LightShip – ESA's martian tug

Mars can be as far away from Earth as 400 million km. To make trips to the Red Planet more frequent and affordable for science and exploration, European engineers came up with a mission concept for a reusable tug, or interplanetary transfer service.

The martian tug promises to open a market of low-cost missions to Mars for a broader community. ESA calls it LightShip.