If I broke a spoke on a wheel after only 1500 miles, I would suspect that the wheel was not built properly. Did it come on a new bike. or did you buy aftermarket wheels? Do you know who built them? What parts were used?
As others have suggested, you might want to make sure the wheel was properly stress-relieved and re-tensioned. If you aren't experienced with this, you might want to take the wheel (or wheels) to a shop and ask them to make sure everything is up to snuff.