Space Program-098

>>7761542
There are model rockets that use small SRBs. Good luck obtaining rocket fuel and building engines. You basically need to be Elon Musk

>>7761550
I'll think about SRB's as for the rocket fuel i found a place where they sell the stuff....anyways the problem isn't the fuel or engines problem is trying to get it past earth's gravitational pull i don't know what material is best for the construction of the rocket...

>>7761553
Rocket fuel isn't that hard, even plain kerosene will work. Oxidizer is the fun part though.

SRB-based amateur rocketry is closely related to firework making, and these can reach pretty good altitudes. You'll find a plenty of recipes for powder-based rockets using saltpeter as oxidizer and various fuels like charcoal, aluminium oxide, sulfur, and many others. It's a pretty common hobby.

Now if you want liquid-fuel rockets, things get more tricky. Best if you could get access to a cryocooler that can produce liquid oxygen, but these are NOT common. Another approach is welding oxygen, you can even use acetylene as the fuel, using the standard welding setup as your fuel source. And if your fuel and oxidizer are pressurized, your problem with turbopumps or pressurizer gas vanishes. Just a common bell nozzle (should be doable with a common lathe), injectors (just tiny "sprinkler" nozzles), ignitor (spark plug, or even a piece of fuse), and you're fine. Getting the proportions between oxidizer and fuel would be a lot of work, and you will not get your rocket very far because your combustion chamber will soon overheat, but a couple hundred meter, even a couple kilometers should be well within reason.

And don't worry about the combustion chamber shape too much. Straight cone gets some 80% efficiency of the "optimal" bell shape, so even roughly right will still get you good 95% efficiency of "real" rockets. What you need to worry about is getting the mix right, using fireproof materials (the combustion chamber will run REALLY hot without cryofuels for cooling), and safety.

>>7761542
Who said you need a rocket? Helium balloon will get you close enough to space.

Also, if you want to look into home production of oxygen, look into Zeolite. Pressurize air to 1.4 bar in a chamber mostly filled with zeolite, and it rapidly begins adsorbing nitrogen, leaving you with about 85% pure oxygen. Then release (and collect) the oxygen, then vent the remaining nitrogen and start pressurizing anew. Synthetic zeolite may be hard to come by, but you can obtain natural zeolite as a kind of specialist flower soil, costs peanuts and has about 50% adsorption capacity of synthetic zeolites (meaning you need double the volume, but as I said, it's cheap.) It's used in medical oxygen producing devices, but these cost premium ("medical applications"), still, the devices are simple enough that you should be able to cobble one together yourself.

>>7761542
>i fear humanity will collapse soon and the only option is to leave Earth and somehow lock in Earth's orbit
Lmao and how are you going to sustain yourself up there

>>7761610
Space juice

>>7761598
Thanks for the advise!I'll look into it,liquid fuel rockets are tricky but i think i can manage,and one more thing...you can use kerosene as rocket fuel??

>>7761610
Actually that's a good point....hmm

>>7761613

German V2 used kerosene.
Falcon 9 uses a compound that is very close to kerosene.

As I said, *fuels* are easy (unless you go with liquid hydrogen which is a bitch to handle). It's the oxidizer that is the really difficult part. Not only must you use more of it than fuel in most cases, pure oxygen in high concentrations gets quite corrosive and makes stuff burn you would never believe could ever burn. For example, steel.

>>7761614
Just learn to live off the land and move somewhere there are no city's for at least 100 miles.

But keep in mind if the nukes fly. They target civilians not enemy bunkers.

>>7761618
Not them, but:
>It's the oxidizer that is the really difficult part.
Given it's relatively available, shouldn't liquid nitrous oxide work as a cheap rocket oxidiser?
You'd need to be a little careful with handling it, given it can explode if the vapour is badly mistreated. It's self-pressurising too.

Personally, if I were into long-term survivability, I'd look into going down, not up. Obtain an old, depleted mine. Go some two kilometers down. Get geothermal power source, enough growth lights to start an underground farm, a large well-lit reservoir for growth of cyanobacteria for oxygen production (you won't get by on plants in reasonable space), a deep underground water source, some machines/equipment for metalworking to be able to produce replacement parts yourself, and you can make a habitat that could carry a small population through several centuries. Seal the shafts leaving just outlet for pumping excess water out, and you're fine.

Living in space is a nasty business. Cosmic radiation will shit you up anywhere in open space or on surface of pretty much anything except Venus (where pressure and sulphuric acid rains will do you in). The only way to make sustainable habitats "out there" is to dig under the surface and they don't have anything a good mine won't have (well, maybe except drawing solar energy from the surface - but then you have geothermal instead).

>>7761600
but not into orbit

>>7761542
>>>/x/

>>7761632
>a large well-lit reservoir for growth of cyanobacteria for oxygen production
Why would you use geothermal heat to make electricity to power lights to grow cyanobacteria to produce oxygen?
Just crack CO2 directly via chemical or electrical means.

>>7761629

If you read the Wikipedia article, it's an okay oxidizer, safe, stable and easy to handle. It doesn't have much oxygen in it though, and not very impressive energy of own decomposition, meaning you won't be getting any awesome energy levels out of it.

Admittedly, I've never looked into it and honestly I have no clue how much good it is. Though if it's used in hybrid rockets, then it's certainly worth attention. They are very promising design, combining most advantages of SRBs and LF engines, and few of their disadvantages.

Certainly makes sense for amateur rocketry, though I'd personally look into stuff with more oxygen to it.

>>7761642
...if we develop a 100% safe method.

The problem is the reaction doesn't go CO2 -> O2 + C. It goes 2 CO2 -> O2 + 2 CO.

Whatcha gonna do with all that carbon monoxide? And how do you make sure it doesn't leak to the oxygen side?

I've been doing calculations for that on Mars, using Mars atmospheric CO2, and cyanobacteria beat it by far because of need of pressurization, which takes a plenty of energy. Not a problem on Earth, so yeah, energetically it's superior. But that carbon monoxide really messes up the logistics of using it in closed circulation systems.

>>7761648
Not to mention that CO2 is a very stable molecule so all the effort won't be worth it and doing it eitherway would be dangerous because of what you said.

>>7761657
Cyanobacteria method is pretty safe, though of course not very energy efficient. Electrolysis of CO2 with Zircon catalyst is actually surprisingly energy-efficient, but as I was reading a paper on it, they detected CO leak on the oxygen side in one of their catalysts. Plus only about 30% of CO2 passing through the zircon filter is separated, so it's not really sustainable - not a method for a closed circuit system. Really, the artificial method looks great on paper but once you get into the details it gets pretty messy.

Probably, unless the "outside" really fucks the atmosphere up, a reasonable way would be to draw air from outside and filter it well. Strip CO2 and dump it back into atmosphere, concentrate oxygen with the zeolite method, dump the oxygen-depleted air, filter the oxygen well and inject into the habitat - then elsewhere capture the CO2 and dump it outside.

BTW, as I said "energy-efficient" and that I calculated it - 152W providing 380cc of oxygen per minute, which is the standard usage for one human. The numbers are pretty nice but you need about 2500cc of CO2 intake to maintain that output, discarding some 2120cc of CO2-CO mix.