Wide Field Infrared Survey Telescope
Rendered model of the WFIRST spacecraft
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| Names | Joint Dark Energy Mission |
|---|---|
| Mission type | Infrared Space observatory |
| Operator | NASA / JPL / GSFC |
| Website | wfirst |
| Mission duration | 6 years (planned) |
| Spacecraft properties | |
| Launch mass | 4,166 kg (9,184 lb) |
| Dry mass | 4,059 kg (8,949 lb) |
| Payload mass | 2,191 kg (4,830 lb) |
| Power | 2500 watts |
| Start of mission | |
| Launch date | Mid-2020s |
| Rocket | Delta IV Heavy (proposed) |
| Contractor | United Launch Alliance (proposed) |
| Orbital parameters | |
| Reference system | Sun–Earth L2 |
| Regime | Halo orbit |
| Periapsis | 188,420 km (117,080 mi) |
| Apoapsis | 806,756 km (501,295 mi) |
| Main telescope | |
| Type | Three-mirror anastigmat |
| Diameter | 2.4 m (7 ft 10 in) |
| Wavelengths | Near-infrared, visible light |
| Transponders | |
| Band |
S band (TT&C support) Ka band (data acquisition) |
| Bandwidth | Few kbit/s duplex (S band) 290 Mbit/s (Ka band) |
| Instruments | |
| Coronagraph Instrument Wide Field Instrument |
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The Wide Field Infrared Survey Telescope (WFIRST) is a future infrared space observatory that was recommended in 2010 by United States National Research Council Decadal Survey committee as the top priority for the next decade of astronomy. On February 17, 2016, WFIRST was formally designated as a mission by NASA.
WFIRST is based on an existing 2.4m wide field-of-view telescope and will carry two scientific instruments. The Wide-Field Instrument is a 288-megapixel multi-band near-infrared camera, providing a sharpness of images comparable to that achieved by the Hubble Space Telescope over 100 times the area. The Coronagraphic Instrument is a high contrast small field of view camera and spectrometer covering visible and near-infrared wavelengths using novel starlight-suppression technology.
The design of WFIRST is based on one of the proposed designs for the Joint Dark Energy Mission between NASA and DOE. WFIRST adds some extra capabilities to the original JDEM proposal, including a search for extra-solar planets using gravitational microlensing. In its present incarnation (2015), a large fraction of its primary mission will be focused on probing the expansion history of the Universe and the growth of cosmic structure with multiple methods in overlapping redshift ranges, with the goal of precisely measuring the effects of dark energy, the consistency of General Relativity, and the curvature of spacetime.
The original design of WFIRST (Design Reference Mission 1), studied in 2011–2012, featured a 1.3 m (4 ft 3 in) diameter unobstructed three-mirror anastigmat telescope. It contained a single instrument, a visible to near-infrared imager/slitless prism spectrometer. In 2012, another possibility emerged: NASA could use a second-hand National Reconnaissance Office telescope made by Harris Corporation to accomplish a mission like the one planned for WFIRST. NRO offered to donate two telescopes, the same size as the Hubble Space Telescope but with a shorter focal length and hence a wider field of view. This provided important political momentum to the project, even though the telescope represents only a modest fraction of the cost of the mission and the boundary conditions from the NRO design may push the total cost over that of a fresh design. This mission concept, called WFIRST-AFTA (Astrophysics Focused Telescope Assets), was matured by a scientific and technical team; this mission is now the only present NASA plan for the use of the NRO telescopes. The WFIRST baseline design includes a coronagraph to enable the direct imaging of exoplanets.
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