根据短文内容，完成下面的句子。The altitude is so _______ that there is no atmospher

根据短文内容，完成下面的句子。

The altitude is so _______ that there is no atmosphere which protects the life on the earth. At the same time, the astronauts usually meet with some problems, such as ________ problem, radiation problem, breathing problem, heat problem and so on.