LightSail-1 - This is wonderful!

https://www.youtube.com/watch?feature=player_embedded&v=-JRAPo1SZe8
http://www.planetary.org/explore/projects/lightsail-solar-sailing/
You might have heard of CubeSats - a very small, customisable type of satellite designed to "hitch-hike" on a full-scale mission; sometimes dozens of them can be sent up at once. The idea is to provide an affordable way for universities and even individuals to get scientific instruments into Earth orbit. They've been doing quite well, but one limitation is that they don't have any propulsion of their own. The Planetary Society are now trying to take them a step further by fitting one with a solar sail. If it works, LightSail-1 will be the first solar sail craft that can actually be steered, and only the second to fly at all (after the Japanese IKAROS, which launched in 2010 and is still up there). It's scheduled to launch in April 2016.

So just thinking about that... if it takes off, then if a future space mission can't afford to build a ship, they send a sailing dinghy.
I like that.