The Multi-Application Solar Telescope (MAST) is a 50 cm diameter class telescope to be installed by AMOS on the
Udaipur Solar Observatory's Island on the Lake Fatehsagar in India. Despite its limited size, the telescope is expected to
be competitive with respect to worldwide large and costly projects thanks to its versatility regarding science goals and
due to its demanding optomechanical and thermal specification. This paper describes the latest, on-going and
forthcoming activities, including factory assembly, integration and testing, followed by on-site installation and
commissioning activities. Emphasis is put on the highly demanding thermal control of the telescope, showing
development and results for the specific techniques employed on this purpose. Other key features also depicted are the
unusual tracking and alignment control solutions on such a specific science target like the Sun.
The Multi-Application Solar Telescope (MAST) is a 50 cm diameter class telescope to be installed on the Udaipur Solar
Observatory's Island on the Lake Fatehsagar in Udaipur, India. It is dedicated to solar observation. The telescope is
designed, manufactured, assembled and installed on-site by the belgian company AMOS SA for the Udaipur Solar
Observatory (USO), an academic division of the Physical Research Laboratory (PRL) in India. Despite its limited size,
the telescope is expected to be competitive with respect to worldwide large and costly projects thanks to its versatility
regarding science goals and also thanks to its demanding optomechanical and thermal specification. This paper describes
the optomechanical and thermal design of this telescope and presents solutions adopted by AMOS to meet the specific
requirements. The optical configuration of the telescope is based on an afocal off-axis gregorian combination integrated
on an Alt.-Az. mechanical mount, with a suite of flat folding mirrors to provide the required stationary collimated beam.
The entire funding has recently been obtained in Belgium for the construction of a 4m Liquid Mirror Telescope. Its prime focus will be equipped with a semi-conventional glass corrector allowing to correct for the TDI effect and a thinned, high quantum efficiency, 4K × 4K pixel equivalent CCD camera. It will be capable of subarcsecond imaging in the i'(760 nm) and possibly r', g' band(s) over a field of ~ 30' in diameter. This facility will be entirely dedicated to a deep photometric and astrometric variability survey over a period of ~ 5 years. In this paper, the working principle of liquid mirror telescopes is first recalled, along with the advantages and disadvantages of the latter over classical telescopes. Several science cases are described. For a good access to one of the galactic poles, the best image quality sites for the ILMT are located either in Northern Chile (latitude near -29°30') or in North-East India (Nainital Hills, latitude near +29°30'). At those geographic latitudes, a deep (i' = 22.5 mag.) survey will approximately cover 90 square degrees at high galactic latitude, which is very useful for gravitational lensing studies as well as for the identification of various classes of interesting galactic and extragalactic objects (cf. microlensed stars, supernovae, clusters, etc.). A description of the telescope, its instrumentation and the handling of the data is also presented.