_                    
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      V   V   SSSS   OOO   PPPP                 \__      |_|      __/          
      V   V  S      O   O  P   P                   --____/ \____--             
      V   V   SSS   O   O  PPPP                    _ _ _ --- _ _ _             
       V V       S  O   O  P                      |_|_|_|  @|_|_|_|            
        V    SSSS    OOO   P                             o-o                   
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      ***  N    E    W    S  ***                        <)                     
 

INTRODUCTION

This is the first of a planned series of informal reports on VSOP (VLBI Space Observatory Programme) progress. The anticipated frequency of these reports is about one per fortnight. The aim will be to keep the length of the report to less than 60 lines (about one page of print-out). ISAS (the Institute of Space and Astronautical Science, Kanagawa, Japan) had its annual Open Day on Saturday 30th July. A record crowd of 14,000 visited during the day, and wandered among the various exhibits. The VSOP team set up a number of displays next to the clean room where the Muses-B integration tests are currently taking place. The record attendance was thought to be due to (a) the recent space shuttle flight by Japanese surgeon Chiaki Mukai, (b) interest in the Comet Shoemaker-Levy 9 collision with Jupiter, and (c) the good weather. Tokyo has been experiencing an unusually hot summer this year. The temperature on August 3rd reached 39.1 C, the hottest day on record for Tokyo. Temperatures should have cooled down somewhat by the VISC meeting though! The dates for the meeting are tentatively Tuesday October 25th to Thursday 27th. These dates are the best for seeing the Muses-B spacecraft in all its glory at ISAS, and suit the majority of the VISC members Hirax has been able to talk with so far.

MUSES-B INTEGRATION TESTS

The Muses-B Integration tests started at ISAS on June 13th. The tests have proceeded relatively smoothly, and are currently only about a week behind schedule. A number of bugs and problems have been encountered, as expected when the various components have been brought together for the first time. One example: testing of the heater control unit revealed that it was not functioning as expected. This was finally traced to the inputs to the IC that compares the measured temperature with the preset level to determine whether the heater should be switched on. It turned out the Least Significant Bits and Most Significant Bits on the inputs had been interchanged! A second example: the Image Rejection Mixer was found to not be as linear as required. Suppression to 20 dB is required, and was being achieved, but at the expense of noise being added into the data band. The fix to this problem is still under consideration. The first half of the integration testing ends on September 2nd, and the second half kicks off on September 28th. It is hoped Mitsubishi will have the antenna ready to join the integration testing by the end of September.

EXPRESS DELAYED

Of some concern to the VSOP team has been the delay in the launch of the EXPRESS (EXPeriment REentry Space System) mission. Launch of this joint Japanese-German mission was scheduled for this month, however delays in bringing equipment from Germany have seen the launch delayed until early next year. The EXPRESS mission will be the last launch using the M3S-II rocket. After it has been launched work will start on upgrading the launch facilities at Uchinoura for the first MV rocket, which will launch Muses-B. Any further delays in the EXPRESS launch could possibly mean a delay on the launch of Muses-B.

 
 
       Editors: Phil Edwards and Hirax Hirabayashi