That is not possible - Aperture will always store all versions of an image in the same project. You can have different versions in different albums, however.
If you really need different versions in different projects, you have to create a new image and duplicate your image by dragging it with the options-key held down to the other project. Then you can delete the duplicate versions in the second project. Only this would be really wasteful, since you would create duplicate original files.
Try o achieve, what you want to do by creating albums instead, if it is possible. Then you do not need to duplicate the originals.
maybe a good Q to ask here is whether each version really does take up 19mb of space = ie original and version 2 and version 3 = or are 2 and 3 not really taking up that much space? tht might affect how I work with this == I could create an album I suppose but I wanted the project because I wanted a discrete set of images apart from the other projects....thanks
Versions do not need as much space as the original image files. Aperture does not really create an image file for the versions, it only stores a description of the applied adjustments and added metadata. These do not take up much space. For each image version will be a thumbnail image created, and optionally a preview image, if you have Aperture set to render previews. But these files will all be created only once for each version. Adding them to albums does not need much space, because only references will be stored.