Space Science-The challenge of leaving Earth.

In order to escape Earth's gravity we have to reach a speed of over 40,000 km/hr in just 6 minutes. This is called the escape velocity and requires the generation of enormous forces. Astronauts are pushed back into their seats so hard that say, an 80 kg astronaut will now weigh 240 kg. We say that the astronaut is experiencing a force of three g's. If not seated correctly blood can be forced from the head and cause a blackout. In order to achieve this speed modern day astronauts and cosmonauts must strap themselves on top of vehicles filled with hundreds of tons of highly explosive chemicals. Try telling that to Christopher Columbus and see if he would except the challenge.

What are the challenges of leaving Earth? NASA is already planning a manned mission to Mars. Unlike a trip to the moon a journey to Mars is logistically more complex. Long periods of isolation will surely test the astronauts psychological endurance and the dangers and hardships of space travel will compound the difficulty of a successful mission. So lets take an imaginary trip to Mars and gain a slight insight into the dangers faced by our modern day explorers.
Explorers of the past coped with many challenges. Many gave up their lives to the ferocity of the sea and wind and to hostile natives. However, no matter how hostile their environment proved to be they were always protected by the atmospheric blanket that surrounds our planet. A form of protection that we all take for granted unless of course you venture beyond the security of the Earth's atmosphere. One of the few comparisons between the early explorers and present day space travellers is their yearning for adventure and discovery.
A few other matters that need to be taken into account before we venture from the safety of Earth's atmosphere. Space is a highly dangerous place for any living organism making space travel a dangerous occupation. Without the protection of a space suit the low pressure environment would deplete the blood of all gases, including oxygen. The resulting hypoxia would result in loss of consciousness after, about 12 seconds and death would gradually follow after 2 minutes. At the extremely miniscule pressure of space blood and other body fluids start to boil at body temperature. This can cause damage to delicate blood vessels as the gases formed inside the body expand. However the blood vessels are elastic and can create their own pressure to a certain degree and compensate for the lack of external pressure. in the vacuum of space their is no medium, such as air, to distribute heat away from the body by convection or conduction. Also, the lack of air, apart from the obvious handicap of breathing, provides no way of moderating the external temperature, so an astronaut working in direct sunlight can experience temperatures of about 200^oC while in the shade the temperature would drop dramatically to below 100^oC. Here on Earth, air molecules absorb heat from the Sun and transfer it around through movement thus maintaining a steady comfortable temperature whether one is in the shade or in direct sunlight. Other dangers, such as exposure to radiation that is emitted by our very own Sun need to be managed and this is why the design of the space suit is so critical.

In order to escape Earth's gravity we have to reach a speed of over 40,000 km/hr in just 6 minutes. This is called the escape velocity and requires the generation of enormous forces. Astronauts are pushed back into their seats so hard that say, an 80 kg astronaut will now weigh 240 kg. We say that the astronaut is experiencing a force of three g's. If not seated correctly blood can be forced from the head and cause a blackout. In order to achieve this speed modern day astronauts and cosmonauts must strap themselves on top of vehicles filled with hundreds of tons of highly explosive chemicals. Try telling that to Christopher Columbus and see if he would except the challenge.
What is the difference between an astronaut and a cosmonaut? What was Yuri Gagarin famous for? What is the weight of an 120 kg astronaut when she is experiencing a force of 2 g's? Although the weight of the astronaut increases during lift off her mass does not. What is the difference between her mass and her weight? How does Earth's atmosphere moderate temperature here on Earth? What is the purpose of the ozone layer? What are the dangers that result from a lack of air in the vacuum of space?
Difficulty living with low gravity