 His work focuses on determining, observationally, the relationships between galaxy-scale phenomena and the surrounding large-scale environment and matter distribution.Marc Postman served on several science working groups exploring the capabilities of future large optical / near infrared telescopes on the ground and in space.He is the Principal Investigator for a NASA Strategic Mission Concept Study called the Advanced Technology Large-Aperture Space Telescope, a possible successor to the Hubble Space Telescope.