wisebabo writes "So here's a proposal by NASA to send landers to Europa to look for life. They are sending two landers because of the risks in landing on Europa. They got that right! First is the 500 million mile distance from the Sun, which will probably necessitate RTGs (Juno uses solar panels, but they are huge) and will cause at least an hour of lag time for communications. Then there is the intense gravitational field of Jupiter, which will require a lot of fuel to get into Jovian and then Europan orbit. (It's equivalent to traveling amongst the inner planets!) The radiation in space around Jupiter is tremendous, so the spacecraft may need to be 'armored' like Juno. Landing on Europa is going to be crazy; there aren't any hi-res maps of the landing areas (unlike Mars) and even if there were, the geography of Europa might change due to the shifting ice. Since there is no atmosphere, it'll be rockets down all the way; very expensive in terms of fuel — like landing on the Moon. Finally, who knows what the surface is like; is it a powder, rock hard, crumbly or slippery? In a couple respects, looking for life on Titan (where we've already landed one simple probe) would be a lot easier: dense atmosphere, no radiation, radar mapped from space, knowledge of surface). If only we could do both!"