Welcome to the Amber Zone! This site is all about Space Adventure. Amber Zone is an old format for short adventures used in the classic version of the RPG Traveller. (But the adventures should be usable for any version of Traveller.)
If you want to submit an adventure (in any form), then just use the contact form in the Contact Page and you will be contacted. Fan fiction for Traveller or something Science Fiction related will also be fine.