TABLE 4.3 Reusable Booster System Mass Breakdown to Support NASA/Air Force Cost Model Estimates
|Elements||RBD||RBS||LES||Castor 30||Star 63D|
|Weight (lb)||Weight (lb)||Weight (lb)||Weight (lb)||Weight (lb)|
|Structures and Mechanisms||14,673||60,180||22,866||246||0|
|Vehicle Structures and Mechanisms||10,271||42,567||12,742||-||-|
|Tank Structures and Mechanisms||4,402||18,243||10,124||-||-|
|Reaction Control Subsystem||303||1,143||118||74||44|
|Main Propulsion System (less engines)||1,825||9,423||3,611||-||0|
|Electrical Power and Distribution||1,697||3,876||999||222||91|
|Command, Control, and Data Handling||1,672||1,672||236||259||60|
|Guidance, Navigation, and Control||293||293||177||123||30|
|Gross Lift Off Weight (GLOW)||176,955||992,857||397,890||37,343||7,771|
|Dimensions (ft)||Dimensions (ft)||Dimensions (ft)||Dimensions (ft)||Dimensions (ft)|
|Height (landing gear up)||20.0 33.8||-||-||-|
|Height (landing gear down)||23.7 40.9||-||-||-|
a Includes 25% dry weight margin.
NOTE: LES, large expendable stage; RBD, reusable booster demonstrator; RBS, reusable booster system.
SOURCE: Air Force Space and Missile Systems Center, SMC Developmental Planning, “Reusable Booster System Costing,” presentation to the committee, February 15, 2012. Approved for Public Release.
The use varies from minimum to maximum use of manufacturing techniques such as just-in-time delivery, bar coding, robotics, commercial-off-the-shelf items, and outsourcing.
• Engineering management. This factor accounts for the variation in management approaches, from streamlined activities with minor expected changes to a widely distributed team with formalized procedures and managed interfaces. At one end of the spectrum is the assumption of a minimum number of design changes, with the design team making maximum use of the highly efficient Skunk Works approach with integrated product teams, rapid prototyping, design to cost, and the like. At the opposite end of the spectrum is the assumption of a distributed design team just waiting for major technology advances and hoping they will bring frequent major requirement and design changes.
• Design level. This factor accounts for the maturity of the vehicle design and depends on what is inherited from previous projects. A high design level value indicates that the system has little inheritance from previous projects, and vice versa. Choices for the design level range from very low values, which represent the reflight of an existing vehicle, to moderate values, which represent significant modifications to an existing design, and through high values, which represent a totally new design.
• Funding availability. This factor accounts for the potential of program development delays due to funding limitations, which create inefficiencies in execution. Choices for funding availability include these: funding is assured and no delays are expected; delays are possible but infrequent; or funding is constrained and delays are likely.
• Test approach. This factor accounts for variation in the degree of testing required during system development and reflects the amount of risk being accepted and indicated by the planned test program. Choices for test approach include minimum testing, with qualification using simulation and analysis; moderate testing, with qualification at the prototype/protoflight level; or maximum use of testing with qualification at component level.