I want to build a solid fuelled rocket (I was thinking 3 stage with 2 boosters) that'd launch a micro-satellite (cubesat size) into space but first I want to try reach space (100km) with no payload. NASA shows the % composition for the fuel they use in their solid fuelled boosters.http://www.nasa.gov/returntoflight/system/system_SRB.html I think I could use this but use a different binder I've done some looking around and I've found 2 'small' rockets that have reached spaceand the GoFast rocket. Judging from this I think my rocket could be around 10-X meters in length and internal radius around 0,3-0,X meters. On Alibaba Ammonium perchlorate was $1-5 per Kg and that is 70% of the fuel mixture. Also from what I understand I just need to reach 11km/s and then even if the rocket Cuts out it'll still enter space as escape velocity has been achieved.
First, I suggest watching this tv show:
They set out to put a backyard rocket into space (note: space, not orbit.) Unfortunately, that turned out not to be feasible, they ended up settling for sending a hybrid rocket up about 10 miles and with a lot of assistance. The problems that come to mind:
- So far high power solid hobby rocketry is a field that has self-regulated. If you want anything to do with the current practitioners you have to work within their format--and that requires working your way up in size.
- FAA permission. They're not going to be one bit happy with you if you launch something like that without clearance. Since your bird isn't meaningfully controlled they have to clear the whole airspace your bird could reach. For high-flying birds you need a remote location far from any airways so clearing it isn't too disruptive.
- Safety zone. The usual standard here is 1/4 the max height. You want to put a rocket over the Karman line, that means a safety zone of more than 13 miles in every direction from the point of liftoff. Got access to that much land??
- Note that the safety zone is impossible for the big birds so it's handled differently: There's somebody watching the flight path of the rocket, if it goes too far off course they push the big red button and the rocket turns into a bunch of little bits. (For a recent example, the SpaceX CRS-7 mission. In that case the flight control computer suicided the rocket when it started coming apart.) Those flight termination systems are made of explosives--and that means an explosives license.
- Note that even the rocket fuel is considered hazardous material and in those quantities subject to some fairly onerous storage requirements. You'll have to do all your work on a pretty darn big piece of land to make the regulators happy. Handle it wrong:
Since you added that drawing I am adding this answer to specifically address your drawing:
No. It will not reach space.
Note that there is nowhere near enough information in your drawing to reach this conclusion, I am saying that anyone displaying the level of ignorance of the subject that you have has zero chance of reaching space no matter what the rocket.
You seem to be showing two strap-ons of approx 300mm x 10m and a central booster of 300mm x 13m. The nose cone length isn't really relevant here. However, there is nothing to indicate the thickness of the wall. You also need to know the weight of the whole thing as well as the specific impulse of whatever you are using as fuel. Likewise, there's nothing to indicate the thrust of the rocket. (The higher the thrust the less gravity loss there will be but the more drag loss. Also, the higher the thrust the thicker the walls must be and thus the heavier the rocket.)
I note no means of steering this rocket. When you light this it's not going to straight up. A simple test to demonstrate what your rocket is going to do: Take a normal hobby rocket motor, make a nose cone for it out of paper and glue it to the engine. Make a little cardboard stand to hold it upright. Take this out into empty desert terrain (what I am describing is a major fire hazard, you need to ensure there's nothing around that can possibly burn) and bring along a few hundred feet of two-strand electric wire that has alligator clips on the ends. Insert the igniter, clip the leads to it and back off the length of the wire. A normal automotive battery should be able to provide the firing current through a wire of that length.
There were some tests out of China Lake in the late 1950s to see if small multi-stage solid fuel rockets could reach orbit. Results were inconclusive because they didn't have the telemetry and radar systems to detect success or failure. These rockets were launched from high altitude jet aircraft. There have been a few hobbyist attempts at repeating this effort the same air-launched style, none reaching the point of significant testing as far as I know. Most recently, there's CubeCab, which proposes multi-stage solids launched from a fighter jet that can reach high altitudes. www.cubecab.com. By launching from F-104s, which can fly both high and fast, you get a kind of reusable first stage that could make it possible to launch something as small as they hope to make all the way to orbit.