MAXI and ISS

1. In July 2009, MAXI and ”Kibo” Exposed Facility were delivered to International Space Station(ISS) by Space Shuttle Endeavour and were completed by the operation of Koichi Wakata and ISS Crew. MAXI was powered on in August/03/2009, and MAXI observation has been started from August/17/2009. We report the recent one year operation status of the MAXI and ISS. The operation of MAXI did not so go well easily. It suffered from some troubles of communications. ”Kibo” Operation team and MAXI Operation team have improved some onboard telecommunication system and the ground equipments to store MAXI data more completely. Now, MAXI observation data are almost completely delivered to our analysis system. MAXI and ISS MAXI • GSC(Gas Slit Camera) • 12 proportional counters • Total area:5350cm2 • Energy:2-30keV • 10μｍ dia. Carbon wire for anode Japan Experiment Module “kibo” 520kg ISS motion Operation Status of MAXI and ISSM.Kohama,H.Tomida,S.Ueno,Y.Adachi,H.Itamoto,M.Ishikawa,K.Kawasaki(JAXA),T.Mihara,M.Sugizaki,M.Serino,M.Matsuoka(RIKEN),H. Negoro(Nihon univ.)and MAXI Team International Space Station(ISS) • SSC (Solid-state Slit Camera) • 32 CCD • (Hamaphotonics) • 200 cm2. 0.5-12keV。 • -60℃with LHPRS • Energy resolution: 150 eV @5.9keV • ISS orbit • (November 25,2010) • Inclination 51.65 deg • Perigee Height 346 km • Apogee Height 357 km • Revolution per Day 15.73 2m Mission life > 2year Operation Data Communication • MAXI output the data to 2 logical data channels . • IEEE-B1553 (LOW Rate Data Line 25kbps) • Ethernet (Medium Rate Data Line ~600kbps) ISS Operation plan viewer All of ISS activity (including commanding to MAXI system) has been planned before two weeks. ~70% real time contact/24h ISS Pressured space NASA GND system JAXA RIKEN B1553 controller JEM Communication processor NASA line Antenna system /Storage So as not to give the obstacle to the ISS crew activity, the commanding to the ISS equipment from ground system is planned very severely. In MAXI, the file transfer for the observation plan and the commanding for updating this file every day are put in the ISS operation plan, and it is executed every day. LOW Rate Data NASA line router HUB New Ethernet adaptor for MAXI Medium Rate Data JAXA line Antenna system /Storage JAXA line router 1hr real time contact/24h Novae alert (backup line) 2010/08 2010/06 2010/09 2010/04 2010/05 2010/07 2010/10 2010/11 2010/02 2010/03 2009/07 2009/08 2010/01 2009/09 2009/10 2009/11 2009/12 MAXI Checkout phase Daily data distribution was begun from 2010/12/15. Ethernet communication trouble were some times occurred. STS127 07/16Launch 07/21 attached operation by Koichi Wakata and ISS Crew MAXIEthernet trouble was occurred. Whenever the trouble of the Ethernet communication , we had to reboot the MAXI system. We experienced rebooting 17 times by March, 2010. New Ethernet adaptor for MAXI was attached by ISS crew. Then, MAXI Ethernet trouble was repaired. Now, MAXI observation data are almost completely delivered . New Ethernet adaptor for MAXI It is consist of PC104 computer unit. MAXI Data acquisition rate 10cm 2009/12/15 Daily data distribution start Crab LC 2010/11/03 spectrum of bright sources Crab The Low Rate Data Line keeps stabilizing very much since the beginning of mission. Resent data losses are due to the maintenance of the ground equipment . These can be collected later. On the other hand, after the installation of new Ethernet adaptor , the Medium Rate Data Line is very stabilized though it was very unstable at first. MAXIactivation 08/03 MAXI power on 08/17 GSC and SSC operation start 08/18 GSC first Image 11/26 Press release GSC all sky image 2 month integrated Image One orbit Image