WSO-UV is a multipurpose observatory, made by a 170 cm aperture telescope, capable of high-resolution spectroscopy, long slit low-resolution spectroscopy, and deep UV and optical imaging. With a nominal mission life time of 5 years, and a planned extension to 10 years, from a geosynchronous orbit, WSO-UV will provide observations of exceptional importance for investigating several astrophysical problems. WSO-UV is equipped with multipurpose instrumentation to carry out:

• High resolution spectroscopy (R~55,000) of point sources in the range 1020–3100A by means of two high resolution echelle set-ups: HIgh Resolution Double Echelle Spectrograph (HIRDES) . The sensitivity of this instrument is about ten times better that of the Space Telescope Imaging Spectrograph (STIS) on a similar configuration.
• Long-slit low resolution spectroscopy (R~1500) in the 1020-3200 A range with the Long Slit Spectrograph (LSS).
• Imaging and slit-less spectroscopy (R~500) in the 1200-2000 A range with spatial resolution 0.05 arcsec and field of view 2 arcmin for weak UV sources with the High Sensitivity Channel (HSC) of the Imaging and Slitless Spectrograph Instrument for Surveys (ISSIS)
• Imaging and slit-less spectroscopy (R~500) in the 1200-7000 A range of large fields of view (>2x2) for surveys, with spatial resolution 0.05 arcsec ( difraction limited at 340nm) with the Channel for Surveys (CfS) of the Imaging and Slitless Spectrograph Instrument for Surveys (ISSIS)

OPTICAL BENCH:

The WSO-UV telescope provides an accessible field of view of 30 arcmin on the telescope focal plane. The Instrumental Compartment consists of the (serially connected to each other) cylindrical insert (3) and thermostabilised protective cover (4) made of aluminum alloy. The IC insert is attached to the supporting frame of the Telescope PMU at 3 points. The IC thermal protective cover is attached to the bottom of the IC insert flange. The insert has been made the loading bearing structure. The Telescope loading is transferred to the transitional truss of the Navigator Service.

The optical bench (OB), used as reference plane for all the onboard instrumentation, is aligned and maintained in the correct position with respect to the primary mirror unit (PMU) using a three rods system. The ISSIS is mounted on the upper basis of the optical bench, in the space available between the PMUa nd the OB itself, while the three spectrographs UVES, VUVES and LSS are mounted to the OB bottom basis. The Fine Guidance System, that uses three visible sensors placed at the vertex of an equilater triangle in the focal plane close to the spectrograph entrance slits, ensures a pointing stability better than 0.03 arcsec (1 sigma). Each of the focal science plane instruments has its own power supply and data handling unit in a service box mounted on the external side of the instrument compartment.

General view of the Focal Assembly (scientific instruments mounted on the OB) is shown in image below.