9.45 category (R&D, procurement, refurbishment), and the individual costs are charged at a constant rate over the period during which it is applicable.· In this way, yearly cash flow is found. At the end of year 16, the yearly totals may be added up to find the total cost for the colony development and construction program: $64.5 billion. However, this is not the total price which must be considered in making the program go-ahead decision. The U.S. Office of Management and Budget also assesses an interest charge to the money used, to find the total costs, including those costs associated with the loss of revenue created by tying up the money over the length of time of the program. Standard rates for aerospace projects have been set at 10%, compounded yearly. Using this interest rate, then, over the 16 year program time, and discounting the yearly running total at this 10%, the total discounted program costs at the end of year 16 is $147.7 billion. To put this into perspective, the price usually quoted for a mission to Mars, similarly discounted, is $100 billion. Figure 9.11 shows the yearly expenditures, and Figure 9.12 shows undiscounted and discounted cumulative costs.
RkJQdWJsaXNoZXIy MTU5NjU0Mg==