In Mission 30 the player recovers the shuttle, and docks it at STA. The shuttle can't re-enter HOM because of damaged heat shields. This post discuss an idea for how that could be fixed and we can bring the shuttle home as well as add a new feature.
The shuttle would come in two parts: the boosters plus fuel tank, and the orbiter itself.
Splitting up the shuttle from the boosters and fuel tank would also allow for an Energia style vehicle to be constructed. The Energia could reuse the same booster and fuel tank part, but would have a separate one time use rocket that could carry a medium payload instead of the shuttle.
After the shuttle is placed on the external tank and booster combination, the player can load up the shuttle with supplies. A small sized payload can also be placed in the open cargo bay.
The orbiter would be launched in a side profile view, with the fuel tank and boosters on the right and the orbiter on the left. This keeps the view consistent across all of the modes of operation.The launch tower would be displayed behind the vehicle instead of the the left.
The orbiter would follow the same pattern as other rockets of pitching over to the right during launch. This places the orbiter on top of the external fuel tank, which is different from real life launches. This difference is important because it sets up the orbiter in the correct orientation for re-entry with the heat shield facing down.
The shuttle movement would operate similar to other vehicles. There is one additional button to support a unique feature of the orbiter.
The button controls the cargo bay doors. The cargo bay can be opened using a special button in the interface. Once the cargo bay is open, if the cargo inside free floating. The shuttle can be maneuvered away from the object to have it exit the cargo bay.
Shuttle on the left with cargo bay doors closed. Shuttle on the right with cargo bay doors open and a station module shown inside
The cargo bay can also be used to capture existing objects and return them to HOM. The shuttle can maneuver so that the object enters the empty cargo bay, and then the cargo bay doors can be closed around the object (assuming that the object would fit). This secures the object in the cargo bay.
This cargo bay system is simple and can work with any cargo that will fit, including those that don't have a docking port.
The existing shuttle design works in space, but it just doesn't feel right for re-entry because of the position of the heat shield. In other vehicles, the heat shield is positioned along one edge of the vehicle and this is edge of the vehicle that enters the atmosphere facing down. The current shuttle is different, the heat shield is actually underneath and not really shown, so there is no way to position the vehicle with it facing down. This can be fixed if the shuttle is shown in profile view instead of top down view.
The shuttle would re-enter similar to other vehicles. The nose of the shuttle would be toward the right side of the screen, in the same orientation as in orbit. The shuttle would tilt backwards and forwards due to turbulence. As it descends through the atmosphere, the goal would be to keep it level using thrusters.
Once the shuttle reaches a low enough altitude the landing gear can be deployed (instead of a parachute). Then a cut scene would take over and show the shuttle landing on a runway. A successful landing of the shuttle in sandbox mode awards the player one quick launch.
Mission 30 could be modified to use the new shuttle design with little impact. Both designs have a docking port on one side of the vehicle.
Big thanks to Chris @ York Space Agency for letting me bounce some of these ideas off of him.