After 50+ years of operating in space, we don't know everything about the space environment and the "space weather" created by solar flares and charged particles.
The University of Colorado at Boulder has put out this press release:
"The University of Colorado at Boulder has been awarded $840,000 from the National Science Foundation for students to build a tiny spacecraft to observe energetic particles in space that should give scientists a better understanding of solar flares and their interaction with Earth's atmosphere."
UC-Boulder's Laboratory for Atmospheric and Space Physics (LASP) has built several spacecraft and many instruments with student participation. (I've visited up there and was very impressed.) The Colorado Student Space Weather Experiment will be housed in a spacecraft weighing only 2.5kg. The mission will launch around 2012.