Let's start with the characters. They are not newbies. They have survived the events of Volturnus modules. To that end, they are in advanced officer training and learning to crew a spaceship.
In my campaigns, spaceship skills are selectable from the get-go. These characters have 20 experience points for anything they like from the Alpha Dawn set and 10 experience points to spend on one spaceship skills. The players have one special option at character generation - they can trade 1 exp point for 1,000 credits. This pairs nicely with the 20 exp for any AD skill. The characters will be nicely equipped with the expectation everyone has one or more guns.
I don't believe in yanking the character's equipment at the start of the adventure.
Next, the characters have a home base, a planet named Typhon. It's a water world with underwater living quarters. The population is small, but growing after the war. The planet features a chain of islands around the equator. There are many aquatic animals in the planetary ocean and more than a few amphibians inhabiting the island. Even the bird and rat-like creatures are amphibians. It is an interesting world without too much excitement. Typhon is one of those "best-kept secrets" planets, beautiful and safe, not well known yet and not completely explored.
Also in the Typhon system is the planet Dust. This planet is barely habitable, but the low-oxygen atmosphere is great for storing and repairing spaceships. It is a base for training future astronauts. It isn't as dangerous as training in a vacuum. All species hate the environment, it requires suits for comfort but you can survive on the surface. Just barely. Typical stints on Dust last between a month and 3 months. The planet has one main base and dozens of smaller bases scattered here and there.
If you weren't learning how to be an astronaut, you'd have no reason to visit and even less to stay. Everyone, including the general staff, tries to speed run any necessary tasks to get back to the comfort of Typhon. Failing that, a tiny ship and a hard vacuum would do.
Now we are to the meat of the setting. There has been a rash of incidents where the visitors to Dust go missing. They vanish after leaving Dust for other destinations. This is bizarre because they spend some time at the destination getting settled, checking in with friends and family, and getting spotted on plenty of security cameras. Then they are gone. The one commonality is they disappear at night. No bodies have been found, no ransom remains, there is no pattern to the destinations, and no foul play is evidenced but is obviously suspected.
Since the Sathar and their agents have been sent packing, it is an interplanetary locked room mystery for the players to solve.
At DriveThruRPG
I picked up the print copy of AD from DriveThruRPG. The printing is excellent, the binding looks sharp and clean.