NASA's 2016 budget sets its sights on Europa
In Arthur C. Clarke鈥檚 novel 鈥�2010: Odyssey Two,鈥� the sequel to the famous 鈥�2001: A Space Odyssey,鈥� aliens inhabiting the planet Jupiter send a message to an expedition from Earth. 鈥淎ll these worlds are yours except Europa. Attempt no landing there.鈥�
But this week Congress gave NASA a mandate to do just that. Don鈥檛 just visit Europa, Congress told NASA. Land there.
Europa is thought to be one of the most likely places in the solar system to host聽extraterrestrial life. Underneath its scarred, frozen surface is an ocean of liquid water that encircles the moon.聽Scientists say this ocean could be home to microbes that get energy from chemicals rather than from sunlight. If a mission to Europa confirms extraterrestrial life living in the ocean, it would lead to new discoveries about how the solar system, and life within it, formed.
NASA鈥檚 budget for 2016 is $19.2 billion, with $1.63 billion earmarked for planetary science and $175 million specifically for the "Jupiter Europa clipper mission."
The legislation that provides the money states that 鈥渢his mission shall include an orbiter with a lander that will include competitively selected instruments.鈥� That means Congress has officially tasked NASA with developing a craft that can orbit Europa, and a lander that can detach and reach the moon's surface.
What would such a lander look like? Some scientists have suggested small 鈥渃ubesats鈥� that could sample plumes of steam emanating from the moon鈥檚 surface. But to really study Europa, NASA needs to break at least partway through the moon鈥檚 icepack, closer to the ocean beneath. That means sending a 鈥渟oft lander鈥� craft that can locate a crevasse on the moon鈥檚 surface. Scientists at NASA鈥檚 Jet Propulsion Laboratory think the best way to deliver a lander without damaging delicate scientific instruments is with a sky crane similar to the one used to deposit the Curiosity rover safely on Mars.
Once on the surface of Europa, the lander would use small saw blades to collect ice samples from several inches below the surface. If it can reach a crevasse, it could use other instruments in its payload to learn about the composition of the ocean beneath 鈥� and, possibly, about microbes living there. The lander could probably last 10 days on Europa鈥檚 surface before it surrounding Jupiter, Ars Technica鈥檚 Eric Berger reports.
NASA鈥檚 current timeline calls for a Europa mission to launch in 2022, arriving by Jupiter either three years later (if it heads directly there) or six years later (if it first swings around Venus for a gravity assist). That doesn鈥檛 give NASA much time to design the lander, but it also won鈥檛 be the first time humans have attempted a landing in the outer solar system. In 2005, the Huygens craft separated from the Cassini orbiter and touched down on Saturn鈥檚 moon Titan, sending back data to the orbiter for about 90 minutes before its batteries ran dry.
