Survey of cost models for space telescopes

Parametric cost models are routinely used to plan missions, compare concepts, and justify technology investments. However, great care is required. There is a lot of confusion and wrong information for space telescopes. Cost estimating relationships based on primary mirror diameter vary by an order of magnitude. Cost estimating relationships based only on mass lack sufficient detail to support concept analysis and can lead to inaccurate conclusions by encouraging excessively complex and technologically immature solutions. Similarly, using ground-based models leads to incorrect conclusions. This work surveys current and historical published cost models for space telescopes while attempting to interpret them in a common logical framework to enable a systematic intercomparison.