Experiments launching into the Alaska sky soon: One to measure the sources of X-rays that hurtle toward Earth from elsewhere in our galaxy and three other rockets that will each carry 50 gallons of water to attempt to measure the impact of short-term changes in layers of microscopic ice particles, also known as Polar Mesospheric Clouds (PMCs). Get the details on the missions and how to watch the launches: http://go.nasa.gov/2CUv5kl | NASA - National Aeronautics and Space Administration