I'm very interested in what you've been doing with this.
Have you touched on asteroid mining at all?. Treating them as a limitless forest plot that can be harvested over and over again but with a variable amount of hammers generated each turn until the plot is exhausted. There may also be a bonus resource discovered. Like a rich Iron, Titanium, Berrylium, Neutronium Ore deposit (Randomly generated) or a Dilithium Crystal node (for the Trekkers amongst us)
The plot would have a random minimum and maximum value of hammers. E.G plot a of the asteroids has a minimum hammer value of 600 and a maximum of 2000. Each turn a mining ship works the plot it harvest between 40 and 90 hammers from the total. Placing more than 2 mining ships in the same plot runs the risk of accidents. Collisions in space, mining accidents resulting in the loss of a mining ship or 2 and all the resources they mined that turn.
It all sounds very simple to me but then i don't understand half of what i'm looking at in XML at the moment. So, please forgive my noobness if this is not a possiblity