This site is a great reference for telescopes. I am getting a telescope soon. First of all, make sure you get a good look at the Moon. Also look for Venus, Mars, Jupiter and Saturn. They should all stick out in the night sky.
Power plants use the energy produced from flowing water.
Sometimes dams are set up along rivers. The shuttle is mainly made of aluminum, with some titanium and boron composites in the back near the thrusters. One of the major constraints on sending balloons to space is the amount of time a balloon can stay aloft. However, NASA has been working on this, and is working on an Ultra Long Duration Balloon which will be able to remain in the upper atmosphere for up to 100 days. It's hard to say exactly what will be the most advanced spacecraft 25 years from now, simply because out technology is changing so quickly.