throwing in the towel.

I then started wondering about paint and a name. Motivated by the movie Caddyshack. I was thinking about painting it brown and naming it Is that a Baby Ruth in your pool? Or, maybe just Baby Ruth. I found that my existing brown paint was unusable and went with a camo scheme. The name became Stink Bomb.



I think I'll fly it out of a section of window tint tube, which is just a bit larger than standard 3" tubing.

High speed video of the inside of a water rocket

Air Command has acquired a Casio Exilim FC-100 and have documented the dynamics inside the chamber of a water rocket. Cool!

A look at the Max Launch Abort System

You can read about the actual Max Launch Abort System over on ZZakk's Lab. I've seen several people wonder about this thing's static stability...and it ain't good. Luckily, professional rocketeers can apply active stabilization. Here's a quick-look at a 1:72 scale version. Methinks some added clear fins might be in order.

From rockets to rocks

Steve Jurvetson has handed over the reins of the Photo Synthesis blog. That means no more rockets there for now. The latest post explores Rocks that ROCK!

RockSim vs Barrowman vs the Toypedo (update)

Last night, I was making a RockSim model of another strange design (more later) and ran into the often asked question: RockSim or Barrowman? As an aside, RockSim can either compute the CP using the venerable Barrowman equations or using a proprietary method that accounts for some additional factors omitted from those equations. Anyway, RS Version 9 defaults to Barrowman, even when you add things that can't be simulated using that method. In this case, I remembered to select the RockSim method. However, it made me think that I didn't do so in the design of my Toypedo. Although there are no components that shouldn't work using the Barrowman setting, it appears the program was in fact barfing on it. That explains why I was getting CPs ahead of the model with the 'stock' fins. I just changed the setting and now the CP with the stock fins is about in the middle of the rocket...a result which seems reasonable in my meager experience.

Update: What timing! The differences between the Barrowman and RockSim methods are the subject of the latest Apogee Newsletter (#238).

Toypedo update

Well, since my last Toypedo update, I formed two paper mache shells and am building a rocket from them. It is going to be ugly with a capital UGLY. I may or may not reveal its ugliness.

Although they are the way to go, I'm not going to be building a fiberglass version any time soon. If I need fiberglass for some other reason I'm buy enough to try again. For now, meh. I hope the latex mold doesn't deteriorate too fast.

I mentioned before that RockSim showed the basic Toypedo to be very unstable ('off the chart'). I think very unrealistically so, but was planning larger fins anyway. Ken from ZZakk's Lab suggested adding a ring tail. I did so and that works out great. I attached an image from the sim below. Please note two things. First, the CG is not intended to be anywhere near accurate at this point. Also, adding a ring tail requires that you add standoffs to the body...which RockSim includes in its results. If you add fins on top of another, the program will use both to compute stability, so this model's GP is a bit optimistic. I removed the V2-like fins and the CG barely moved so, again, this is close enough for now.

If ya' don't bring your battery...

...ya' can't take photos of your day on the Chesapeake.

OpenRocket - a new rocket design/simulation package

OpenRocket is a free, Java-based, open-source simulator program. It features graphical design, 6-DOF modeling, wind simulation, and graphing. The software was written by Sampo Niskanen for his Master's thesis at the Helsinki University of Technology. Hat tip to Clark 'Space for All' Lindsey.

Virtuality goes boom 183 times (or something like that)

I have been watching Virtuality, a sci-fi TV movie on Fox, and didn't take note when the name Orion was first mentioned. I was later surprised when I heard that the ship, the Phaeton, was powered by nuclear pulse detonation, ala the 'real' Project Orion. This played a very minor, almost unnoticeable role in the show, but I thought it was interesting nevertheless. Despite the fact that the structure of the ship didn't seem appropriate for such propulsion, the pusher plate seemed flimsy, and the bombs were manually transferred to the ejection mechanism. Oh well, back to watching.

Lensman is coming to the big screen...YES!

io9 reports that efforts are well underway for a Lensman movie. I'm not a huge sci-fi novel fanatic, but E.E. "Doc" Smith's Lensman series is my second favorite after Dune. That means a screen adaptation will could either become one of my favorite movies or suck big time (unfortunately, the treatment of Dune fell more in the latter category). Having Ron Howard as the producer bodes well for the movie. J. Michael Straczynski (Babylon 5) is the writer and those more in the know seem to think this is a good thing too. I look forward to epic space battles along with the development of the series' mythology. I am wondering how far into the series the movie will go since actual Lensmen don't show up in the first book, Triplanetary. By the way, Triplanetary is available for free from Project Gutenberg. I guess I'll be digging out my hardcopy as the premier date looms.

When it's 3th and long, you sometimes fall back to Plan B

And, for NASA, Plan B is Shuttle-C (still? again?). ZZakk's Lab point's out that the timing of this realization is odd. That is, it was revealed during the Augustine Commission's review of Ares I. Take that Team Direct.

I'm shaking my head. I am sure there is a down side (there always is). However, at first glance this make too much sense. I probably should watch the latest SpaceVidCast.

Clark Lindsey has a bullet-summary of NASA's presentation, which indicates their current approach is not exactly Shuttle-C. More on DiscoveryNews.

The way I'll remember Farrah

An add to the Internet etiquette guide

When tagging uploaded photos, don't apply a keyword to every photo just because it applies to one of them (or even a few). This will not help you find the photo(s) in question and will piss everyone else off.

(Of course, people on the Internet generally don't care if their actions piss someone else off. In fact, knowing that just encourages their bad behavior.)

Nuclear DC-X RockSim model

BT60 based, 18mm mount, plenty stable

First Toypedo half-shell: FAIL (update)

I tried 2 layers of light fiberglass and used the Toypedo to compress the fiberglass against the mold. The quality is bad, but I guess not that bad for a first try. I need enough cloth so I don't scrimp. I also need to fill the bubbles in the mold. Finally, the strength is poor so more layers would be needed. I don't know what I was thinking on that last comment. With support provided by a motor mount/rings and a nose cone shoulder, it should be plenty strong enough.

I'm thinking about trying paper mache next.

A RockSim model shows stability is an issue with the stubby fins, so I'm also thinking about not forming the fins when using the mold.

Toypedo, extracted

There are a few minor flaws, but the mold turned out OK. Hmmm, I wonder if I have enough scrap fiberglass to build a shell?

Nuclear DC-X

I posted links to the source article earlier today, but thought I'd capture the diagram of the proposed Nuclear DC-X/LANTR SSTO Heavy Cargo Lifter. Another diagram shows this vehicle in scale next to the Saturn V and Shuttle. This would be an interesting build.

Big day in the RLV and Space Transport News

More missile-aneous stuff from Clark. Haven't read them...yet...

• Asabooster CD004 (pdf) - "a conceptual design for a [VTHL] reusable rocket vehicle able to lift 152 lbs with a total delta velocity of 10000 feet per second vertically (not taking gravity and aerodynamic losses into account)"
• Asabooster CD005 (pdf) - "an examination of a Vertical Takeoff Vertical Landing (VTVL) rocket design for a reusable rocket vehicle able to lift two upper stages weighing a total of 163 lbs on a trajectory suitable for a 115 mile altitude orbit. The expected payload delivery to orbit is about 5 pounds".
• X-15 goes where no craft ever attempted - Alamogordo Daily News - June.21.09 (via spacetoday.net).
• Spaceport America's press release about the WK2 fly over: Virgin Galactic Mothership "Eve" Flys Over Las Cruces - Spaceport America - June.22.09.

Breakthrough propulsion references

Picked up from Clark Lindsey (I musta been snoozin' as I missed the Next Big Future posts):

• A 2004 Air Force report Advance Propulsion Study (pdf)
  
• Nuclear DC-X : Recent Nuclear Thermal Rocket Proposals - Next Big Future - June.17.09
• Blast Wave Accelerator: Space Launch System - Next Big Future - June.17.09

Mold making madness

I found a suitably sized cardboard container and lined it with plastic to contain the liquid latex. I also devised a method to suspend the Toypedo over the mold. Earlier, I had checked the volume of material required but I obviously didn't hit 'recalculate'. Mid-stream (the stream being the mixed latex being poured into the mold) it was clear I didn't have enough. My wife helped out as I scrambled to adjust. I changed the height of my supports, inserted some wooded shims at the edges, and poured lead shot into the mix. The latter sank in nicely. I finally raised the level to where I needed it. I just hope the shot doesn't muck up the mold too much as it settles. Oh well, I do the best I can with half a brain. I'll let it cure until morning and see if I can extract the Toypedo.

How to behave on an Internet forum

As an ex-TRF moderator, I just couldn't resist posting this video. (hat tip to UncleVanya, a mod on Rocketry Planet).


Internet: Useful Tips: How To Behave On An Internet Forum

Rocket Girls #74

At LDRS-17:

Playing lawn darts?



I want some of this lawn furniture for my backyard!



I'm conflicted about NSFW material, so that's it for now...

HPR on "The Space Show"

Mark Canepa, author of “Modern High-Powered Rocketry”, will be this week's guest on Dr. David Livingston's The Space Show.

"It’s been far too long since any human visited the place."

The post title is the last line of Taylor Dinerman's article in today's space review entitled Why is it so hard to go back to the Moon? He points out the political, and funding differences between the '60's and today. And that it will likely be 51 years between the last landing and the next (at least for the good ol' US-of-A). Like most space enthusiast, this totally boggles my mind.

What popped into my mind is the risk aversion that we seem to have in our society today. After the tragic Apollo 1 fire, there was a 21 month delay in our space program. After Challenger, the delay was three years and after Columbia it was a bit over that. But it is not the differences in these time frames that I wonder about. If you look back at the early days of space travel, there were so many close calls that were taken in stride. I wonder how many of these would spawn congressional committees if they happened today. This makes me worry if we can ever get there from here...again.

Toypedo rockets, maybe

After many years, I recently found our Toypedo. Its V2-like looks screams rocket. I also recently got an online coupon from Plaza Artist Materials. I seldom buy anything there but I needed some more thin masking tape so I printed the coupon and popped over. I left with my tape and some 2-part latex mold rubber. I'm going to try to make a half-mold of the Toypedo. I figure the probablity of success is high...but the probablity of success making rockets is lower. Time will tell.

Rocket rebuild

I recently dusted off one of my oldest scratch rockets from my early BAR days. The body is a 2" mailing tube, the nose cone is balsa turned on a hand drill, and fins were made from scrap wood from a doll house kit I assembled for my daughter. When I looked at the fins and gasped. After a couple of rounds of reattachment, they were really spaced terribly. They were straight so the model would fly fine but I decided to rebuild the lower section. After disassembly, I realized that I don't have a BEFORE photo. Oh well, this is it now. (The funky spot on the cone is a glare issue.)

99G74 completed

Here's the complete motor, showing the epoxy plug. I borrowed an idea from the world of PVC sugar motors and drilled holes in the case above the grain. These provide glue rivets on the plug. (click the tag to see the previous post)

Photo hosting hiccup - fixed

Blogger experienced a photo hosting problem that zapped some of the photos that I loaded during the middle of last week. They should all be back now. My thanks to Chrisn for commenting. Without people letting me know, problems like this could go unnoticed for a long time.

The Telstar song

I saw this on Clark Lindsey's Space for All blog. Aside from the significance of the song, it provides a nice montage of space exploration photos:

We Choose the Moon

This should be cool. For 4 days starting on July 11, We Choose the Moon will provide a real-time audio and video recreation of the Apollo 11 mission. There are various ways to share and follow the action. I added it to my Twitter feed.

Saturday 06.20.2009

The NARAMS ECRM launch was on despite the threat of rain and afternoon thunderstorms. The weather reports looked like there might be breaks in the rain so I staged my stuff last night. This morning I decided to bag it anyway. It was poring here so loading the SUV would be delayed. Then, I figured the field would be nice and soggy even if the was an occasional ray of sun.

One thing I did last night was assemble my first 24/60 F35 reload. I hit one snag. The instructions say the delay spacer was black cardboard but the kit has a small o-ring. It seemed suitably sized but thought I'd double check before I flew it. I emailed AeroTech and posted on TRF. Donaldsrockets got back to be with a link to AeroTech's asembly drawing for the motor...which shows an o-ring. Non-problem solved! (Well, the instruction error is still a problem, but at least I'm good to go.)

It's pouring again.

I'm going to venture out for lunch and to buy some more thin masking tape (1/2" or smaller), which is a staple in my rangebox.

(and I'm working on my 2nd set of 3000)

3000 posts = a lot of hot air

I just noticed my previous post was number 3000. It appears I'm doing my share to raise the noise floor of the Web.

A rocket for the desktop..a wooden desk, not the one on your computer

Check out this cool General Dynamics 'nut dish'. Photo embedded from Telstar Logistics; originally seen on Dinosaurs and Robots.

It's not 'research' but what is it?

Last year, I ordered a 3-pack of F24 RMS loads that was missing a ton of parts including 2 of the 3 delay assemblies. I contacted AeroTech and, after emailing some evidence, they promptly replaced the reload pack. I quickly decided that I really liked this motor. Later in the year, I picked up two 3-packs of F39's on the cheap from a hobby store that was closing. It soon dawned on me that, with the grain and nozzle, I could use the F24's for my Hat of Death or Whirlygig-24. I salvaged the rest of the components from the F39's and flew the F24s. All I needed was a complete delay column, it didn't matter that the delay grain was the wrong one.

However, I now had extra F39 grains and nozzles. I previously had good success repackaging grains from a G77 reload, one at a time, into an F20 LMS case. So, I wondered if I could go the other way by taking the two F39s and making nominally a G78.

I'm a tube pack rat and found a convolute wound tube that fit the grains, less liners, perfectly. Could I be so lucky? Yes! It also fits perfectly in a spent 29mm SU case. I took a used Ellis Mountain G case (I told you I'm a pack rat), whacked off the forward end, cleaned it out, and I was on my way.

Since chamber pressure is proportional to the propellant burn area divided by the nozzle throat area, all I had to do is double the throat area. Luckily, the required diameter is a skosh over that of the eroded throat of the used motor. But, this is still an experiment. I know how to size nozzles vs. core area, but have no rule of thumb for slotted grains like those used in the F39s. But what the heck, all I'll be risking is a saucer.

Attached is a photo of the components so far. I cut the liner, which is about as thick as an Estes E9, a bit long. I'm going to epoxy in an internal plywood bulkhead (shown) and then add an outer epoxy plug.

I figure this will be close to a 99G74 (using actual the tested F39 numbers vs. the marketing ones). It should fly at MDRA's July launch.

APCP cost may be rising

Rocketry Planet has learned that, due "increasingly limited supply" of surplus ammonium perchlorate (AP) and the "serious decline" in the quality of surplus AP, AeroTech has announced they will be immediately adding a 10% surcharge on all dealer and distributor motor orders. The MSRP remains the same, so we'll see how much of the increase is passed along. You can read many opinions about the why's and wherefore's on the associated RP thread.

I am wondering is this is related to Ares-I motor development/testing and, hopefully, this will be temporary. I do find myself wishing that I'd stocked up on some more mid-power stuff during Hobbylinc's spring sale. I guess this might be good for Quest's black powder 'F' motor if they come out in a timely manner. If nothing else, this consumer will be more likely to spend more on them. It will also be interesting to see what the other motor vendors say.

What's bumping around in my empty head is based on the last post in that thread, which asks at what point will the cost of motors drive people from HPR and therefore kill it. Specifically, I began wondering how many HPRers are really die hard rocketeers vs. mere adrenaline junkies. I am the prior and, while I missed flying HPR, my response to the (now rescinded) BATFE regs was merely to fly the smaller stuff. If faced with availability or family budget issues, I just fly smaller stuff. The answer to my question of course doesn't answer the original poster's question. In my definition, if a true rocketeer can't afford 'J' motors, they will fly 'I', 'H', or smaller. An adrenaline junkie may quit the hobby. In either case, less APCP will flow from the manufacturer to the field. So, the right question may be, "what's the smallest distribution of HPR motor use that can support the current vendors (or any vendors)"? [/rambling mode]

ACK!

The forecast for tomorrow's launch now calls for a 80% chance of thunder bumpers. Well, I shouldn't complain. The first 3 launches of this year were perfect and all of last year was great.

My Massive Gassive was featured in the EMRR Corner

EMRR Corner, a regular feature in Apogee Component's Newsletter, highlights rocketry material from, as expected, EMRR's site. The theme of Newsletter #235's EMRR Corner was Let's Cluster Some Motors. The center photo in this Corner shows the business end of the still unpainted 10 x 24mm Massive Gassive. (BG)

This rocket has flown three times (twice on 10 D12s and once on one E9 and 9 D12s). On the first flight, the heavy nose cone drag separated and caused a massive zipper. I rebuilt it and now the cone is tight. I also now use separate 'chutes for the cone and body.

(as seen on The Essence of Essence's Model Rocket Reviews)

Project 463 construction details

For historical purposes, I decided I'd capture some close-ups of the beast. In order, nosecone-to-thrust plate (L-to-R, top-to-bottom): nosecone on playa, nose section in the shop, upper sustainer body (2' Sonotube), lower sustainer body (four 10" aluminum tubes and plates), fin can with 4" motor mount (rolled door skins over ply rings) and inter-stage metal lattice, upper booster (2' Sonotube and door skin transition), booster mid-body with ribs and Saturn 1B-like tubes, booster lower body (3' diameter Sonotube), 1/2" marine plywood fins, rolled Formica boat tail and 1/2" aluminum thrust plate, lower internal support structure (metal tubing), upper internal support structure (metal tubing), one of the side-ported deployment pistons.

Scary near miss and a lesson on cluster ignition

This was a full scale SAAB that flew at LDRS 17 on a central M and four I's. The I's lit and lobbed the rocket off the pad. The M then ignited when it was oriented in the wrong direction. Lesson: ground start the main motor and airstart the outboards. Oh, yeah, this is also why you have set-off distances and don't let people wander in towards the pads :eek: Thankfully, nobody was harmed. (Once again, the snaps are from Point 39 Productions - I wish that he'd release some of these old tapes on DVD.)

The ginormous Stratospheric Dreams post

At R2K's request, I went ape shit with the screen snaps. But first, some details about the rocket:

• The project concept and motors were by Mike Ward and the construction was by Chuck Sackett.
• 'Flew' after BALLS-005 on its own waiver.
• Motor was 'S' class.
• The 320 lbs of propellant was cast in PML 11.5" couplers so the diameter was just over 12".
• The steel body was the motor case and it used actual surplus Nike fins.
• The 4000+ psi steel body was shredded.

I used a small format due to the number of photos, click to expand (as usual). (snaps via Point 39 Productions)

First, some show and tell in his shop.



Assembly on-site. Ya' just gotta love a rocket that you assemble with a sledge hammer :)



Ignition! The 2nd photo is one frame after the first. The 4th shows the range of the debris field, which fills the frame.