Commission 44: Space & high energy astrophysics

The space missions have been expanded to almost every field of astronomy and relevant to every kind of astronomical objects or phenomena. Dozens of missions are now in orbits and another dozen of missions are under development, awaiting launches in coming years. These missions have explored and will solve the problems of the natures of neutron stars, black holes, super massive black holes haunting the Galactic center and AGN cores, far distant galaxies reaching to almost the edge of the Universe or the very instant of galaxy formation, as well as the origin of stars and planets. The golden age of space observations will continue and the advanced missions will provide great strides of progress, in a variety of fields of astronomy. A clear characteristics of these activities is that many of the missions are carried out by large consortia, with multi-discipline participants. Sometimes, collaborations are organized among multiple missions and with ground base observatories.The collaborations yield more valuable and comprehensive data sets and results. Many missions are international in hardware developments and data analysis. As the scale of missions becomes larger, international collaboration is indispensable to afford the high cost and work force needed. These developments should increase the importance of the activity of Division XI, but, at the same time, raise the complexity and difficulty of the activities. This is the issue which is mentioned in the chapter 1. The solution may not be easily found, but the problem should be discussed elsewhere. In any case, the future of space astronomy is very promising and prosperous. Many big missions are on the horizon and they will certainly contribute to promote astronomy in various aspects, but it should be stressed that small missions are also very important to cultivate new fields. Beppo-SAX, HETE-2, and Swings are good examples.