Wide Field Camera 3

The Wide Field Camera 3 (WFC3) will be the Hubble Space Telescope's (Hubble) last and most technologically advanced instrument to take images in the visible spectrum. It is scheduled to be installed in 2008 during STS-125. STS-125 is currently scheduled by NASA to launch on 14 October 2008.

pecifications

The instrument is designed to be a versatile camera capable of imaging astronomical targets over a very wide wavelength range and with a large field of view. It is a fourth-generation axial instrument for Hubble. The instrument has two independent light paths: an optical channel which uses a pair of charge-coupled devices (CCD) to record images from 200 nm to 1000 nm; and a near infrared detector array that covers the wavelength range from 800 to 1700 nm. Both channels have a variety of broad and narrow-band filters, as well as prisms and grisms, which enable wide-field, very-low-resolution spectroscopy that is useful for surveys. The optical channel covers the visible spectrum (380 nm to 780 nm) with high efficiency, and is also able to see into the near ultraviolet (down to 200 nm).

WFC3 features two UV/visible detecting CCDs, each 2048x4096 pixels, and a separate IR CCD of 1024 x 1024, capable of receiving infrared radiation up to 1700 nm.

Both detector focal planes were designed specifically for this camera. The optical channel covers a 164 by 164 arcsec (2.7 by 2.7 arcminute, about 8.5% of the diameter of the full moon) field of view with 0.04 arcsec pixels. This field of view is comparable to the Wide Field and Planetary Camera 2 and is slightly smaller than the Advanced Camera for Surveys. The near infrared channel has a field of view of 135 by 127 arcsec (2.3 by 2.1 arcminutes) with 0.13 arcsec pixels, and has a much larger field of view than Near Infrared Camera and Multi-Object Spectrometer, which it is designed to largely replace. The near infrared channel is a pathfinder for the future James Webb Space Telescope.

The camera makes use of returned space hardware as the structure is built from the original Wide Field and Planetary Camera as well as the filter assembly. It was originally conceived as an optical channel; the near infrared channel was added later. WFC3 is intended to ensure that Hubble retains a powerful imaging capability through to the end of Hubble's lifetime.

History

WFC3 has been in the planning since the Spring of 1998. It is being built by a team of highly-experienced Hubble engineers and scientists drawn from many organizations, with leadership at Goddard Space Flight Center in Maryland. WFC3 is being constructed mostly at Goddard Space Flight Center and Ball Aerospace in Colorado. Various parts are being built by contractors across the United States and the United Kingdom.

ee also

*Wide Field and Planetary Camera
*Wide Field and Planetary Camera 2
*Cosmic Origins Spectrograph
*Advanced Camera for Surveys
*Near Infrared Camera and Multi-Object Spectrometer
*Faint Object Camera

As of April 5, 2008, the instrument is in ThermalVac test at GSFC, Building 10.

External links

* the [http://www.stsci.edu/hst/wfc3 WFC3 Web site] at the [http://www.stsci.edu Space Telescope Science Institute] , which includes a description of the instrument and a link which compares the fields of view for various Hubble cameras.
* [http://www.nasa.gov/mission_pages/hubble/team/index.html Hubble Space Telescope Team]
* [http://www.stsci.edu/hst/wfc3/design/images/hst-detectors-sm4.html Hubble instrument comparisons]