Avatar science fallout: using antimatter to get to Alpha Centauri and other nearby stars

SpaceRip uploaded a video a few days ago using the story in Avatar as a starting point for an explanation of our current rocket technology vs. the type of technology we will need to see in order to be able to make it to other star systems like that one. The video is a bit over 20 minutes in length and aside from the part a bit after halfway through that just goes over global warming (a subject worth talking about, mind you, but not half as interesting as the rest) is quite good. The voice is the same guy that does all the Space.com videos as well.

One thing it doesn't explicitly mention about improvements in propulsion is that there are two reasons why advances are so important: 1) More efficient propulsion means a higher velocity can be achieved with the same amount of fuel, but also 2) more efficient propulsion also means that either a much lighter craft can be sent up (achieving much higher velocities) or more instruments can be added if the budget allows it.

Taking the Space Shuttle as an example, it has a mass of 2030 tons at liftoff while the orbiter itself is only 78 tons. The external tank alone is 1670 tons. The video mentions that using antimatter the same craft could be launched with an amount of fuel the size of a quarter. Using a much more efficient fuel like that would mean that even a craft many times the size of the current Shuttle could be launched with barely a noticeable amount of fuel.

The video is also correct in that if a planet thought to contain life were to be discovered around Alpha Centauri (or another close star) the planning for a mission to that location would begin almost immediately. If we're lucky then WISE will discover a brown dwarf even closer than that and for all we know life could be present on a planet orbiting that due to tidal heating.