The Large UV/Optical/IR Surveyor (LUVOIR) is a concept for a highly capable, multi-wavelength observatory with ambitious science goals. This mission would enable a great leap forward in a broad range of astrophysics, from the epoch of reionization, through galaxy formation and evolution, to star and planet formation. LUVOIR also has the major goal of characterizing a wide range of exoplanets, including those that might be habitable—or even inhabited.
LUVOIR is one of four Decadal Survey Mission Concept Studies initiated in January 2016. The study will extend over three years and be will executed by the Goddard Space Flight Center, under the leadership of a Science and Technology Definition Team (STDT) drawn from the community.
More information may be found on the LUVOIR website.
A white paper reporting the results of this RFI ia available [PDF]
Recommended by the 2010 "New Worlds, New Horizons in Astronomy and Astrophysics" report, a UV/Optical telescope as a successot to HST is being studied. The instrumentation being considered includes high-efficiency UV and optical cameras / spectrographs operating at shorter wavelengths than HST, with the possibility of internal coronagraphs or external star-shades. NASA's Cosmic Origins Program is investing in essential technologies such as detectors, coatings, and optics, to prepare for a mission to be considered by the 2020 decadal survey.
The Hubble Space Telescope is in a decaying orbit that will cause an uncontrolled re-entry in around 2025. To prevent the hazards created by such an event, the Cosmic Origins Program Office has undertaken a study of a mission to dispose of the great observatory, either by controlled re-entry or placement into a long life orbit.
SPICA is a Japanese-led proposed infrared space telescope, successor of the successful AKARI spacecraft. This mission seeks to take the next step in investigating the mid (> 5 micrometers) through far (400 micrometers) infrared portion of the spectrum to observe many astrophysical phenomena from distant galaxies to star and planet forming systems in our own Galaxy.
This science was highly ranked by the "New Worlds, New Horizons 2010 Decadal Study in Astronomy & Astrophysics," and possible NASA involvement was recommended. Budget pressures have precluded such involvement, so the Cosmic Origins Program is investing in relevant technology development, and is investigating other ways to pursue the high priority science goals.