Development report on the ISEE mission

The status of the International Sun-Earth Explorer (ISEE) project, a cooperative effort by NASA and ESA, consisting of a pair of spacecraft, A and B, with carefully matched payloads to be launched in tandem into the same highly eccentric orbit, is reviewed. The third spacecraft, ISEE-C, will sit permanently in the solar wind. Topics such as neutral sheet crossing time predictions, data processing, and status of the project are dealt with.