A Harrier's RCS System
Every crazed fan of anything will of course try to recreate his chosen fantasy. So something i've had on my mind for a while now is: howto create a real Lander. For starters i'd settle for a Radio Controlled working/flyable scale model, since it's a little more down to earth. For those interested, no, no i don't have any RC model-plane building experience. I have been looking around the internet for anything similar to this but have had absolutely no luck.
Because of the complexitys of the guts inside this thing, i'm thinking the body will have to be have to be in the range of 2 feet wide/long. Made of aluminium. yes metal.
Not sure.
In a perfect situation, a traditional liquid fueled combustion rocket would be great, but i don't think anything like that is really accessable, even to RC model builders.
Traditional hobby rockets that use solid fuel only last a few seconds at most and then they are outof fuel, i don't want a lander that only flies a few seconds, so that's outof the question - even though the power of solid fuel rockets is tempting.
A turbine? haha, hey maybe. i don't know too much about model plane/rocket turbine engines. i bet they are expensive.
A PulseJet? god that'd be noisy. and i don't think a pulsejet could really output enough thrust.
How about just a Fan, perhaps ducted, electric or 2 stroke? good idea. it could even be a 4 stroke, but i think the best choice would be one of those crazy new rotarys i've had my eye on.
Without an obvious choice i'm throwing around some pretty crazy ideas in my head for this. Atm i'm thinking a pulsejet - liquid fuel combustion HYBRID of my own fanciful and completely untested design. Because i'd like the thrust to be able to be PULSED, the hybrid idea is to deliver seperate bubble "pellets" of fuel into a liquid fuel combustion rocket engine. The pellets/bubbles of liquid fuel going in at a constant speed. but when you instantly STOP the throttle - the spaces inbetween fuel pellets/bubbles act as enough of a buffer that the engine will just stop DEAD. So you have pulsed thrust.
I'm not nieve enough to think that this will in any way lead to a workable engine model, but i gotta write it down all the same. i'm like a little kid like that.
Spacecraft like landers have an RCS (Reaction Control System - basically attitude control) system because they don't fly fast enough, predictible enough, or even in a predictable atmosphere, to be able to use traditional Flight Control Surfaces (wings/rudders/flaps/etc) as aeroplanes do. So instead they use small rockets at strategic places on the craft to thrust the craft to meet the desired angle/attitude/rotation. A good example of this is the Harrier Jet. The Harrier jet "ducts" the thrust from it's main turbine engine through a series of pipes towards outlets in the wings - to control it's attitude while it is vertically taking off (VTOL). This is different to a lander, because a lander must be able to control it's attitude even while the main engine is not thrusting. but still the Harrier's method is worth taking note of.
A Harrier's RCS System
The method i'm thinking is similar to the Harrier's method of "ducted air". But instead of ducting the thrust from the main engine, you could have a central seperate source of pressurised air. A pressurised gas canister such as a small CO2 canister (picture) used for sodastream machines could be stored in a centralised location, then hooked up to a series of controllable valves which then pipe across to various outlets on strategic places of the lander. The shooting out of small bursts of pressurised gas in this manner may provide a workable RCS system, perhaps enough to last a few minutes of controlled flight per canister.
The user would have a traditional RC controller, and the Lander a traditional reciever. But the reciever would feed into the computer control system within the lander. The lander could also have a simple internal gyroscope, which would give the added bonus of allowing the user to press a panic button to signal to the lander's computer to level out. just like the W key in the lander game. These systems are currently available optimised for RC helicopter craft.
