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Adrian,

Just curious--are you using EAGLE as your layout editor? I spent a good portion of my summer developing some board prototypes with that and thought I recognized the layout style...

Quick model I did in Rocksim, aero analysis done in RASAero (based on that, used a Cd override of 0.26 in the Rocksim simulation--the flight only gets up to ~0.8 Mach, so the constant Cd assumption...

Another question to be asked is whether the 24.5 oz mass spec you're using is from Rocksim directly, or if this is the measured weight of your finished rocket. The adhesives, paint, and occasional...

http://abcnews.go.com/GMA/video/seals-worlds-1st-stealth-helicopter-13533840

This sounds promising...

In general, the radius is going to be the length of the "arm" you'd use to trace out the nose shape. For a 4" nosecone with a length of 16.5" you would want to use an arm length of 69.06 inches. ...

Based on the specs that Semroc gives, BT-30 has a slightly larger I.D. and a slightly thicker (0.021" vs. 0.013") wall thickness.

BT-20 has an O.D. of 0.736", and an I.D. of 0.710"
BT-30 has an...

I'll be there competing.

It's actually a new kit, the Astron--it follows the same basic design as the Astro-1/Astro-Jr, but being based on ST-8 tubing with an 18mm motor mount, fills a gap between the 13mm ST-8-based...

As for this, polished is probably as close as anything. I wouldn't worry about it too much; the finish is probably used to some very small degree in calculating the drag coefficient, but really, the...

Much of my decision-making process on fin thickness (and probably true for many/most others) is just experience with what works and what does. For very small rockets (13mm motors or lighter-weight...

If you've got a clear view of the horizon in the East-Southeast direction just before sunrise (~4:30-5:30 am) on the morning on June 8th, you should easily be able to see Jupiter, which will be (with...

I was just about to say that if nobody else had.

The G64 launch photo looks interesting... All of the G64's I've seen have had a well-defined flame and very white smoke. In this case the flame is partially obscured by smoke and the exhaust plume...

Boosted darts?

Again, it isn't a practical design safety-wise... the mass of the upper stage has been optimized and sized based on it being a solid stick of tungsten. According to RockSim, if it...

It might not even be all that close, but this should tide you over until Cesaroni releases it in an official update. I based the performance off of the thrust curve shape of the only other 98mm 3G...

Apogee Components used to sell 10.5mm tubes for their specialized motors back in the day, and they might still sell that tubing, but I know that Semroc now sells BT-4, which has an I.D. of 10.7mm.
...

Try this for nose cone shapes

1- best
2- good
3- fair
4- poor

From: http://en.wikipedia.org/wiki/Nose_cone_design
http://upload.wikimedia.org/wikipedia/en/a/a1/Nose_cone_drag_comparison.png

Apologies; I don't frequent that site very often so this was the first I'd seen of it.

Just happened upon this video today:
Pro98 6G N10,000 Vmax

UVaPMWLKOWQ

Hmmm.

This article and diagram might be of some use:

http://en.wikipedia.org/wiki/Nose_cone_design
http://en.wikipedia.org/wiki/File:Nose_cone_drag_comparison.png

You won't be able to break mach...

Great motors, I've flown 4 of them on two different flights, clustering 2 E20-7's with 2 D10-7's. Based on a test flight of a single D10 that had trouble lighting, my first cluster flight used a...

A rather unhappy 6-day stretch for the U.S. space program

January 27, 1967 -- Apollo 1
January 28, 1986 -- STS-51-L, Challenger
February 1, 2003 -- STS-107, Columbia

IT'S A...

Based on the white caps and the ~1.6 second burn time from the thrust curves, looks to be 33 D12's.

Edit: Oh, the video says 32. I thought I had counted 6+6+7+7+7 motors.

Casio EX-FH20

Let the high speed videos begin!

A preview; just a bit of what I've done so far (this is a trebuchet I designed for a physics class competition this past May)

-Nt-U1NE954

There's a short section on gap staging in this article, with more links towards the bottom:

http://www.apogeerockets.com/education/how_to_multi-stage.asp

http://mac.softpedia.com/get/Math-Scientific/OpenRocket.shtml

It is possible, it just isn't quite as reliable as black powder piston launching. Black powder motors are essentially "instant on," and once they light they tend to come up to pressure without...

I had a 60 day trial of Norton when I first got my laptop, and it seemed to do its job well. I've used BitDefender in the past, and though it also seems to do well, it can, at times, hog up a lot of...