With the various space missions now under development and on the drawing 

 boards, both in the United States and abroad, it is clear that much progress is to 

 be expected in exobiological science. It thus seemed important to study the 

 extent to which Earth-orbiting space missions, such as the Space Station, might 

 make useful contributions. A priori, it would appear attractive to utilize such 

 permanently orbiting facilities to observe a wide range of objects, from inter- 

 stellar clouds to solar system bodies; to collect cosmic materials for subsequent 

 analysis; and to conduct in situ experiments, taking advantage of the natural 

 environment of space. The subsequent sections of this publication are devoted to 

 a critical examination of these possibilities, as well as to a consideration of other 

 ways in which they could provide definitive insights for exobiological science. 



