How long would it take for an astronaut to reach the closest star?
closest star is Proxima centuri,
It is about 4.3 llight years away. lighrt years is 9,460,528,400,000 kilometers..So mulitply this with 4.3 years.Maximum speed of our rockets are 23 KM/sec..Now calculate yourself.
NASa New horizons comaprison. In 2015, NASA's New Horizons probe completed its 3-billion-mile (4.8 billion km) journey to Pluto after traveling for about 9.5 years. The spacecraft traveled at speeds topping 52,000 mph (84,000 km/h). At that rate, it would take New Horizons about 54,400 years to reach Proxima Centauri.Aug 24, 2016
Part answer from Wikipedia.