ose to the Earth [Daly-88]. Figure 2 translates these fluxes into the actual dose a silicon device receives at a given location per second, from trapped electron and proton belts, being shielded by 2.1 millimeters of aluminum (CRRES experiment data). As for fig. 1, these data are recorded for a "quiet" situation, i.e. without enhancement due to Solar transient activiy. CRRES Dosimeter Combined Hilet and Lolet dome 1 (82.5) mils AL [7MAY92] binned from (CRRES orbits 4 to 575) 27 Jul 90 to 19 Mar 5.00E-2 Dipole Axis 1.00E-4 Limits of CRRES Bins Figure 2. In-orbit dose rate received behind a 2.1 mm Al shield [Kern-92]. THE ORBITS AND EXAMPLE OF MISSION DOSE PROFILES Constellations of satellites devoted to the global consumer market, have been the major innovations of the last decade. These telecommunication constellations had been preceded by military networks and by Global Positioning Networks such as GPS in the United States and Glonass in the former USSR. As the push of the telecommunication market requires more complex features of satellites, the altitude of the orbits gets more into the radiation belts and the total dose or ionizing radiation absorbed increases. Table 1 and fig. 3 depict some examples. It can be seen that the next III-5 generation of systems will roughly need to endure 10 times more radiation dose than the present Status perigee X apogee/inclin. External Dose Dose / 1 mm Alu. Manned LEO: Space Stations Space Station project 450 X 450 km 51° 150 krad/year 1 krad/year Little or Big Low Earth Orbit (<2000km): Constellations Iridium operational 780 x 780 km 1.7 Mrad/year 9 krad/year note: with overshielding = > 1 krad/year Celestri project (abandoned) 1400 X 1400 48° 17 M 1rad/year 63 krad/year Teledesic project 1400 X 1400 84.6° 18 M rad/year 51 krad/year Skybridge project 1457 X 1457 28 M rad/year 73 krad/year note: with overshielding = > 7 krad/year project 2000 x 2000 81 Mrad/year 670 krad/year note: with overshielding = 50 krad/year MEO (10000km)/GEO (36000km): GPS, Telecommunication Relays,et