The U.S. Defense Department on Oct. 27 selected Northrop Grumman to build a new strategic bomber fleet. Between 80 and 100 planes are expected to be produced over the next decade. But three important questions must be answered before Congress approves significant funds for the program.

First, what will the bombers actually cost? The air force claims it can build 100 for no more than $564 million each. But even if that were true, the price tag does not include the development costs, estimated to exceed $20 billion.

The projected costs are also in $2010 — not the actual amount taxpayers must fork over in 2017, when the planes begin to roll off the assembly line. In addition, the 2010 price assumes that there will be no cost overruns or delays — though the F-35 joint strike fighter's projected costs nearly doubled over the past 20 years it has been in development.