Science, especially modern science, has been advancing at an astonishing rate. Within the last century, we have discovered that the Milky Way is one galaxy in a sea of billions, and within the last 20 years, we have confirmed the existence of a thousand exoplanets (with a few thousand more in the works). These observations have fundamentally changed our perception of the universe and our place in it. Within the next 30 years, NASA hopes to answer one of humanity's oldest questions, "are we alone?"
Recently, NASA laid out a 30 year plan for the types of questions they want answered and science that they want to accomplish. Over the next 3 decades, NASA is going to tackle some of the most profound questions asked by humanity: "are we alone", "how did we get here", and "how does our universe work." Answering these questions (or, at least making the attempt) will have a profound impact on science, technology, and what it means to be human.
The discovery of exoplanets have opened the possibility that life might also exist outside of our solar system (quick history lesson: scientists have thought exoplanets existed since we understood what the stars were - it made sense - if the points of light in the sky were the same as our Sun than those points of light might also have planets in orbit around them, just as ours does; however, we didn't have the technology to find them until very recently). At the moment, our ability to study the conditions on an exoplanet is very limited. We can make crude measurements of the atmosphere (giving us a general idea of what it's made of), we can easily discern the planet's mass, and we know if the planet exists in the host star's habitable zone - that's about as far as we can go.
The James Webb Space Telescope and the Large UV optical IR Surveyor (set to launch in 2018 and the 2020s respectively) will study the atmospheres of exoplanets in far more detail. In addition, NASA is launching the WFIRST-AFTA mission which will look for and study rogue planets.
Of the planed missions, few are as exciting as the ExoEarth Mapper mission. If successful, this mission will combine observations made by several ground and space telescopes and will allow us to resolve images of these exoplanets. Instead of a little point of light, NASA hopes the ExoEarth Mapper will allow scientists to identify continents and oceans on the planet's surface (and possibly signs of intelligent life). I'd like you to pause for a moment and think about how awesome it would be to conduct a mapping survey of a planet hundreds of light-years away.
NASA is already in the process of answering the "how did we get here" question. Missions to Mars (such as Curiosity) and future possible missions to the icy moons of Saturn and Jupiter seek to study biological life and it's origins (assuming any is to be found). NASA also hopes to better understand the history of the Milky Way, how stars, dust, and gas move over cosmic time, and generally study the history/evolution of the universe.
To accomplish this mission and answer these questions, NASA will need to push technology past it's current limit. It will require the construction of better, stronger, more sensitive, lighter, sharper, faster, more precise instruments, programs, and computers. Human ingenuity will be challenged like never before. The technological spin-offs are also sure to be profound and our understanding of the universe is certain to be better.