1064 



U.S. -EUROPEAN COOPERATION IN SPACE SCIENCE 77 



One of these NASA/ESA space science planning meetings occurred 

 in June 1983, and the issues addressed exemplify the problems and po- 

 tential of a coordinated approach to future space science undertak- 

 ings. -'' Three areas of cooperation were discussed: 



• infrared astronomy 



• solar terrestrial research 



• planetary exploration 



In the first of these areas, in essence the United States and ESA 

 "agreed to disagree." The issue under discussion was the next step 

 beyond the highly successful U.S. -Dutch-British Infrared Astronomical 

 Satellite (IRAS) launched in early 1983. Both the United States and ESA 

 have developed future mission concepts, and the two approaches are 

 not compatible. The meeting noted both "NASA's strong interest in col- 

 laborating to develop a single major international infrared space 

 telescope facility" (presumably based on the U.S. mission concept) and 

 "the firm commitment of ESA" to its mission. Recognizing that "the dif- 

 ferences in orbit and launch vehicle restrict any major hardware col- 

 laboration," NASA and ESA agreed to coordinate the planning for the 

 separate missions to maximize their complementarity and overall scien- 

 tific return, but also for the time being abandoned any hope of a joint 

 mission. 



By contrast, an examination of the large number of missions under 

 study in the United States, Europe, and Japan in the area of solar ter- 

 restrial physics identified "considerable merit in considering a joint . . . 

 mission"; NASA and ESA established a working group, which will also 

 include Japan, to "look for joint missions which can satisfy the main 

 scientific requirements in a cost-effective way." Similarly, NASA and 

 ESA agreed in the planetary exploration area "to identify mutually 

 beneficial opportunities for cooperative missions." In particular, the 

 two agencies are to study a joint Saturn-Titan probe mission for a 1992 

 launch. Planetary exploration is one of the areas of international scien- 

 tific cooperation agreed on at the recent series of summit meetings and is 

 also the focus of attention of a National Academy of Sciences/Euro- 

 pean Science Foundation working group. A cooperative Saturn-Titan 

 mission, if feasible, would thus be politically as well as technically 

 significant. 



Another example of the benefits of a coordinated approach to mis- 

 sion planning in a particular area of science is found in U.S. -German in- 

 teraction in x-ray astronomy. A large community of investigators has 

 developed to use the data produced by NASA's High Energy 



