Simplest and cheapest rocket possible

[nutball]

Well it's often said that a rocket is basically a controlled explosion. Most of the suggestions in this thread seem to be in the

Controlled [-------------------|------------------X] Explosion

regime.

 

[Blazkowicz]

What would be the simplest and cheapest rocket possible, that you could build yourself from stuff that is readily available and be capable of lifting stuff into orbit? Adding as much of them as it takes to lift the mass required (in stages if needed) is no problem, as long as they're really cheap.

Alternatively, if scaling them up is easy, a reusable SSTO is of course nicer.

My thoughts:

1. Solid fuel rockets are very simple and cheap, great for the small stuff, but hard to scale. If you go beyond firework scale, they become quite hard to build, the thrust can vary a lot and they're almost impossible to throttle.

2. Liquid fuel scales great, but requires a lot of practice, effort and a well stocked machining shop. Unless you can come up with something really basic and (almost) solid-state, the amount of flaws possible will make the rate of error very high (comparable to the amount of components), and the initial investment quite big.

3. A single engine always has a better weight/thrust ratio than multiple engines. It's only the weight of the fuel tanks and supporting structures that makes multi-stage rockets perform better. But they also suffer from diminishing returns: you do need to lift more.

In short, I think the simplest and cheapest design is probably best. Saving weight can always be done later, if needed (and affordable).

If it can be done really cheap, I really want to try and build one.


Or how about a Beyond3D X-prize entry?

you're probably a terrorist