Estimate the mission beyond launch day

A mission can incur costs for concept studies, design, fabrication, testing, launch, ground systems, operations, analysis and closeout. Which items appear in a published total depends on its accounting boundary. A low quoted spacecraft price is not necessarily a low complete mission cost.

A life-cycle estimate connects costs to a technical description and schedule. If the scope changes, the estimate needs to change with it. A reserve is intended to address uncertainty within a defined plan; it should not be mistaken for proof that every possible future problem has already been priced exactly.

Suppose fictional option A costs 60 units to develop and 8 per year to operate for five years. Its simplified total is 100 units. Option B costs 80 to develop and 3 per year for five years, totaling 95. The lower development price does not produce the lower five-year total in this example.

These classroom totals omit discounting, uncertainty and any costs not stated, such as launch or closeout. A real decision would need those boundaries made explicit. The arithmetic illustrates why a fair comparison must use the same duration, delivered capability and included cost categories.

Compare equal life-cycle boundaries

Schedule changes can affect staffing, facilities, storage and other costs. Technical uncertainty can alter the amount of redesign or testing required. Sensitivity analysis — open definition examines how an estimate changes when important assumptions change; it is more informative than displaying many decimal places without a defensible basis.

A review should preserve the original baseline and explain later changes. A revised scope can make a simple before-and-after total misleading unless the capabilities are compared too. The useful question is not merely whether a number rose, but what changed, why it changed and how much uncertainty remains in the current estimate.