Experiments with man in space:

We have already discussed  the usefulness of space  flights in Blocks 3&4. One is able to make astronomical observations from satellites; get meteorological information; Obtain invaluable data on resources of the earth and the condition of crops and forests. The human urge to know the unknown and, if possible see what the conditions on the moon or planets are like, has also been a great factor in space exploration. Human ingenuity and creative power have given us the opportunity  to cany out much of this research and exploration with the help-of instruments which can be controlled from the earth. For example, samples of soil from the moon have.been brought back to earth by  automatic machines and rockets, without Actual human presence on  the moon. 

Nevertheless,  there is nothing like a human eye observing the panorama of the moon, and describing the scenery-beyond  what a camera can do  through a picture. But, space travel for human beings is a very difficult proposition, and in order to make it possible, lot of research has been done by  sending up other biological organisms and animals, such as virus, bacteria, mice, dogs and even monkeys. Human beings hate  to  travel in he  most unnatural circumstances-if  there is a single astronaut, he has absolutely no company for as long as he travels, and most unfamiliar scenes-looking  out of the window, he sees nothing except stars. This  loneliness, and ! absence of sensations from outside has been found to be a source of great mental stress. Man is a social animal, and he has to receive sensations through his eyes, ears, nose and skinetc.. to feel normal.

Travelling in a satellite, one feels "weightless"-if  you turn a glass upside down the liquid aoes not rail out! So,  food also does not naturally move down the throat--even water is not easy to swallow. It seems our whole body-(digestive  system, and even blood circulation) is accustomed to earth's gravity, and if  it is nullified, we cannot be at ease. Even movement of muscles is difficult. The air inside the space vehicle is kept under artificial pressure, because outside the vehicle there is near absolute vacuum and no sound of any kind can reach the space craft. Of course, there are great problems in washing, or taking a bath or in passing  stools.

Obviously any space traveller would feel out of sorts -  but that is a mild word, he or she can feel absolutely confused, lethargic and psychologically unstable. But practice  is a great help. Modern astronauts go through a long period of training.  If  they know what to  expect in space, they are mentally and physically prepared for it. Weightlessness is also simulatd so  that a space man or woman can be adjusted to its peculiarities. Communication iinow much better, the travellers can receive television pictures and can make telephone calls. They are made to take exercise. It  is now the practice to have a group of men, or men and women in space rather than single persons. That is how, in one Soviet space craft, people have spent more than a year at one stretch without adverse effects. The tasks of control and communication are also numerous for the spacemen and hence a team  is needed. All this shows  that our body and mind are attuned to live under normal conditions of pressure,  gravity, sensations and communication.

Abnormal physical environment puts our system under great stress, which shows serious physical as well as psychological  effects. But many of these aspects have come to light only because space had to be conquered and human beings had to get adjusted to new living conditions.  If a colony is made on the moon or elsewhere, there will be other conditions to be experienced, and hopefully man will prove equal to the task.