Cheap open source orbital capable rocket

[Brethern]

And rcandy is not one of them.

You can put radiologically dangerous stuff as the payload. You can put viruses inside. You don't need to put anything, and it will still wreck havoc with the world. It might trigger a war.

Any credibility you had with any statement in this thread just went out the window with this post.

I have the injuries and I can also provide video evidence proving exactly why R candy is not something to be taken lightly.

[lajoswinkler]

It precisely is one of them. When I grabbed an example out of the air, I was thinking of actual injuries rather than imagined ones. And I happen to detest government bans on homemade rockets/rocket fuels.

Please don't be offended when I remind people to be careful with a dangerous procedure. You are free to be reckless with your own safety if you wish. (Provided you do so far away from me.)

Other than sticking a pile of it on or in your body and lighting it on fire, I don't really see the danger. It's a very stable, plastic mass which burns relatively slowly and won't detonate. Nothing like gunpowder, which detonates under pressure.

I've burned my skin a few times with it, but that's it.

Unless you're talking about incorrect ways to make it (melting the contents) which causes hotpockets and stove inferno, I don't really see the danger.

I've never ever heard of someone losing their fingers over rcandy, and I was totally into rocketry.

Any credibility you had with any statement in this thread just went out the window with this post.

I have the injuries and I can also provide video evidence proving exactly why R candy is not something to be taken lightly.

Please provide the evidence and tell me what exactly you did with this material that would cause a loss of limbs. I've worked my ass off with rcandy formulations and I've never ever experienced anything that could violently detach a body part. Yes, you can get third degree burns and subsequent necrosis, but we're talking about blowing your fingers off.

I never took that material lightly. All I'm saying is that I can't see how someone can unintentionally detonate it and lose body parts.

A rocket with 1kg payload is not even going to make a blip on any early warning system. You're more likely to get in trouble with your local aviation authority than any government.

In a long run, if these things do become affordable enough for some shady people to start making them, yeah, I'm sure they'll get more sensitive equipment and require formal approval for launch. But since that's not going to happen without some major revolution in propulsion technology, it's an academic point.

So you just went from a ~9km/s requirement down to ~8km/s. That's not something an upper stage can manage. You still need most of your rocket, as well as one hell of a balloon.

You're not listening. I'm not talking about a "big rocket". I'm talking about a missile that has achieved sufficient altitude and speed, and is heading towards a city on another continent.

Anything unidentified flying that fast, that high and on that trajectory will cause panic. The missile would be under attack, emergency president lines would ring like mad. People monitoring these things don't know what's flying up there. All they know is that the data looks like ICBM. That's enough. It's a DEFCON 1 scenario.

If an amateur in Australia would launch something like that towards North Korea, hell would break loose.

Anyway, it's not going to happen. Vehicles capable of achieving orbits are not something anyone can build at home. The money involved is insane.

[Aghanim]

Well, that its why you need to notify the officials before launching..

Now, here is the thing. Is rocket built by amateurs are capable of reaching orbit? Hybrid rockets are capable of reaching required Isp that my OP rocket calculation. However, getting the oxidizer is the hard thing. LOx needs relatively significant infrastructure to make, but the feedstock is ordinary air. Hydrogen peroxide is liquid at room temp, but HTP is a nasty stuff. Nitrous oxide seems to be the most easiest to get and its safe.

Fuel is the easy part. Paraffin or rubber based fuel could do the trick in hybrids, kerosene looks good in biprop rocket

Let's retry, now we are plugging 30g payload to the rocket equation:

Payload is 30g, rocket is 5kg, Isp, assuming paraffin with aluminium powder and nitrous oxide as propellant gets us 200 Isp, each stage at 3000 m/s dV

3 stage probably cuts it

Upper stage: 23 kg

Middle stage: 106 kg

Lower stage: 489 kg

[Aethon]

So you just went from a ~9km/s requirement down to ~8km/s. That's not something an upper stage can manage. You still need most of your rocket, as well as one hell of a balloon.

That's what she said..

Sheesh. You save a guy what he admits is 1000km/s ( and I would say a well engineered multi-stage balloon launch saves more than that ), to LOE which is half way to anywhere, and get nothin'. Rough crowd,... no esteem.. no regard. :^)

[christok]

I do believe we are overlooking a legal problem. There are often limits on amateur rocket sizes. (42 kNs total thrust in the US IIRC.)

Now that could be a problem.

[Armchair Rocket Scientist]

And... there's where you get it wrong. 1 cubesat weighs at 1 kg

There are also 2U and 3U cubesats, with masses of 2 and 3 kg respectively. A 10 kg payload allows for the simultaneous launch of several cubesats.

Assuming fuel tank and rocket engine at 20 kg, structural bracings at 1 kg for lower stages, payload at 1 kg

Which is a horrible assumption. Here's why:

We want orbit injector to be at 3000 dV, so plugging that into the rocket equation:

Dry mass= 1+20 = 21 kg

dV = 3000 m/s

Isp = 270 s

Wet mass = 65 kg

In other words, the stage's wet/dry mass ratio is 3.2. By contrast, this rocket, the only amateur rocket to reach space I know of, has a mass ratio of 2.5.

Intermediate stage:

Dry mass = 65 + 20 + 1 = 86 kg

dV = 2500 m/s

Isp = 230 s

Wet mass = 245 kg

Mass ratio: (245-65)/21 = 8.57. On the other hand, a Space Shuttle SRB has a mass ratio of 6.48.

Launcher stage 2 :

Dry mass = 245 + 20 + 2 = 267 kg

dV = 2500 m/s

Isp = 230 s

Wet mass = 809 kg

Mass ratio: (809-245)/22 = 25.64. This is comparable to the Falcon Heavy boosters at a mass ratio of 30, which is the highest I've heard of.

Launcher stage 1 :

Dry mass = 809 + 20 + 3 = 832 kg

dV = 2500 m/s

Isp = 230 s

Wet mass = 2522 kg! I'm starting to think that this project isn't feasible...

Mass ratio = (2522-809)/23 = 74.5. This is WAY better than any rocket every built.

Based on the stats of the real-life Scout launch vehicle, a mass ratio of 7-8 is probably the limit for a solid-fueled stage at the scale we're looking at. However, amateurs wouldn't have access to fancy materials or machining techniques like graphite-epoxy casings, isogrid structures, aluminum-lithium alloys, etc, so I cut that in half for a mass ratio of 4:1.

My half-arsed estimate is that if you were extremely lucky, a rocket like this could be designed and built for a few million dollars. This assumes that all the engineers involved are working on the project on their own time, but the team would probably have to hire one or more lawyers to deal with the legal issues surrounding the fact that you're building a device that could deliver a small nuclear weapon to most of the planet within an hour.

[Brethern]

Other than sticking a pile of it on or in your body and lighting it on fire, I don't really see the danger. It's a very stable, plastic mass which burns relatively slowly and won't detonate. Nothing like gunpowder, which detonates under pressure.

I've burned my skin a few times with it, but that's it.

Unless you're talking about incorrect ways to make it (melting the contents) which causes hotpockets and stove inferno, I don't really see the danger.

I've never ever heard of someone losing their fingers over rcandy, and I was totally into rocketry.

Please provide the evidence and tell me what exactly you did with this material that would cause a loss of limbs. I've worked my ass off with rcandy formulations and I've never ever experienced anything that could violently detach a body part. Yes, you can get third degree burns and subsequent necrosis, but we're talking about blowing your fingers off.

I never took that material lightly. All I'm saying is that I can't see how someone can unintentionally detonate it and lose body parts.

I was talking about incorrect ways of making it. And it can blow fingers off if you mess up. I've had mixtures explode on me before.

[SlimeCrusher]

Why orbital capable? I would preffer a sub-orbital flight alot, you can attach a camera and a home-made parachute with some fancy remote controlled thing to deploy it, you launch the rocket as high as you can, and then you can see it burning on the atmosphere, or even better see it come back and land!

Now, an orbital flight is just dreaming too much, the deltaV requirements are too high for a single stage rocket, and even if you could make an SSTO, you would never get to see the probe again so yea

[K^2]

You're not listening. I'm not talking about a "big rocket". I'm talking about a missile that has achieved sufficient altitude and speed, and is heading towards a city on another continent.

Anything unidentified flying that fast, that high and on that trajectory will cause panic. The missile would be under attack, emergency president lines would ring like mad. People monitoring these things don't know what's flying up there. All they know is that the data looks like ICBM. That's enough. It's a DEFCON 1 scenario.

You're not listening. They wouldn't even know that rocket is there. Equipment isn't designed to register launches of anything that small. If it was, the IR satellites would raise an alarm over a fireworks display, and the orbital tracking would be constantly reporting threats from meteorites on collision course. They simply aren't looking for anything that small.

[Armchair Rocket Scientist]

Why orbital capable? I would preffer a sub-orbital flight alot, you can attach a camera and a home-made parachute with some fancy remote controlled thing to deploy it, you launch the rocket as high as you can, and then you can see it burning on the atmosphere, or even better see it come back and land!

Now, an orbital flight is just dreaming too much, the deltaV requirements are too high for a single stage rocket, and even if you could make an SSTO, you would never get to see the probe again so yea

Well, there's not really a need to make a thread on whether tha's possible:

[Seret]

K^2 is right in that there's no way in hell they'd detect a 1kg warhead coming in.

Depending on the range you're taking about they might detect it during boost. The exact technical capabilities of the ICBM tracking forces are of course a closely guarded secret, but it's not unreasonable to think that they'd have trouble handling things a lot smaller than they were designed to detect. Even if they did spot the thermal signature of the launch it seems likely they'd be unable to predict the trajectory with their enough accuracy to cause alarm.

The Hollywood trope of the twitchy finger over the nuclear button has proven to be inaccurate in reality. On at least one occasion in the Cold the Russian early warning system held fire when they thought they had a US missile inbound because a single missile was considered anomalous.