Ho! Ho! Ho! (13 pages, free at DriveThruRPG) is a fun sci-fi adventure for Cepheus Engine RPG, but I used Comae Engine (45 pages, same place). To create my solo engine, I changed four lines in Rocket Rangers (T.W.E.R.P.S.) by GameScience (12 pages). I used eight first level characters.

So, the mission was to deliver toys to five different worlds. The PCs had to deal with meteor showers, ion storms, and active volcanoes. One dangerous challenge was a pirate ship. Within a few minutes, the PC ship was out of control (going in a straight line). The AutoPilot, Pilot Couch, and Pilot had been destroyed. The pirate ship lost its Faster Than Light Travel. The AutoNavigator, Navigational Couch, and Navigator had been destroyed. The battle ended, and both sides worked on repairs. While on a world with tribal hostility, the main antagonist (Grrr) pretended to be a baggage handler. He was going to destroy the toys. The alien mystic PC noticed him, did a detect thought, followed with a charm person (the second spell failed). Grrr signaled his ship and it fired at the PCs on the ground. My security PCs fired back and killed him. The Grrr ship hovered in place, the authorities arrived, the Grrr ship was confiscated, and the PCs were questioned. The PCs did get released. They did get a nice reward for completing their mission on time. Give this free adventure a try!