TPO50

The reading addresses several issues that humans may face when traveling to Mars. On the other hand, the lecturer provides solutions, which are mainly proposed by scientists, to these problems individually.

First, sufficient supplies of food, water and oxygen is essential for human living. However, due to the limited cargo capacity of spacecrafts, it is impossible to put an amount required for traveling to Mars on board. To resolve this, the speaker introduces the concept of hydroponics, in which plants are cultivated with their roots in water instead of soil. That way, a steady food resource that occupies less space is available. What's more, this system can also recycle waste water and turn them into drinkable ones, while plants can generate fresh air, tackling the deficiency of two other necessary survival elements.

Second, the passage implies that zero-gravity environments can pose a threat on human bodies. To answer this, the professor points out that any astronauts have been working in space stations under zero gravity, and have learned numerous techniques so as to overcome health effects. For example, they exercise in space and take in minerals and vitamins to reduce the rapid loss of muscle mass and bone density.

Lastly, the article infers that since a shield will be too heavy, there are currently no means of protecting spaceships from being exposed to solar radiation. Nonetheless, the lecturer states that since sun activity actually bursts occasionally, there will only be certain times when humans need to avoid strong radiation. He suggests that humans should construct a small, light shelter on the spaceship, assisting it with a solar radiation monitor. That way, they can continue their work in unprotected areas during normal time periods and hide themselves in the shelter while boosted radiation attacks.