An infrared zoom for space applications

In this pager we present the basic concept of an instrument with variable i nput optics, which takes into account the severe constraints imposed by spa ce applications. Up to now such kind of device has never been proposed for any of the major space infrared instruments, in the infrared spectral regio n, in fact, the use of lenses can severely affect the efficiency of the sys tem and variable optics, using only mirrors, should be the baseline option. In order to show the possible applications of this optical device we descr ibe in some detail the implementation of two different designs of optical z oom on two infrared instruments having different conceptions and objectives , namely a Fourier non-imaging spectrometer and a grating imaging spectrome ter. The use of this instrument in many space experiments could have severa l interesting applications. (C) 2000 Elsevier Science Ltd. All rights reser ved.