Science fiction RADIO script needed for charity

I work for a egistered charity called blind veterans uk. Some of our blind members miss being able to act and used to be on stage or in TV etc. What we do for them is get hold of scripts and get them to act in radio plays, due to age and poor memory and lack of sight, this is slow and painstaking, but they do it very well. You can search for the radio pla society on youtube and see what they do. We are running out of copyright free scripts and also they are getting specific about what they want to do. We are after a sci fi script that accomodates approx 3 main male and 2 main female parts with potentially some extras. We wanted something dark and a little sinister, potentially having an alien or some threat to life. Something with an isolated feel like being stuck in a ship and possibly some tension between characters. Ideally around 25-45 minutes. Our budget is super low, but we do not sell or broadcast for commercial gain, so might suit somebody who already has a script and wants to test it or something along those lines. Thank you for your time.