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

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

2m

520kg

SSC (Solid-state Slit Camera) 32 CCD (Hamaphotonics) 200 cm2. 0.5-12keV 。 -60℃ with LHPRS Energy resolution: 150 eV @5.9keV

GSC (Gas Slit Camera) 12 proportional counters Total area:5350cm2

Energy:2-30keV 10μ ｍ dia. Carbon wire

for anode

ISS motion

International Space Station(ISS)

Japan Experiment Module “kibo”

MAXI

ISS orbit(November 25,2010)•Inclination 51.65 deg•Perigee Height 346 km•Apogee Height 357 km•Revolution per Day 15.73

Data Communication

STS12707/16 Launch07/21 attached

operation by Koichi Wakata and ISS Crew

MAXI activation08/03 MAXI power on08/17 GSC and SSC operation start 08/18 GSC first Image

MAXI Ethernet 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.

2009/07 2009/08 2009/09 2009/10 2009/11 2009/12 2010/01 2010/02 2010/03 2010/04 2010/05 2010/06 2010/07 2010/08 2010/09 2010/10 2010/11

MAXICheckout

phaseDaily data distribution was begun from 2010/12/15.

Ethernet communication trouble were some times occurred.

New Ethernet adaptor for MAXI was attached by ISS crew. Then, MAXI Ethernet trouble was repaired. Now, MAXI observation data are almost completely delivered .

MAXI output the data to 2 logical data channels .•IEEE-B1553 (LOW Rate Data Line 25kbps)•Ethernet (Medium Rate Data Line ~600kbps)

ISS Pressured space

HUB

NASA line router

JAXA line router

B1553controller

NASA lineAntenna system

/Storage

JAXA lineAntenna system

/Storage

JEMCommunication

processor

LOW Rate Data

Medium Rate Data

(backup line)

JAXA

NASAGND

system

~70% real time contact/24h

1hr real time contact/24h

New Ethernet adaptor for MAXI

Operation

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.

ISS Operation plan viewerAll of ISS activity (including commanding to MAXI system) has been planned before two weeks.

MAXI Data acquisition rateNew Ethernet adaptor for MAXIIt is consist of PC104 computer unit.

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.

11/26 Press release GSC all sky image

2009/12/15 Daily data distribution start

Crab LC

2010/11/03 spectrum of bright sources

Crab

Mission life > 2year

2 month integrated Image

One orbit Image

10cm

RIKEN

Novae alert