ORIGINAL LECTURE
A trip to mars would definitely be challenging but scientists have proposed solutions to the problems the reading selection discusses.First of all, food, water and oxygen. Well astronauts can use hydroponics. Hydroponics is a technique for growing plants with their roots in water rather than in soil. It requires relatively little space. Using hydroponics, the astronauts should be able to cultivate food crops in the spacecraft. In addition, the hydroponic will grow plants with recycle waste water and release it as clean water vapor, which can be collected as drinking water. And of course, all plants absorb carbon dioxide and release oxygen. So thanks to hydroponics the astronauts will also have fresh air to breathe.Second, the effects of zero gravity. Over the last few decades, we have launched several space stations orbiting the earth. And a number of astronauts have spent many months on them in a zero gravity environment. These astronauts have learned to use several techniques to safely manage the effects of zero gravity. For example, regular exercise prevents the decrease in muscle mass. Likewise, taking vitamins and minerals like calcium slows down the decrease in astronauts’ bone density. Third, solar radiation. Astronauts traveling to Mars will be exposed to some solar radiation but this radiation will not be at dangerous levels all the time. The sun only releases dangerous amounts of radiation occasionally, during periods when it is particularly active. In order to avoid this threat, the spacecraft could be equipped with special instruments that monitor solar radiation and with a small shelter that shield against radiation but doesn’t add much weight to the ship. Most of the time, the astronauts will go about their normal business in unshielded areas of the spacecraft. But when their instruments detect increased radiation, they could stay in the small shielded area until the danger has passed.
Both the reading and the lecture discuss whether it is possible for humans to travel to Mars. The author provides some challenges that impede traveling to mars. On the other hand, the lecturer refutes this idea and asserts that all of the problems are solvable.
First, the passage suggests that the cargo capacity of space vehicles cannot support two years of travel. On the contrary, the speaker claims that astronauts do not need to take food, water, or oxygen supplies with themselves. Hydroponic is a way of cultivating plants by means of putting plants’ roots inside water instead of soil. This way of cultivating has three benefits. First of all, the plants can filter contaminated water and make it fresh. Second, these plants can absorb carbon dioxide and produce oxygen, and third, the plants are the source of food for astronauts. Therefore, astronauts do not need to be worried about their oxygen, food, or water.
Second, the writer claims that astronauts cannot tolerate a zero-gravity environment for many months. Conversely, the lecture asserts that astronauts have experienced the same condition inside the space vehicles orbiting around the earth for several months. They handled the detrimental effects of zero-gravity by exercising regularly and taking enough vitamins and nutrition, especially calcium.
Third, the author states that the sun’s radiation is lethal for astronauts. Alternatively, the lecturer contends that astronauts are not exposed to dangerous radiation all the time. Sun’s radiation occurs occasionally. Therefore, a small area of the spaceship can be shielded, and sensors can be placed on the space vehicle that are susceptible to the sun’s radiation. Whenever this hazardous radiation occurs, the sensors tell the astronauts, and they can manage to survive by going to the small shielded location until the danger is passed.