Kepler
Launch Date: 2007
In the near future NASA is planning on sending a discovery mission called Kepler. It will be sent to other planets to find out if there are planets outside of the solar system. Kepler will observe the decrease in light detected from the parent star. When a planet passes in front of the parent star, it blocks some light. This is obviously caused by a planet, and it will most likely happen again. This will determine if there is a planet rotating around the parent star.
Space Interferometry
Launch Date: 2009
NASA is planning another mission in the next six years. It will be called Space Interferometry Mission or SIM. It will figure out where stars are and distances of stars. SIM will be 700 times more accurate.
Terrestrial Planet Finder
Launch Date 2015
This will look for planets outside of our solar system. It will look at their formation and how they developed.
Single Aperture Far-Infrared Observatory (SAFIR)
Launch Date: Between 2015-2020
Life Finder
Launch Date: 2020
When NASA identifies habitable planets, Life Finder will send telescopes at even larger distances to detect chemicals that actually reveal life on other planets.
In my opinion NASA will find a way to send humans to Mars. Right now we are sending Mars rovers to the Red Planet. Once we start sending humans to Mars we will start to find that there is life on Mars. The Mars Rover just takes pictures so the NASA scientists can figure out if the planet is livable.
I also think that we will start to explore other planets. NASA will find a way to make a shuttle to go all the way to Pluto. I think that will be in the very distant future.
Another thing I think will happen would be for the U.S. to start exploring other galaxies. If we can get out of our own galaxy there may be other planets that have life on them.