Characterizing the icy satellite from afar during flybys is Europa Multiple Flyby Mission's primary goal, which is set to launch in the mid-2020s. Although NASA previously announced that there will be no lander, the agency has somewhat reconsidered the idea.

In the American Institute of Aeronautics and Astronautics' Space 2015 conference in Pasadena, Europa, scientists revealed that they could launch a landing probe in the ocean-harboring satellite of Jupiter.

"We are actively pursuing the possibility of a lander," said Robert Pappalardo, Europa project scientist at NASA's Jet Propulsion Laboratory (JPL).

"NASA has asked us to investigate: What would it take? How much would it cost? Could we put a small surface package on Europa with this mission?" Pappalardo added.

Previous studies revealed that deep below the crust of the satellite's icy world is a huge subsurface ocean two times deeper than the Earth's deepest spot (estimated to be 12 miles deep). It is believed to have coexisted with the solar system 4.5 billion years ago. There are actually five other moons thought to harbor a similar surface; however, only two are touching the rocky mantle, namely, Jupiter's Europa and Saturn's Enceladus, which could trigger interesting chemical reactions that can lead to the conception of life.

Deputy scientist at JPL's Solar System Exploration Directorate Kevin Hand said that "when it comes to habitability, we'd like to have the knowledge that the potentially habitable environment has been there for a significant duration."

But this is a no easy task. The Europa mission is set to use different tools, including high-resolution camera, a heat detector and an ice-penetrating radar. This should give scientists a glimpse of the moon's composition, nature of the subsurface ocean, and its ability to host life.

"We actually don't know what the surface of Europa looks like at the scale of this table, at the scale of a lander -- if it's smooth, if it's incredibly rough, if it's full of spikes. Without knowing what the surface even looks like, it's difficult to design a lander that could survive," said Curt Niebur, Europa program scientist at NASA's Washington headquarters.

With a lot of things still to consider, Pappalardo expects that NASA will make its final decision by the end of 2015. "By the end of this year, we should have an idea of how that's looking," he said.