AS3: Always reloading swf? Why? - actionscript-3

Question

I have a Homepage, which plays a mainSWF. In this mainSWF I have a loader, that loads external swfs from my server. With a button you can unload this external swfs an load a different one. Some of this swfs are 30mb big.
So, here is my problem:
The external SWFs are never saved temporary, or something like that. So you have to load all the 30mb everytime again. Is there a workaround or a configuration or something?
Thanks for answering!
var _swfLoader:Loader;
var _swfContent:MovieClip;
function loadSWF(path:String):void {
var _req:URLRequest = new URLRequest();
_req.url = path;
_swfLoader = new Loader();
setupListeners(_swfLoader.contentLoaderInfo);
_swfLoader.load(_req);
}
function setupListeners(dispatcher:IEventDispatcher):void {
dispatcher.addEventListener(Event.COMPLETE, addSWF);
dispatcher.addEventListener(ProgressEvent.PROGRESS, preloadSWF);
}
function preloadSWF(event:ProgressEvent):void {
var _perc:int = (event.bytesLoaded / event.bytesTotal) * 100;
// swfPreloader.percentTF.text = _perc + "%";
}
function addSWF(event:Event):void {
event.target.removeEventListener(Event.COMPLETE, addSWF);
event.target.removeEventListener(ProgressEvent.PROGRESS, preloadSWF);
_swfContent = event.target.content;
_swfContent.screen_demo_close_btn.addEventListener(MouseEvent.CLICK, unloadSWF);
addChild(_swfContent);
}
function unloadSWF(event:Event):void {
if (MovieClip(root).onDemo == 1) {
MovieClip(root).resetDevices();
_swfLoader.unloadAndStop();
removeChild(_swfContent);
_swfContent = null;
MovieClip(root).onDemo = 0;
}
}