To venture into space, man, first of all, has to develop an efficient means of travel. Despite the rockets and space shuttles that man has now that can travel at many kilometres per second, the speed is still very slow. It takes months just to reach Venus, our next-door planetary neighbour. To go to planets further away it would take years. Interstellar travel is definitely out of the question now.
According to current science, there is a speed limit in the universe. This limit is the speed of light which is an astounding 300,000 kilometres per second. Even at this speed it still takes about eleven minutes for light from the Sun to reach our planet. So at the snail-pace 10 kilometres per second of our rockets, it is obvious why our speed is grossly inadequate.
Even if we have the speed of travel, we still have to know the place we are going to. We have to know the conditions and thus devise steps to handle any situation that may crop up. It is foolish just to go to, say, a planet and land there. The space travellers will surely perish if they do not know how to cope with the conditions of the planets.
Man is a creature evolved from the Earth. Earth is his home and his body is made especially for living here. Biologically then space travel presents Man with a formidable challenge. At the present stage of our space travel, man is restricted to orbiting the Earth or landing on the moon. It is an established fact that the body undergoes biological changes outside the Earth. An example is that the bones lose their mass and man has to readjust to conditions on Earth when he returns. This is only one problem that has to be resolved. What about those that come up on long space journeys? No one knows for sure.
If a trip to Mats takes months, how long will it take for a trip to the nearest star? The nearest star is four light-years away, that is, it takes light four years from it to reach our planet. It would take generations for a present spaceship to reach the star. No man can live for generations. So how are we going to send someone there? He would be long dead before he reaches it. Perhaps he and his family can be sent on the trip so that his later descendants can reach it. The question is is it worth the long trip? Another question is: how are we going to equip a spaceship that can sustain life for generations?
Such questions have to be answered before a man can really venture into space. Many more will arise and have to be solved. It is obvious, space travel is not a simple thing. It is a huge and complex matter that man has to tackle if he intends to go further. The present generation will definitely not be space travellers. Perhaps many generations later man would have developed the means to go towards the stars.