How to stop application/service from destroying?

view story

http://stackoverflow.com – I have an application that has a single screen with a "start logging" button, which starts a service. After it is pressed, the button changes to a "stop logging" button and stops the service onClick. This service essentially grabs some data every minute and writes it to a couple of SQLite tables. The application is designed to be opened, start logging.. and then minimised and left in the background to run. However, the problem is that after a period of time, Android destroys/stops the process/service/activity so that it no longer logs data, and when the application is reopened, the screen is (HowTos)