17 replies to this topic

[paul]

Hello everybody!

As I read through nakka-rocketry.net I came across this link: http://sugarshot.org/ .

What can I say. I find this project very interesting. As we saw, men can reach space without spending billions of dollars into research but only a few millions. So this experiment would be the first time, that a "model rocket" could reach space. The specifications for that rocket are in quite a small range though.

I wonder what you think about it! I am not sure if you can reach space with a Sugar/KNO3 based rocket.


with best regards,

paul

[Andrew]

Is this organisation based in the UK? does anyone know?

There is unfortunate leglislation that would prevent any such project in the UK. A long time ago it was decided that no rocket development of any reasonable scale will happen in the UK. It would be good if we could do something like this here.

I am currently woking on a project called SSETI. It is a project funded by the ESA so we do not have to worry about the money side. I am working on a spaceship that is going to the moon, thats 483000km ish above the earths surface, a little more complicated than 100km. One hopes that we will be able to get a 5cm narrow field telescope there, We should be able to resolve footprints on the ground from the LMO we want to put the spaccraft in.

Edited by Andrew, 11 December 2005 - 05:43 PM.

[Chaz]

Best of luck to them, but I find it very hard to believe they'll manage it. The escape velocity of Earths gravitational pull is 11km/s, I'd like to see a sugar rocket travel that fast.

[fishy1]

i suspect they won't just be using standard sugar/kno3, they'll have lactose i think? or some other kind of sugar, but not normal sugar i think, something to do with hydroscopicity. i thought it had been done already?

[Richard H]

The rocket won't need to be doing 11km/sec because it is not travelling to outer space. Once it passes the internationally recognised boundary of 62 miles it will return to earth.

[Andrew]

The rocket won't need to be doing 11km/sec because it is not travelling to outer space. Once it passes the internationally recognised boundary of 62 miles it will return to earth.

Yes, from first glance, the site says they are trying to just reach "space", hypothetically you could reach it travelling at any velocity (even 0.001ms-1), and then fall . I personally would not want to try orbital flight that high, you would not last very long. Even up at 300km where the space shuttle and ISS fly, you can see them glowing from earth because of the drag caused by particles hitting it. A small satellite like Pico Sat (another one I am doing some work for) that weighs about 1kg, only lasts about two years before burning up, right up at 700km. LEO flight is a real dangerous hobby to play with, especially if you want to be on a 98 degree inclination.

[Rhodri]

Hi....so are we saying here that this projectile will need to come back to earth and there is no *simple* way of predicting where?

Edited by Rhodri, 12 December 2005 - 07:49 PM.

[mnementh]

Hi guys,
The term "Sugar shot to space" might be a bit constricting for most, as sugars are pretty much well defined and have proved problematic as a rocket fuel, mainly due to decomposition while melting to produce a cast "grain".

However, Richard Nakka's fuel of choice, until very recently, is an alcohol derivitive of sugar, called Sorbitol. This compound melts well below it's decomposition temperature and mixed with KNO3, can be poured into a rocket case. It is a very safe and very efficient propellant.

Sorbitol is incredibly common but damn nearly impossible to obtain, outside industry. It's used in virtually every toothpaste, chewing gum and anything else that uses the word "cool" in it's title. (cool here, refers to temperature, by the way, not street cred.).

As to recovery, it's pretty certain that this rocket will have some kind of guidance system, coupled with electronic recovery and location telemetry.

Sandy

Edited by mnementh, 12 December 2005 - 08:11 PM.

[paul]

Sorbitol is incredibly common but damn nearly impossible to obtain, outside industry. It's used in virtually every toothpaste, chewing gum and anything else that uses the word "cool" in it's title. (cool here, refers to temperature, by the way, not street cred.).

?! You can get it in the super market. 1.3€ IIRC for 500g. Have still some left @ home. I do my smoke devices with it (lower melting point = safer)

Its sold as a sugar substitute for dibetics.

Edited by paul, 13 December 2005 - 09:32 PM.

[sizzle]

Its sold as a sugar substitute for dibetics.

It's diAbetics

[paul]

I would call it typing error

[Andrew]

On a simple/safe rocket engine note, SSO, the space craft that won the X prize, used a rubber cylinder with a hole down the middle and they sprayed hot liquid oxidiser into it. How simple is that!!

On a landing note, I'm pretty sure they would be some form of ADCS and/or "guidance"/"feedback tracking" on board.

[RegimentalPyro]

The Black Knight rocket which was produced by the British Space Program [yes - we used to have one!] in the 50's and 60's used an even simpler system I believe.

They took Hydrogen Peroxide [H2O2] and passed it over a silver screen. This caused it to decompose into Hydrogen and Oxygen which they promptly lit. the system was gravity fed [ie: H2O2 in a tank at the top of the rocket] which kept things nice and simple.

[Andrew]

Peroxides decompose to water and oxygen. An additional fuel would be required, it would have probably have been a short chain alcohol.

In some of the small satellites that SSTL has made they used butane as a fuel for thrusters (purely using the expansion of the liquid to gas), but some of the larger ones use butane and peroxide combustion thrusters. A common (simple) rocket fuel is ethanol; as used in the V2. It is liquid at stp and has a low vapour pressure. It, unlike H2 or hydrazine, does not need pressurised or refrigerated storage.

[Mumbles]

The H2O2 motor works by the heat and pressure of the H2O2 decomposing. Both of you are correct. It is a monopropellant, but it does go to water and oxygen. I however see no reason why you couldn't inject a flamable fuel in with the products to produce even more thrust.

I'm sure there is more than one type of rocket that uses H2O2 as a propellant, or part of the propellant. I have heard of H2O2 and liquid methane I think it was.