Order of Kilopi
I thought about putting this under 'Space Exploration', but I refrained before the possibility of getting virtually lynched.
Mr. Widget wants to go to space. Ken Schellenberg, who has adopted the alter-ego on his company website, wants to put a simple but highly engineered bottle rocket into orbit.
Administrator
From the link
I'd say he has a ways to go, but everyone needs a dream. I wish him luck.Several years ago, one of his "toy" rockets - actually a Kevlar-reinforced, experimental, single-stage missile pressurized with compressed nitrogen and packing high-tech instruments - flew to just under 379 metres.
Based on that research, Schellenberg is now convinced that it will be possible to put a bottle rocket into orbit. In preparation, he's working on sending a modified two-stage rocket - reinforced with ultra-strong carbon-fibre and fuelled by liquid CO2 - up about five kilometres
And Argos, I think it would have been a hoot to put it in Space Exploration.
Order of Kilopi
When I heard bottle rocket, I was thinking a rocket that you normally stick in the neck of a bottle to launch it.
A rocket made from a pop bottle never entered my mind. We always used those little red and white pump jobs.
I'd like to see somebody figure out the math on what it would take.
Order of Kilopi
I'd like to see somebody figure out the math on what it would take.
In the mean time, I'll take bets on how long it takes one of you to work this out. I think my money's on 5 minutes...
Established Member
Wow, 379 m. The best my kids and I managed with a single stage 2 litre rocket was 67 m. That was pressurized to 110 psi using 600 ml of water.
I told my kids that while it may be fun to launch these toys, the "real" ones had to have a payload. What could be a payload for a bottle rocket? Why, plastic men with parachutes! So everytime we launched, there would be a hoard of kids chasing after these parachute characters.
I thought about another possible purpose for these rockets and realized that if the mechanism for opening the parachute could be rigged to set off a camera shutter, then I could get true (albeit random) bird's eye views of our little town. If you think about it, aircraft aren't allowed to fly so low over settlements unless on takeoff or landing, at least in this country, so it's a bona fide application. But I lost patience with it before it was perfected. However, a number of other big kids have managed to get their water rockets to work as aerial photography platforms.
Order of Kilopi
Times up...where's my cash?Originally Posted by Fazor
In the mean time, I'll take bets on how long it takes one of you to work this out. I think my money's on 5 minutes...
Order of Kilopi
I'll put the nickel in the mail, but you have to send me a stamp first.
Order of Kilopi
Reminds me of the OTRAG company some 30 years
ago developing a nitrogen pressurised module
forcing fuel to the nozzel with car windscreen
wiper motors as cheap actuators. A few dozen
units made a small space launcher. I was
rooting for them but some quarters did not
like the places the company operated from.
One or two test firings I remember.
Order of Kilopi
IIRC, OTRAG was being funded by Libya. There was a great deal of doubt about Libya's desire for a peaceful space exploration capability.
Banned
Reminds me of the highest I ever launched an Estes rocket - about a mile.
Heavily modified rocket, and engine scheme, though...
Order of Kilopi
And Estes used to sell (still does?) the Camroc, a cheap plastic single exposure nosecone--the rocket engines were timed so that the release charge didn't blow until the rocket had turned and was zooming back earthward! That triggered the shutter.
Order of Kilopi
they sell them with digital cameras in the nosecone now. the one i was looking at in WalMart (of all places) last week actually made an mpeg movie looking back towards the ground from launch until it hits the ground again.
Order of Kilopi
How did you get it to a mile?
I've got a personal altitude record of 11,950, but that had nothing to do with estes type stuff (with which my personal record stands at about 3000 feet with estes motors, 5000 feet with an estes rocket but decidedly non-estes motors.)
Order of Kilopi
Well, the numbers escape me even though I've read them a bajillion times (signs of age?), but escape velocity is known, so there isn't really any need for hope or dreams - - just the right velocity.
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Yes; I have an idea there, I'm speaking in relation to the launch vehicle.
Propellent and compressible gas weight and volume.
Pressures needed.
That stuff.
Banned
Rockets are cool
http://www.sciencevideos.com/images/golftube2.jpg
Order of Kilopi
True dat!Rockets are cool
Member
I was playing with dry ice and plastic soda bottles once. Making dry ice bombs. I ran out of plastic bottles and had a small glass coke bottle left. I put some ice and water in it then put the top on and quickly tossed it. It landed in dirt bottle top down, made a thudding boom and vanished right in front of my eyes. I looked around and for it and spotted it at about 100 yards altitude and ascending. It continued for another 50 yards up nosing over to 100 yards down range when I lost sight of it. It left a five inch hole in the ground. The bottle top and the neck of the bottle were in the hole.
Banned
It must be funny...
Banned
I stuck an Estes D engine into a rocket designed for an A engine, shaved the fins very fine, didn't use the parachute, modified the nose cone, hallowing it out, etc. I did the telemetry with a friend standing one mile away with an inclinometer, and me (at the launching pad) monitoring the trajectory.
Simple trig, and yes, it bested a mile by several hundred feet. Twenty years later, I reached 50,023 feet, my highest, but that was in the military. Another story.
Established Member
Back to the bottle rocket.
Big is better, so I tried an office water dispenser bottle - 25 liters or so, inflated from a compressor and airline to about 30psi (the seals started leaking). The result was very disappointing!
The downloadable water rocket simulator (see: http://ourworld.compuserve.com/homep...se/h2orckt.htm) confirms that this size just doesn't work.
Why?
John
PS I was looking for horizontal thrust, rather than lift, but it was still no good at all.
Banned
Hollowed out the nose cone, chose to monokote the rocket and fins instead of painting them, modified the fins, and stacked three of the biggest (most total impulse) D-series engines in the fuselage which was originally designed with an adapter ring to hold an A/B/C sized engine. I think it was around 20 newton-seconds of impulse. The first two had a slight delay to allow for a bit of coast time before firing the next stage (and blowing out the spent engine). The last one had the longest delay - six seconds (if I recall correctly).
Naturally, the rocket didn't survive very well... Lots of burns and lost a couple of fins.
Order of Kilopi
Was it with this, or with several D motors as stated a couple posts below this? One D motor sounds pretty much impossible, seeing as the current national D altitude record stands at 1214m, well under a mile. With staged D motors done properly, it would be possible, though still an impressive feat (more so if you got accurate tracking on it to determine the altitude).
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