Habitable Worlds Observatory

The Habitable Worlds Observatory (HWO) is a large infrared, optical, and ultraviolet space telescope recommended by the National Academies’ Decadal Survey on Astronomy and Astrophysics 2020. It will be optimized to search for and image Earth-size habitable exoplanets in the habitable zones of their stars, where liquid water can exist, by using a coronagraph to block out the light of their stars, as well as provide broad astrophysics observations. HWO builds upon studies conducted for two earlier mission concepts called the Large Ultraviolet Optical Infrared Surveyor (LUVOIR) and Habitable Exoplanets Observatory (HabEx).

Mission Goals
HWO’s main objective would be to identify and directly image at least 25 potentially habitable worlds. It would then use spectroscopy to search for chemical biosignatures in these planets’ atmospheres, including gases such as oxygen and methane which could serve as critical evidence for life. HWO would also use its high sensitivity and resolution capabilities to trace the evolution of galaxies and other cosmic structures.

The main science themes for HWO are:


 * Drivers of Galaxy Growth
 * Evolution of Elements Over Cosmic Time
 * Solar System in Its Galactic Context
 * Living Worlds

Development
In 2023, the National Aeronautics and Space Administration (NASA) established a Great Observatory Maturation Program (GOMAP) to unite government, industry, and academia to develop the technologies needed for HWO. GOMAP aims to draw on lessons from previous NASA missions to streamline development of the HWO concept and decrease budget and schedule risks for the future mission.

Two groups will guide the GOMAP activities for HWO: a Science, Technology, Architecture Review Team (START) and a Technical Assessment Group (TAG). The START will quantify HWO’s science objectives based on the Decadal Survey’s guidance and outline the observatory and instrument capabilities needed to accomplish them. Meanwhile, the TAG will study architecture options for HWO, identify and assess the mission architectures and technologies needed to enable those options, and evaluate the risks associated with those options.

The HWO is designed to be launched on a super heavy-lift launch vehicle. The HWO's team hope for the success of big launchers such as SpaceX's Starship, Blue Origin's New Glenn or the SLS due to their critical importance to the HWO's mission. The HWO is planned have a 6-8 meter mirror for now, but its design should be flexible to leverage launchers with potentially double the mass and volume by the time the HWO launches in the 2040s. Lee Feinberg, NASA HWO lead architect and JWST manager, stays in communication with the three launchers' representatives. In 2024, he visited SpaceX to track Starship's progress. Former NASA JPL architect Casey Handmer believes the HWO to be far too conservative compared to what is possible with Starship. Handmer argues that Starship enables telescopes to scale up to the point of surface-level exoplanet imaging, perhaps big enough to detect seasonal migration patterns.