Critical Technologies Maturation and Evaluation of Pathfinder Architecture for Habitable Worlds Observatory

In 2021, following promising feasibility studies led by NASA, the National Academies in the Decadal Survey on Astronomy and Astrophysics officially recommended a flagship mission to search for the existence of life outside of our solar system. In response, NASA in partnership with the astrophysics community and with support from industry is currently performing architecture studies and advancing critical technologies for the Habitable Worlds Observatory (HWO), a next generation large space observatory capable of directly imaging and characterizing Earth-like exo-planets in the habitable zone of nearby stars. HWO uses a coronagraph to block the light of the parent star and demands unprecedented levels of wavefront stability on the order of 10 picometers over
long time scales to achieve the raw contrast ratio of better than 10-10 and the contrast stability of 10-12 necessary for direct exo-Earth imaging.

In this article, we report on Lockheed Martin team’s progress advancing four critical technologies for HWO covering vibration isolation and precision pointing systems, picometer-class metrology, structural damping augmentation, and cryogenic detector cooling. We also report on our evaluation of the dynamic line-of-sight and dynamic wavefront error stability achieved during science observation and following large angle slews using Lockheed Martin’s Disturbance Free Payload (DFP) system for vibration isolation from the host spacecraft to the telescope on a pathfinder observatory architecture developed by NASA and its partners called Exploratory Analytical Case 1. The optical telescope assembly in that case consists of an off-axis 6-meter inscribed-diameter segmented primary mirror with 19 segments and an unobscured telescope.

Our approach to achieving the requisite dynamic wavefront stability with DFP consists in flying the optical telescope assembly and the host spacecraft in close formation. In that architecture, the telescope is mechanically disconnected from the spacecraft aside from harnesses bridging that interface, thereby providing superior levels of vibration isolation. DFP enables high science observation efficiencies with little-to-no downtime following slews and enables tight telescope attitude control at ~0.6-Hz bandwidth.

We discuss our study findings to-date and the implications for the design of the observatory and its active wavefront sensing and control system.