BRITE Constellation - Australian photometry mission

It's not quite a dedicated exoplanet mission but it could potentially detect extrasolar planets.

Do have nanosatellites a role in detecting exoplanets?
http://arxiv.org/abs/1211.5439

Quote :

In December 2012, Austria will launch its first two satellites: UniBRITE and BRITE-Austria. This is the first pair of three, forming a network called BRITE-Constellation. The other pairs being contributed by Canada and Poland. The primary goal of BRITE-Constellation is the exploration of short term intensity variations of bright stars (V>6 mag) for a few years. For each satellite pair, one will employ a blue filter and the other a red filter. With the discovery of the first exoplanet in 1992, more than 800 have been detected since. The high-precision photometry from the BRITE instrument will enable a transit search for exoplanets around bright stars. To estimate the capability of BRITE to detect planets, we include in our calculations technical constraints, such as photometric noise levels for stars accessible by BRITE, the duty cycle and duration of observations. The most important parameter is the fraction of stars harboring a planet. Our simulation is based on 2695 stars distributed over the entire sky. Kepler data indicate that at minimum 34% of all stars are orbited by at least one of five different planetary sizes: Earth, Super-Earth, Uranus, Jupiter and Super-Jupiter. Depending on the duty cycle and duration of the observations, about six planets should be detectable in 180 days, of which about five of them being of Jupiter size.