The reading passage claims that scientists should take many problems into consideration when it comes to the human mission to Mars and for this mission, some difficulties would be needed to resolve.

The reading passage claims that scientists should take many problems into consideration when it comes to the human mission to Mars and for this mission, some difficulties would be needed to resolve. However, the lecturer finds all the ideas dubious and presents some evidence to refute them all. First, the author claims that back and forth travel to the Mars is along with trials and tribulations in case of water, oxygen and food supply because the travel will take at least two years. On the contrary, the lecturer brings up the idea that a new technique called Hydroponic can provide an opportunity for Astronauts to cultivate crop plants in the spacecraft and make the best use of collected water and oxygen released by plants. Furthermore, the author points out that zero-gravity environment in the space will have deleterious effects on the body of humans and create some problems for their muscles and bones. Conversely, the professor underlines the fact that vast majorities of Astronauts are adept enough to travel to the Mars because they learn how to cope with the zero-gravity environment through regular practices. Finally, as set forth by the author astronauts will be subjected to dangerous solar radiation emitted by the sun and building a shield at the present time is impossible. In contrast, the speaker dismisses this issue due to the fact that radiation emitted by the sun is not dangerous for the whole time. Indeed this solar radiation can affects astronauts occasionally and they can protect themselves through special instruments, which do not add to the weight of the spacecraft.