On August 7th, 1972, a massive solar flare went off on the Sun, bathing the moon in dangerous radiation. Had astronauts been there, they would have gotten sick, and possibly been killed.
If we're planning to spend time on the Moon, which we are, and if we're planning to spend even more time inside a spaceship traveling to Mars, which we are, the danger of encountering another deadly solar flare will go up. What should we do?
One strategy is to figure out when these flares are going to occur, so we can avoid them. That's called studying solar weather, which concerns the pattern of turbulence on the surface of the Sun.
Between 2010 and 2012 the Sun will be at Solar Maximum, which means it will be giving off a lot of flares. NASA is hoping to use this opportunity to learn as much as they can.
A new breed of spacecraft may do the trick. There's STEREO, the Solar Terrestrial Relations Observatory, the Solar Dynamics Observatory, and there's a satellite simply called Solar-B. These craft will take images of the solar flares as they occur, map the magnetic fields that cause them, and examine the Sun's overall magnetism as well.
Other proposed satellite missions might examine the Sun's corona, or be positioned on the other side of the Sun, allowing us to observe the whole thing.
With all those probes at work, NASA hopes to learn more about solar weather before sensitive equipment, and more sensitive astronauts, head back into space.