Telescope for Habitable Exoplanets and Interstellar/Intergalactic Astronomy

Telescope for Habitable Exoplanets and Interstellar/Intergalactic Astronomy (THEIA) is a NASA-proposed 4-metre optical/ultraviolet space telescope that would succeed the Hubble Space Telescope and complement the infrared-James Webb Space Telescope. THEIA would use a 40-metre occulter to block starlight so as to directly image exoplanets.

It was proposed with three main instruments and an occulter:{{Cite web |url=https://www.princeton.edu/~hcil/papers/theiaWhitePaper.pdf |title=Archived copy |access-date=2015-10-30 |archive-date=2016-11-27 |archive-url=https://web.archive.org/web/20161127023945/https://www.princeton.edu/~hcil/papers/theiaWhitePaper.pdf |url-status=dead }}

• eXoPlanet Characterizer (XPC)
• Star Formation Camera (SFC),
• Ultraviolet Spectrograph (UVS)
• A separate occulter spacecraft