The rest of this section will list some possible ways NASA could address the different application areas using space and aeronautics. For the sake of discussion, two scenarios are considered. In the first scenario, the Constellation program is removed entirely, and budgets are allocated and adjusted in such a way that roughly $7 billion dollars is made available to this new NASA application emphasis by the Constellation cancellation and Shuttle retirement. This amount is divided equally for 8 application areas to allow a discussion of what types of things might be accomplished with about $900M per year budgets for these 8 application areas.
In the second scenario, the Constellation program survives, but is restricted to a smaller, less ambitious transportation system that simply transports a minimal crew of 2 to Low Earth Orbit destinations. This transportation system is developed on a stretched-out schedule. This restriction results in $4 billion per year for the application areas upon Shuttle retirement, or $500 million per year each if evenly divided.
These figures are just conceptual examples to illustrate the types of things that could be done as an alternative to Constellation. They are illustrations of the concept of “opportunity cost”, a concept that may be particularly relevant to the Constellation architecture. The particular scenarios are unlikely to happen, but the point is valid whether the actual budget for a particular new application area is $100 million per year or $2 billion per year.