Australia is to start making its own military drones, officials have revealed, and former defence chief Sir Angus Houston said he expects that the "vast majority" of war fighting will be done by unmanned machines within half a century.

Colonel Andrew Jones, the Army's aviation program director, told a major military and defence industry gathering in Adelaide this week that Defence wanted Australian firms to help build a small, tough drone that soldiers can fit in backpacks and send out to spy on enemies on the battlefield.

Colonel Jones indicated it would be just a first step in what he called "sovereign" drone technology - or unmanned aerial vehicles as Defence prefers to call them. He said it could be the "start of something big" that included "more than just intelligence, surveillance and reconnaissance".

Beyond being eyes in the sky for soldiers, drones are most typically used to fire missiles on enemies such as terrorist organisations, and Australia has signalled plans to start using such weaponised unmanned vehicles.