Well cool! I must not read carefully enough and just voiced out what seemed unclear to me.

Looking at it now... on number 1 I was actually diametrically wrong. If Tom was 24-25 then with that speed they traveled already 48-50 Earth years. Thus, oxygen tanks should really be depleted just like you wrote.

And I misread this ...

nine people were chosen from each race of human there is
So you said 18 races x 9. Got it. There are different race qualifications. I've seen somewhere there are only 4 but have seen those when there were listed many more. 18 sounds good enough. And yeah it really makes no difference. I misread 9 of each race. I thought it was 9 altogether.

Gregory wasn’t an American pure-breed as evident in his looks; his father was presumed to be the American and the mother Australian.

I guess I didn't understand what was the reason why this information is pertinent. Why was it so important for the reader to know this. BTW, which accent did Gregory have American or Australian? Also, I am confused about why it was evident from his look that he was not a pure breed American. Was his mom Australian aboriginal? I was trying to imagine this and met with some lack of info. So he had the picture of his parents. Ok. Still, you know something that I don't.

Anyhow cool! Now, your overall thinking pattern is much clearer to me. I feel like we've spent some time together talking about the future. )))

Good luck with the contest!