Kevin P. Thompson, Tobias Schmid, and Jannick P. Rolland
The next major space-borne observatory, the James Webb Space Telescope, will be a 6.6M field-biased, obscured, three-mirror anastigmat (TMA). Over the used field of view, the performance of TMA telescopes is dominated by 3rd order misalignment aberrations. Here it is shown that two dominant 3rd order misalignment aberrations arise for any TMA telescope. One aberration, field constant 3rd order coma is a well known misalignment aberration commonly seen in two-mirror Ritchey Chretien telescopes. The second aberration, field-asymmetric, field-linear, 3rdorder astigmatism is a new and unique image orientation dependence with field derived here for the first time using nodal aberration theory.