Yes; humans can travel to other stars, but not with current technology

By MUNGAI KIHANYA

The Sunday Nation

Nairobi,

12 October 2025

Will humans ever be able to travel to another star system? I am optimistic, so my answer is yes, but not with our current technology. We have to invent a new method of travelling through space.

Consider this: The Parker Solar Probe holds the record for the fastest man-made object in history. Last year it reached 690,000km/h as it hurtled over the sun’s atmosphere taking important scientific measurements. Of course, breaking the speed record was not the purpose of the mission!

This great speed was achieved by letting the space probe fall towards the sun but at an angle the makes it miss a collision. So, in reality, it wasn’t accelerated by man-made means. This trajectory gives the probe a highly elongated orbit that takes it from 60 million km away to just 4.5 million km above the sun’s surface.

It is not practicable to achieve such high speeds using rockets as accelerators – the amount of fuel needed is just too much to carry. We never think about it, but, every time you put petrol in a car before a journey, the car has to carry it along on the trip. Indeed, pilots have to carefully calculate the amount of fuel to load up. Extra fuel in an aeroplane significantly increases the rate of consumption per km because of the added weight – they don’t simply say “jaza tank”!

Nevertheless, if a probe travelled at 690,000km/h, it would take about 8,700 hours to travel from the sun to the orbit of Pluto, 6 billion km away. That’s about one year! To be clear, the Parker Space Probe is not travelling in a straight path. It is in an orbit around the sun, so, it will never get anywhere near Pluto.

At 690,000km/h, an object can travel to the present location of Voyager 1 (the farthest man-made object) in about 4.5 years. For comparison, Voyager 1 has been flying for the last 48 years.

The nearest star from the sun is about 40 trillion km away. That is, the number 4 followed by 13 zeroes – 40,000,000,000,000km! This is so far away that the light from this star take more that four years to reach to us. At our record speed of 690,000km/h, a space probe would take 6,600 years to get there.

This is the reason I say that our current technology of rockets and gravity assisted slingshots cannot take us to another star system. The distances are simply too great. But I have a lot of faith in human ingenuity. One day we shall find a way!