Saturday, February 24, 2007

Thinking About Fuel

When considering fuels and engines, the adventurer think about finding a fuel that can be produced using materials obtained 'locally', or building an engine that may support several types of fuel.
For example, here on Earth, the safest and simplest engine would be some type of hybrid. Like a NO2/epoxy-sugar or H2O2/epoxy-sugar/aluminum powder. On Earth these materials are easy to obtain, and have a modest price. They also make for an engine that is easy to throttle and control. However, if traveling to other places, the fuel could rather difficult to obtain/manufacture.
A system for a more complex engine could be a dual fuel one, that uses hydrogen/oxygen or methane/oxygen. These fuels can be obtained or manufactured on most bodies in the solar system.
Production will require a power source. Hydrogen is the most plentiful element around, all of the gaseous bodies contain significant amounts of it. It can also be found in ice, on many solid bodies and in comets. Oxygen is also very plentiful, though it takes significant energy to free it. It is available in H2O and almost all the solid bodies contain it in oxidized minerals.

It could be exceptionally difficult to design and build an engine that could work with fuels that could be produced anywhere. Different locations offer different source materials for fuel production so, it the beginning it may be better to just design an engine around fuels that can be produced at target destinations and way points. Leaving with sufficient fuel to make round trips would be excessively expensive and require a craft of excessive size, thus enhancing the complexity of the operation and increasing the chance of failure.

Tuesday, February 20, 2007

Specific Impulse

I have created a spreadsheet that will be updated somewhat regularly to show the specific impulses of various fuel combinations.
I've just started but, I currently think that propellants need to be organized along several lines, solid/liquid, hybrid, mono/bi/tri-propellants.
Another consideration is production. If you are scooting around the solar system, you're not going to find a filling station so, some attention will need to be applied to the concept of producing fuel from whatever sources are available.
This will go in the field chemistry guide.

First Post

I am starting this blog as a 'live' notebook. The idea is to collect the information in numerous notebooks scattered around and condense it into one place. At some point, this blog will go away and I'll replace it with a wiki. Until then...
Since this is rocket science, we'll see some chemistry, physics and math. However, most of the chemistry will be stoichiometry so, if you took it in high school you'll be able to follow along. The physics shouldn't be too much of a reach. I'll try to keep the math to a level where anyone can do it.
In the beginning, most of the math will cover things like calculating escape velocity, specific thrust, energy in chemical reactions, and (really) basic orbital mechanics.