In December 2013, NASA announced the selection of the Occulting Mask Coronagraph (OMC) as the primary architecture for the WFIRST/AFTA coronagraph instrument. OMC is a point design that is convertible between Shaped Pupil Coronagraph (SPC) and Hybrid Lyot Coronagraph (HLC) modes of operation. NASA set the objective of maturing the WFIRST/AFTA coronagraph to Technology Readiness Level (TRL) 5 by 9/30/2016. To this end, a technology development plan was drafted and approved that defined 9 milestones in fiscal years 2014-2016 that marked significant accomplishments on the path toward reaching TRL-5. The first key milestone was worded as:

The Shaped Pupil Coronagraph (SPC) is a high-contrast imaging system pioneered at Princeton and designed for the TPF-C telescope. In this document, we summarize the work done to date on the SPC to date and evaluate its current and projected performance. What makes the SPC attractive for TPF is that it is very simple to make and set up, and it is inherently broadband. Owing to the simplicity of the SPC, it is quickly becoming a relatively mature technology with theoretical and experimental validations of its performance. Many shaped pupils have been designed to various specifications and tools are in place to quickly turn out more. Full vector-field simulations show that realistic shaped pupils can already achieve 1010 contrast in the absence of aberrations. A manufacturing process has been developed to make shaped pupils for as little as a few thousand dollars, at JPL and NIST. Shaped pupils have also been shown to be very insensitive to aberrations, and especially low order aberrations such as tilt and defocus. The SPC is undergoing extensive studies in the lab, and so far a suppression of 4 × 10-8 has been achieved in 10% broadband light (averaged across a region between 4 and 9 λ/D), after speckle-nulling-based wavefront correction. The limiting factor is now believed to be well-understood and is primarily the inability of the speckle nulling algorithm to correct for manufacturing errors in the mask. It was shown that this limitation can be overcome by using a more sophisticated estimation algorithm called peak-a- boo, or by using a shaped pupil design that is insensitive to manufacturing defects. The SPC lends itself well to many wavefront estimation and correction schemes. Simulations show that realistic shaped pupil manufacturing errors and realistic wavefront error can be corrected with a single DM at one wavelength, and 2 or 3 DMs in broadband. The main disadvantages of the SPC is throughput, sharpness, and working angle, but the throughput disadvantage may be counterbalanced to an extent by the fact that SPC requires very few optical components and the fact that the light blocked by the mask may still be used to sense aberrations.