The QUASAT Project

Abstract

Preston et al (1976) and Burke (1982, these proceedings) have long extolled the virtues of launching a radio telescope into space to increase VLBI baseline lengths and thus angular resolution, and to provide a much enhanced image formation capability. The scientific motivation for this has been covered in a number of memoranda referenced by Burke in these proceedings, and by Anderson et al (1982). Efforts to mobilise western astronomical support for space VLBI met with success in late 1982 at a meeting of US and European radio astronomers in Toulouse, France, at which a decision was taken to propose a joint mission to ESA and NASA. Shortly thereafter, a formal proposal was made to ESA (Anderson et al 1982) for a free flying satellite in an elliptical orbit out to 15000 km from the Earth, designed to observe in concert with the major ground-based VLBI networks and arrays. The mission, dubbed QUASAT, was received favourably in both ESA and NASA, with the result that formal Assessment Studies are scheduled to begin in both agencies in October 1983.

Space VLBI: from first ideas to operational missions

“…Not surprisingly, SVLBI observations with VSOP and RadioAstron were much less sensitive than contemporary Earth-based VLBI experiments. Larger apertures of space-borne elements of SVLBI systems have been considered in the 1980s-90s: QUASAT, 15 m, (Schilizzi et al, 1984); IVS, 25 m (Pilbratt, 1991); ARISE, 25-30 m (Ulvestad et al, 1997;Ulvestad, 1999); KRT-30, 30 m (Kardashev et al, 1980). In the two implemented SVLBI missions as well as in all mentioned concept studies, the main reflector of the telescope was "pushing" the launch capability to the limit.…”

“…Several of them reached a pre-design study stage in the 1970searly 1990s. Among them, the most prominent were the European-led concept QUASAT (Schilizzi et al, 1984), the Soviet project KRT-30 as a part of the RACSAS system (Kardashev et al (1980), Sagdeev (1984), Davies (1997, Ch. 9) and Hendrickx & Vis (2007, Ch.…”

A model of geometric delay in Space VLBI

“…This technique is called SVLBI. SVLBI projects have been proposed or planned by several agencies: Quasat by the European Space Agency and NASA in 1980s (Schilizzi 1984(Schilizzi , 1988, VSOP by Institute for Space and Astronautical Science in Japan (Hirabayashi 1988), which was launched successfully in February 12,1997 (Hirabayashi et al 1997a,b), and RADIOASTRON by the Space Research Institute of the USSR Academy of Science (Kardashev et al 1987), which was launched in July 18, 2011 (Alexandrov et al 2012). The Chinese Space VLBI project (hereafter C-SVLBI), which is proposed by Shanghai Astronomical Observatory and National Space Science Center of China recently, plans to launch two antennas into Earth orbit in the first step (Hong et al 2013;Shen et al 2013).…”