From the size of a milk crate to the size of a car, NASA's Mars rovers have gotten bigger and more powerful since the first such landing in 1997. The latest effort, Curiosity, landed at Gale Crater in 2012 and is expected to last the better part of a decade. But its durability and powerful rock-analyzing laboratory came at a price of $2 billion.
Curiosity's science return so far includes finding extensive evidence of organics and water in its zone, although critics have said its drill is under-used. NASA is now planning a similarly sized rover to leave for Mars in 2020. But is there a way to add more science without overburdening on cost?
PHOTOS: Satellite ‘Flock' Launched From ISS Cubesat Cannon
As multi-million dollar spacecraft crawl across our solar system, they could bring smaller passengers with them. These tiny vehicles are called CubeSats and they've done a great job colonizing low Earth orbit since 2003. (At least one launched that year, from the University of Tokyo, was still operational as of 2014.) Their ability to survive beyond our planet is untested - even though from experience, the community knows what parts are most likely to survive. Nevertheless, NASA, the European Space Agency and several other groups are thinking about how to make this exploration happen in the next few years.