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

The stakes are high as Airbus must overcome 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 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," Auques said.

The idea is to recover the propulsion bay and the engine, which account for 80 percent of the launcher's total value, by protecting them with a heat shield as they make their way back to Earth.

Adeline is made to act as a stabiliser placed at the base of a launcher, complete with little wings and turboprop engine technology. As with most aircraft, fuel is stored in the wings.

The idea for used Space Tugs is that they wait at an altitude of 1,000 kilometres (620 miles), refuelled by new launchers with the help of satellite technology.

Once they have completed their mission, they are flown remotely like a drone to a landing strip.