This is the first time a commercial payload has been put into orbit from a submarine.

The unique launch is the first commercial space launch in the history of the Russian Navy, officials say.

The satellites will be used for environmental research

The satellites, called TUBSAT-N and TUBSAT N-1, reached their correct orbits after being launched at 0315 GMT on Tuesday.

The satellites will be used to collect environmental data from the world's oceans by scientists from the University of Berlin.

They were fired from beneath the Barents Sea using ballistic missile technology developed for military purposes.

Putting satellites into low earth orbit is technically only a small step from delivering long-range warheads.

The Russians have been offering the submarine launch facility as a commercial service for some time and have already conducted sub-orbital test flights.

The benefits of a submarine launch are primarily safety combined with the ease of putting a payload into a specified orbit.

For safety reasons, there are serious restrictions on the directions rockets can be launched from sites to land.

Submarine based missiles are only big enough for small satellites

But this latest success does not mean the world's space agencies will be all launching at sea.

Submarine-based missiles are only big enough to launch small research satellites and will never be able to launch large communications or interplanetary space probes.

But the success of the launch is expected to open up a valuable niche in the space markets for the Russians.