I'm holding on to a couple of short stories I wrote. One was about a small colony world becoming isolated as humans become more primitive and star travel fades, but some colony worlds have no natural salt. Yes, salt! Without salt the human body will start shutting down, hyponatremia sets in or whatever. The last refugee to end up on Dunga has a device that can produce salt, although not a huge amount.
The other was about 11 nations sending a male and female each 12-14 years old to a partially terraformed Mars (abandoned for 90 years) to learn how humans have to be genetically modified to survive there. You see, Mars cannot be fully terraformed, so it had been abandoned for nearly a century. Plants and wildlife on Mars had been genetically engineered for rapid evolution so nobody really knows what the kids should expect when they arrive.
