Problems of Space Travel

Space has no air

            Spacecraft will have to have storage room for oxygen. Atmospheric pressure is necessary for life. Your body has pressure. The atmosphere has pressure. These pressures must be about the same for human beings to breathe. Since there is no atmosphere in space, there is no atmospheric pressure.
            In space there would be pressure outward from our bodies, but no pressure on the human body from the outside. This would be fatal. Spacecraft, space stations, and space suits will have to be pressurized so that people inside them will have about the same atmospheric pressure on them that they have at sea level.

Space is dark

            Light rays travel from the sun through space, but there is no light. In order for light rays to be seen, they must be reflected from something. In space there are no particles to reflect light rays. It will be dark.
            When an object such as a spacecraft enters space, the light rays will be reflected from the craft. The craft will be a dazzling contrast to the dark space around it.
            An astronaut will have to be extremely cautious about his eyes. When he turns away from the sun, there will be complete darkness. The pupils of the eyes will adjust by opening wide. If he turns his head toward the bright spacecraft, it might be dangerous. The contrast is much greater than we are used to on earth. Of course, astronauts will be carefully trained never to look directly at the sun. That would be painful and very harmful.

Space has no heat

            Rays from the sun travel through space. But they must be absorbed by something to produce heat. If there is nothing to absorb the rays, there is no heat. When rays from the sun strike a spacecraft, two things will happen. Some of the rays will be reflected from it. Some will be absorbed and turned into heat energy.
            The atmosphere protects the earth from the intense rays of the sun. In space there will be no such protection. The spacecraft will have to be made so that it reflects some of the rays or it will be impossible for man to remain alive. The craft will have to absorb just enough rays for comfort.

Space has no sound

            Sound waves need to travel through some material, such as air, wood, or metal. Space has no material through which sound waves can travel. This means there are no sound waves so there is no sound except inside the craft or the space suit. However, radio waves can travel through space, so communication will probably not be a great problem.

Weightlessness in Spacecraft

            As a spacecraft reaches the point where it no longer gains or loses speed, an interesting thing will happen. The passengers and everything in the craft will become weightless. For that matter, so will the craft. When an object is weightless, it can no longer be dropped, but any slight push on it would move it. It would keep moving until it struck something such as the side of the craft.
            Objects such as furniture and equipment will have to be firmly anchored to the floor of the spacecraft. Magnetic shoes have been suggested as one way to anchor men to the spacecraft. The disadvantage to this is that a man's feet would be anchored firmly, while all the other parts of his body would be weightless.

Rays in Space

            The earth's atmosphere protects us by cutting down the amount of different kinds of rays that strike it. Some of these rays come from the sun. Others, called cosmic rays, come from outer space.
            Spacecraft, space stations, and space suits will have to be designed to protect people from these rays.

Meteors in Space

            When meteors enter the earth's atmosphere, friction caused by air makes them so hot that they soon burn up. In space, there is no air to cause friction. Meteors are moving like stray bullets in space, whizzing by at tremendous speeds, in no definite paths. A meteor no bigger than the period at the end of this sentence, traveling at its speed of twenty to sixty miles per second, could easily puncture a space suit, craft, or station.
            Spacecraft will probably be built with meteor bumpers. The bumper will be all around. the bumper may consist of an outer shell. Between this shell and the spacecraft may be a liquid which hardens whenever something strikes it. this kind of bumper will protect the craft much as a puncture-proof inner tube prevents the collapsing of a tire. The damage from tiny meteors might be stopped in this way. But if a meteor weighing an ounce or more struck a spacecraft, it would go right on through. No bumper could stop it. Perhaps a better way of protecting against meteors will be found. Some possibilities would be electric "force fields" – magnetic repulsion.

Spacecraft

            A spacecraft will need to be very powerful to carry the craft through the earth's atmosphere, beyond the earth's great gravitational pull and into space. The hardest problem has been to find a way to carry all the fuel required to lift a rocket against the earth's gravitational pull. Scientists have used multistage rockets for this purpose.
            Another problem in the construction of spacecraft is how to land them. The friction of air would cause a returning craft to become a flaming meteor and burn up in seconds. Spacecraft will have to be built so that they can reenter our atmosphere slowly. As they enter, they will need to circle gradually downward. By circling round and round, they will descend into the thicker air near the earth more slowly. Friction of air will not be as great, and the spacecraft will not become as hot.

Space Stations

            Since spacecraft will not be able to carry all the fuel they need for a trip, space stations will probably be built where craft can refuel. These space stations will probably be constructed somewhere beyond three hundred miles above the earth. They will revolve around the earth in a fixed orbit, just as the moon does. At a distance of 1,050 miles beyond the earth, such a space station will have to go around the earth at a speed of almost 16,000 miles per hour. At this speed, its centrifugal force will just equal the earth's gravity. It will remain in its orbit.