Independently of the disasters observed on Earth, more than 600 space weather events are observed per solar cycle (11 years). When they occur during the response phase of a disaster (the first two weeks) they may seriously affect: satellite orientation, communication systems and navigation systems. Alert systems allow identifying in near real-time (Δt≤ 15 minutes) corrupted or missing communications. For the sake of convenience the space weather events discussed here are mainly those generated by “geomagnetic storms” characterized by Kp or K indexes. Applications are made: (i) during the response phase of the 26th December 2004 earthquake and its subsequent tsunami, and (ii) for near real time observations.