GMAGAO-X R-01 Required contrast has not been demonstrated on-sky

[dmkelly42]

Risk creation date: 6/13/2022
Last Modified: 10/4/2022
Risk type: Technical
Risk Approach: Mitigate
Risk Owner: Doug Kelly

Risk Statement

If the contrast needed by GMAGAO-X for reflected light characterization of exoplanets cannot be achieved, GMAGAO-X will fail to meet its baseline level 1 requirement to be able to measure reflected light from Earth-like planets around nearby, Sun-like stars.

Risk Effects

In the short term, if we cannot achieve a post-processing contrast of 1E-8, we will not meet the baseline requirement of observing planets in reflected light around Sun-like stars. If we cannot achieve a post-processing contrast of 1E-7, we will be unable to pursue the threshold mission goal of observing planets in reflected light around M-type stars. Longer term, we will have to pursue measures to improve the contrast. That could mean improving in areas such as thermal stability, pointing jitter, the speed and accuracy of the wavefront measurement and phase map calculation, the speed, accuracy, or stroke of the DM corrections, and the stray light rejection of the coronagraph.

Risk Assessment:

Risk Ratings	Likelihood	Consequence
Initial	2-low	4-high
Current	2-low	4-high
Target	1-very low	4-high

Initial Risk Notes:

The WFS&C+Coronagraph system needs to provide a dark hole contrast of 1E-7 or better (L2-22), and the goal is to have a post-processed, 5-sigma contrast at 1 micron of 1E-8 or better at 6 lambda/D for stars of I<~10 mag (L2-1). These contrast levels have been achieved in the lab on MAGAO-X but have not been demonstrated on-sky.
The achieved on-sky performance is currently 1E-6. If we do no better, we would still outperform existing ground-based instruments because of having a better inner working angle. So GMagAO-X would still be an important science instrument even though it would not meet its advertised primary science goals.

Cost Impacts:

Estimated cost if risk is realized:
Explanation for cost risk:

Risk burndown and mitigation plans and status:

• Demonstrate contrast on existing instrument MagAO-X (Mitigation for R-01) #17

• Development and testing of post-processing software. Establish the data characteristics that are needed to allow significant contrast improvements in post-processing, and make sure that the instrument requirements work towards meeting these conditions.

• Modeling of coronagraphic performance (R-01 mitigation) #2

• Test bed demonstrations of various light rejection techniques, hardware, and sofware

• Optical design to incorporate an occulter that should be able to achieve the desired contrast

• Selection of DM