Interstellar Travel - so you want to visit the stars?

Hopping around space on TV or in the movies looks quite easy. In real life, however, it is basically impossible (at least at this time - who knows about the future).

Why?

Suppose we could send a manned space ship off at 37,000 miles per hour (the speed of the NASA Voyager spacecraft). At this incredibly fast speed it would only take about 80,000 years to reach our nearest star (Proxima Centauri) just 4.2 light years away.

Clearly we just need to travel faster - right? Well, no one has figured out how to do that yet. It takes a lot of fuel to go fast and the more fuel you use the more you need to carry; the more you carry, the heavier you are; the heavier you are, the more fuel you need to carry. Anyone see a problem with this? Theoretical propulsion systems like the one pictured at right may someday help solve this problem but for now they are ideas. This site has more information and cool pictures.

Who knows when, but someday someone will figure out how to go really fast. Unfortunately, the interstellar speed limit is 300,000 km/s (the speed of light). According to the laws of physics and Albert Einstein we will never go any faster than that. Still, if we found a way to travel at the speed of light (which we cannot even come close to yet) it would still take 4.2 years to reach our nearest neighboring star and any planets orbiting it. That is a very long time to be locked in a small space ship. And what happens if you don't find a place to land when you get there? It's another 4.2 years to come home (and where would you store all the food for a 8.4 year journey?).

Source: Warp Drive When? by Marc G. Millis, http://www.grc.nasa.gov/WWW/PAO/html/warp/, accessed March 2003.