Structures 

Structures determine the mechanical capabilities of the vehicle.

1. Tanks 
- using fuel tanks as structure saved weight. The tank walls support the vehicle and get 
  loads at takeoff.
- Must be pressurized or they will collapse
- Made of thin walled stainless steel (single wall) the thickness of a dime
- The bottom tank supports the top tank
- Hydrazine bottle is at bottom w/ helium tank 00

2. Payload Adapter
- Structural member that payload sits on. Connects payload to the vehicle.
- Length of the adapter usually stays the same
- Diameter varies with payload
- Gives easy access to the payload
- Has a release mechanism to release the payload.

3. Equipment module
- All the accessories are listed in the avionics are mounted on here, e.g., battery, guidance, 
  computer, etc.

4. Structural Member is located on the bottom of the O2 tank. Its purpose is to take the 
   concentrated load at the small surface area of the gimbal mount and spread it out to a 
   broader area on the bottom of LOX tank.

5. Farings - take aerodynamic loads but don't take structural loads, e.g., the faring does 
   not keep the vehicle from crumbling.

The tanks take all the structural loads.
Payload faring is a synonym for shroud. The faring is made of fiber glass or aluminum.
Prelaunch - N2 warm gas is circulated in the shroud. The payload is on top of the H2 tank 
which is very cold.
Explosive charge and springs or a bottle of high pressure gas is used to separate the 
faring halves when it is time to deploy the payload.