At first thought the idea of co-op in a franchise like Dead Space is a horrible idea as it would ruin the suspense and fear of being alone in the dark corridors fighting off the hordes of "nekkies." Resident Evil tried it and it was no longer scary. But your idea about the co-op partner being separated on their own missions and you both working towards common goals helping each other out and occasionally meeting up sounds AWESOME! I think that would be the only way to do it and keep the fear factor intact.
At first thought the idea of co-op in a franchise like Dead Space is a horrible idea as it would ruin the suspense and fear of being alone in the dark corridors fighting off the hordes of "nekkies." Resident Evil tried it and it was no longer scary. But your idea about the co-op partner being separated on their own missions and you both working towards common goals helping each other out and occasionally meeting up sounds AWESOME! I think that would be the only way to do it and keep the fear factor intact.