In The Martian, an astronaut sacrificing himself in outer space is such a huge deal that if it happened today, countless people at home and abroad would undoubtedly jump out to say this and that.
In the film, the announcement was made immediately; Liu Zhou did not change that.
Aside from laying the groundwork for the later climax where the Earth's space agency discovers the male lead and launches a rescue mission, there were other reasons as well.
Chapter 308