This list contains proposals for space telescopes, space-based (situated in space) astronomical observatories. It is a list of past and present space observatory plans, concepts, and proposals. For observatories in orbit, see list of space telescopes. Unlike that list, this one includes concepts and proposals that are unlikely ever to be launched, as they may have been cancelled or were only proposals.
Name | Agency | Type | Proposed launch date |
Status | Proposed location | Ref(s) |
---|---|---|---|---|---|---|
X-ray Polarimeter Satellite (XPoSat) | ISRO/RRI | X-Ray | Q2 2023 | under construction | Low Earth orbit | [1][2] |
SVOM | CNSA/CNES | X-Ray | March 2024 | under construction | Low Earth orbit | [3][4] |
TOLIMAN | NASA | visible | 2024 | Proposal | Low Earth orbit | [5] |
Xuntian | CNSA | ultraviolet, visible, infrared | 2024 | under construction | Low Earth orbit | [6][7] |
PLATO | ESA | visible | 2026 | Under construction | Sun-Earth L2 Lagrange point | |
Nancy Grace Roman Space Telescope (formerly WFIRST) | NASA | infrared | 2026-2027 | confirmed and named 2020 | Sun-Earth L2 Lagrange point | [8][9] |
LiteBIRD | JAXA | millimeter radio | 2028 | Approved for development | Sun-Earth L2 Lagrange point | [10] |
Spektr-UV (WSO-UV) | Roscosmos | ultraviolet | 2028 | funded | Geosynchronous orbit | [11] |
Laser Interferometer Space Antenna (LISA) | ESA/NASA | gravitational waves | 2037 | Solar Earth-trailing orbit (approx. 1 AU) | [12] | |
Astrosat-2 | ISRO | Near Ultraviolet, Far Ultraviolet, Visible | TBD | – | Low Earth orbit | [13] |
Habitable Worlds Observatory (HWO) | NASA | Ultraviolet, Visible, Infrared | 2041 | early planning 'Phase 1' | Sun-Earth L2 Lagrange point | |
X-Ray Great Observatory (nicknamed Fire) | NASA | X-Ray | 2047 | early planning 'Phase 1' | possibly Sun-Earth L2 Lagrange point | |
Far-Infrared Great Observatory (nicknamed Smoke) | NASA | Far-Infrared | 2051 | early planning 'Phase 1' | possibly Sun-Earth L2 Lagrange point |
Name | Agency | Type | Proposed launch date |
Status | Proposed location | Ref(s) |
---|---|---|---|---|---|---|
X-Ray Evolving Universe Spectroscopy Mission (XEUS) | ESA | X-ray | Merged into IXO | – | [15] | |
Constellation-X | NASA | X-ray | – | |||
International X-ray Observatory (IXO) | NASA & ESA & JAXA | X-ray | No funding 2011; rebooted as ATHENA | – | [16] | |
Exoplanetary Circumstellar Environments and Disk Explorer (EXCEDE) | NASA | ? | 2016 | – | Sun-synchronous Earth orbit, 2000 km | [17][18] |
SIM Lite Astrometric Observatory | NASA | ? | 2015 | No funding 2010 | – | [19] |
Darwin Mission | ESA | ? | – | – | Sun-Earth L2 Lagrange point | [20] |
Terrestrial Planet Finder | NASA | ? | TBA | No funding 2011 | – | [21] |
Dark Universe Observatory | NASA | ? | Superseded by Roman/WFIRST | Earth orbit (600 km) | [22][23] | |
Joint Dark Energy Mission | NASA & DOE | ? | – | [24] | ||
Astromag Free-Flyer (Particles) | NASA | ? | 1 January 2005 | – | Earth orbit (500 km) | [25][26] |
VSOP-2 (Astro-G) (Radio) | JAXA | ? | 2012 | Cancelled 2011 | – | [27] |
SAFIR | NASA | far infrared | Superseded by Origins | Sun-Earth L2 Lagrange point | ref? |
For launch in the 2030s, NASA is evaluating four possible designs: the Origins Space Telescope, Lynx X-ray Surveyor, Habitable Exoplanet Imaging Mission (HabEx), and Large UV Optical Infrared Surveyor (LUVOIR).[28]
Balloon-borne telescopes have been in use since the 1950s. A 20–30 meter balloon telescope has been suggested.[29] The balloon would be transparent on one side, and have a circular reflecting mirror on the other side.[29] There are two main designs using this principle.[29]