First, a small clarification - Red Peri is a female pirate captain, her ship is the Red Peri.
Adventure Idea: Frozen Fortress
For decades the pirate Red Peri operated from a base on Pluto, but the secret was revealed when a prisoner escaped. It will be years before the authorities can reach her there, but engines are improving and she’s looking at alternatives. One is the dark side of Mercury. Her equipment is designed for cold conditions; the main problems are a distinct lack of air and water. And there may be a way to arrange that; steer a comet to the dark side, where it will crash, melt, and freeze. After that melt the ice and electrolyze the water to release its oxygen.
In a few months a "sun-grazing" comet will pass within half a million miles of Earth, heading back towards the outer Solar System. Attorneys for the mysterious Rip Reed Foundation (an anagram of Red Peri; Rip Reed is supposed to be a reclusive millionaire) hire the adventurers to fly to the comet, land, survey it, take specimens from the surface and core samples, and bring them back to Earth. They’re told that Reed hopes to find evidence of the composition of the primordial Solar System in the dissolved gasses and other materials of the comet. In fact the real purpose of the mission is to find out if there’s enough water in a comet to make the scheme worth trying, and if a comet is strong enough to withstand the forces that would be needed to push it into the right orbit for a "gentle" impact.
The main complication is that getting to the comet will take a lot of power – it’s moving fast. Flying there then decelerating, landing, and heading straight back to Earth would take more fuel and supplies than the adventurers’ ship can carry; it will be easier to head on to Mars and refuel before heading back to Earth. The attorneys "reluctantly" agree to the additional expense and time. As instructed, of course.
There should also be a few complications on the comet; perhaps there is some sort of life there, perhaps there is evidence of a previous landing by non-humans such as the early Martians, perhaps it’s just accompanied by hundreds of icy meteors. But the adventurers should feel pleased with their success as they prepare to land on Mars.
Unfortunately, their ship will then be attacked by the Red Peri, and all records and samples will be taken. "Luckily" the Foundation insured the mission, and in the end the adventurers won’t lose much apart from time and their place in scientific history (assuming that there had ever been a real intention to publish their results). Working out who really hired them and why should lead to some interesting adventures.
This really needs a better title - any suggestions?