The first thing to say is that IUE has been a great success and we should all congratulate the agencies in the U.S.A., Europe and the U.K. and the many scientists and engineers involved in the project on making it possible. In surveying what has been achieved so far, it is important to remember that we may well have IUE with us for a further 3 or even 5 years, meaning that it may be operating right up to the time of launch of Space Telescope. Undoubtedly, observations with IUE will pioneer many fields which will be explored in much more depth by the Space Telescope - there is no reason why IUE should not scoop some of the topics originally thought to be only the province of the Space Telescope.
It was always recognized that the study of extragalactic objects would be difficult with IUE. As Michael Penston expresses it, most astronomers don’t try to do extragalactic astronomy with an 18-inch telescope. Nonetheless, many observers have used their observing time to make long exposures on faint objects and there is no question about the significance of the science which has been accomplished. My own experience has been entirely with quasars and radio galaxies and, now that many of the obvious bright objects have been observed, we have settled into a pattern of only attempting one object per 8 hour shift, switching between the long and short wavelength spectrographs in mid-shift. We then repeat the observations in the following shift. Our experience is that this procedure is valuable in distinguishing whether faint features are real or not. Because of the long projected life of IUE, we do not regard this as an extravagant use of time and it is to be hoped that many more observers will adopt this point of view.