JAS-2: Launch and after- - - -


JAS-2 was successfully launched on August 17, 1996, by H-II rocket No.4, along with the earth observation platform satellite ADEOS, from Tanegashima Space Center of NASDA. Lift-off time was 1053 JST, or 0153 UTC, and after some 38 minutes, JAS-2 was separated. Separation was first reported by NASDA, and then a few minutes later report of signal reception of JAS-2 was transfered to the Space Center from Showa Base at Antarctica through INMARSAT link (1). Control station in JARL headquarters in Tokyo cheered hearing this report, and waiting one hour, clear signal "HI HI ......" came out from the speaker. Yes, sure it was from JAS-2, applause occurred. Immediately, Morse code recording started. Letter by letter, one clue filled paper with two digit telemetry data, and then data were analyzed. ....Bus voltage is okay, solar cell current enugh, storage battery temperature moderate, and soon, .... Telemetry data showed that health of JAS-2 seemed normal. After this pass, JAS-2 cannot be seen at Tokyo for about six hours. Evening, we got AOS at 2056 JST and during this pass a number of commands were transmitted and verified and also in next pass around 2241. During these passes JAS-2 had been in mode JA with beacon telemetry. Using thisbeacon signal, we observed Doppler shift of its frequency for checking orbit. First orbit prediction was done using flight plan of rocket, and Doppler shift curve showed fairly good fitting with calculated one. After several passes we had confidence of these observation result to use as orbit element. We could know these Keps were not so different from the two-lines first announced by NASA on August 21. August 18, during the evening pass began at 2146 digital transponder were turned on, and there came a familiar tone of 1200bps packet. For trial we wrote the first message, and then read out it. Okay, BBs must work well. In next pass we found some messages written in BBS. After checking out transponders, attitude control will start. It will take longer time to build up proper attitude and to get spinning. Occasional turning on and off of transponder shall be done without notice until satellite will get stationary condition. Full opening of JAS-2 will be announced when it becomes ready. (1) Telemetry data were acquired by NASDA station at Showa Base in the Antarctica, where the amateur station 8J1RL is also equipped and radio amateurs there tried to receive signal from JAS-2 and succeeded, probably firstly.
To learn more about H-II rocket and launching schedule, please visit the web at http://www.nasda.go.jp/.

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