TABLE 4.2 Basis for Reusable Booster System Flight Rate

Satellite Type Orbit Requirement EELV Used Average Annual Rate
Communications GTO Atlas V 531 0.64
Meteorological GTO Atlas V 501 0.25
SSO Delta IV M 0.32
Navigation MEO Atlas V 401 1.96
Missile warning GTO Atlas V 411 0.31
SSO Delta IV M 2.12
Intelligence LEO (high inclination) Delta IV M+(4,2) 0.20
LEO (high inclination) Delta IV H 0.29
LEO (high inclination) Atlas V 541 0.20
HEO Atlas V 551 0.29
Polar Delta IV H 0.29
Polar Atlas V 401 0.16
GTO Delta IV M+(5,4) 0.50
GEO Delta IV H 0.50
Average annual launch rate 8.00

NOTE: EELV, Evolved Expendable Launch Vehicle; GEO, geosynchronous Earth orbit; GTO, geosynchronous transfer orbit; HEO, high Earth orbit; LEO, low Earth orbit; MEO, medium Earth orbit; SSO, Sun-synchronous orbit.

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 lower-level models can identify them. All models are largely based on historical expendable vehicles and are therefore significantly handicapped by the lack of good analogous data for unmanned RBS-type reusable systems.

4.2.1 Vehicle

The vehicle estimates cover DDT&E and production costs for all flight hardware except the engines. The flight hardware includes the RBD, the RBS, and LES subsystems (less engines). Models

The NASA/Air Force Cost Model (NAFCOM)3 was used for all vehicle estimates. NAFCOM is a parametric cost estimating model based on a database of historical NASA and Air Force launch and space systems. The committee believes that NAFCOM is an appropriate tool for this application and the maturity level of the concept, although a bottoms-up cost estimating approach would further enhance credibility of the cost estimates. Inputs and Assumptions

The inputs to NAFCOM include subsystem-level masses and other system characteristics. For the baseline RBS concept, the system masses are shown in Table 4.3. The other system inputs that serve as NAFCOM inputs include factors accounting for system maturity and program management approach. The cost implications of these factors are based on historical programs. Specific input factors include the following:

Manufacturing method. This factor accounts for the identification and maturity of the manufacturing methods used in the production process and aims to address the level of use of advanced manufacturing techniques.


3 J. McAfee and G. Culver, SAIC, and M. Naderi, NASA Marshall Space Flight Center, “NAFCOM Capabilities and Results,” presentation at the 2011 Joint Army Navy NASA Air Force (JANNAF) Modeling and Simulation/Liquid Propulsion /Spacecraft Propulsion Joint Meeting, Huntsville, Al., December 5, 2011, available at

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