So there's this asteroid, 99942 Apophis, that will make a "close approach to" (read: "near miss of") Earth in 2029 and possibly again in 2036. Don't worry, we're probably fine -- there are lots of way more dangerous asteroids coming our way...just not quite so soon. Before an asteroid hits Earth (and one eventually will -- it has happened before), we need a plan to take it out, Deep Impact/Armageddon style -- or at least a plan to visit and study the near-miss asteroids, since they'll be in the neighborhood. But how exactly do we get ready for that? We don't even have a Space Shuttle anymore.
In this video, Neil DeGrasse Tyson and various NASA and NOAA scientists explain NASA's NEEMO (NASA Extreme Environment Mission Operations) program, which has astronauts and scientists living underwater, "to work on various techniques for exploring asteroids." The work is well underway to figure out how to interact with asteroids once we get there -- which is encouraging, as I hadn't heard about NEEMO until seeing this video. While they are not designing laser cannons, they are figuring out how astronauts would interact with the surface of asteroids, which is a pretty good first step towards sending Bruce Willis up there. Check it out:
Motherboard TV has an excellent article related to the video above, including information that budget cuts have affected NEEMO already.
See also: NDT's Senate testimony about NASA funding.