Project Icarus is a 5 year study, headed by scientists from the Tau Zero Foundation, a non-profit group of scientists dedicated to interstellar spaceflight. The ambition of the project is designing a spacecraft and a plan for a future space mission to another planetary system.
At the moment no technology exists that would allow such a journey in a reasonable timeframe. Icarus works with the assumption that we will one day possess technology that allows us to send probes to other stars, reaching the star within 100 years after launch. Given realistic propulsion options, and the requirement that the spacecraft can slow down to orbit its target, the target star cannot be more than 15 light-years from Earth, although given that the timeframe is 100 years, the distance will likely be much less.
One of the factors will of course be which stars in a 15 lightyear radius will have planets. Of the 38 stellar systems (some containing more than one star) only 2 are known to have planets so far. Epsilon Eridani, 10.5 light-years away, and the red dwarf GJ 674 at a distance of 14.8 light-years.
Just outside the radius there are another 3 stars with planetary systems.
There has however to date not been a systematic survey for planets of the closest stars, which in the near future could reveal a lot more planets, by current estimates around 15 or 16.
|Artists Impression of the planet Epsilon Eridani b (Credit: NASA, ESA)|
Thus, although currently we cannot identify an obvious specific target for Icarus, when the time comes to actually build a starship, we will have a very good idea where to send it.
My bests bet lies with the nearest system. Even though no planets have been found there yet, due to the system being the closest to the solar system at 4.4 lightyears, it will likely be chosen as a target for the first human spacecraft to fly under the light of another star.