Final answer:
With the fastest spacecraft speeds currently possible around 20 km/s, it would take almost 80,000 years to reach the nearest star, Proxima Centauri, which is 4.3 light-years away. Achieving practical travel times to neighboring stars would require speeds close to the speed of light, which is currently beyond our technological capabilities due to the enormous energy and financial costs involved.
Step-by-step explanation:
The speed of the fastest spacecraft currently possible, as mentioned around 20 km/s, is significantly slower than what would be required for interstellar travel. Based on information from faster spacecraft, such as the Parker Solar Probe (up to 68.6 km/s) and Voyager 1 (which would hypothetically travel at 70 km/s after breaking free of the solar system), we understand that even these speeds are insufficient for practical travel times to the stars. Specifically, if Voyager 1 traveled at 70 km/s, it would still take about 20,000 years to reach the nearest star.
Considering Proxima Centauri, the nearest star to our sun which is 4.3 light-years away, even if we could reach a speed of 20 km/s with a spaceship, it would take almost 80,000 years to arrive. To travel to neighboring stars within a human lifespan, we would need to achieve speeds close to the speed of light, but the energy and financial costs for such speeds become astronomical. This highlights the immense challenges for interstellar travel posed by the vast distances between stars.