European aircraft and aerospace giant Airbus has unveiled plans for a reusable space rocket launcher that should be ready in 2025, which the firm says will be radically different from the concept of rival US firm Space X.

Airbus must overcome significant technical and financial challenges, while the Space X company owned by South African-born billionaire Elon Musk, co-founder of PayPal, is already experimenting with its model.

Since 2010, a team of engineers has been secretly working at an Airbus warehouse at Les Mureaux, just outside Paris, looking for ways to reuse space rocket launchers.

They have a difficult task ahead because they must ensure that reuse ends up costing less than sticking to classic single-use models.

Now, as they give journalists access to their site, it appears their project might end up working.

Airbus has baptised the two phases of its reusable launcher concept Adeline and Space Tugs.

"The main stage launches and operates the rocket in the first phase of its journey. The later stage comes into action in the second part," said Francois Auque, director of Airbus’s Defence and Space programme.

Adeline, which stands for ADvanced Expendable Launcher with INnovative engine Economy, is original because it combines space technology with aeronautics, said Herve Gilibert, technical director at Airbus Defence and Space.

"In order to reuse the main stage, we bring back the most expensive parts and try to make them in a way that they become much cheaper to reuse them than to make new ones," Auque said.

The idea is to recover the propulsion bay and the engine, which account for 80 percent of the launcher’s total value, by putting them behind a heat shield that will protect them as they come back to Earth.