This is one of those articles I’ve been meaning to write for a long time: How long would the interstellar transit be from Earth to the nearest star (and no, I don’t mean the Sun)? It turns out that there is no practical way, using today’s available technology that we can travel to Proxima Centauri (a red dwarf star, 4.33 light years from the Solar System). This is a shame as there are so many stars and so many exoplanets to explore, which space enthusiast wouldn’t want to envisage interstellar space travel? However, there may be help at hand, using modern technology and materials; we might be able to mount a manned expedition to Proxima lasting a little under a century…
So how long would it take? Using two examples, the SMART-1 propulsion system and Voyager’s gravitational sling-shot, we arrive at prohibitively long time scales. Using SMART-1’s ion thrusters (economical but very slow), we have an upper limit of 81,000 years to travel to Proxima Centauri (that’s 2700 generations!). Next up, gravitational assists (using the gas giants Jupiter and Saturn to boost a spacecraft into deep space). Voyager for example is travelling quite a lick through the limits of the outer Solar System. At 38,000 miles/hr, Voyager would take 76,000 years (2,500 generations) to travel to Proxima Centauri. Still not good, it seems we need to travel at an appreciable percentage of the speed of light before we turn the 4.33 light year trip from an epoch into a human lifetime.
There is one technology that does promise to succeed in this goal. Nuclear pulse propulsion could push a manned spaceship to 5% the speed of light. 5% of 4.33 light years is approximately 85 years… This is a very interesting concept, but the radioactive fallout is problematic to say the least.
For more, check out my Universe Today article How Long Would it Take to Travel to the Nearest Star? and have your say….