_                    
                                                         |_|                   
      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                   
                                                          /                    
      ***  N    E    W    S  ***                        <)                     
 

IOC, SWG, LTS MEETINGS AT ISAS

This past week a number of acronym-inous (fortunately NOT acrimonious!) meetings were held at ISAS. The In-Orbit Checkout (IOC) was the topic of discussions on Monday and Tuesday, with plans for the post-launch check-out of the satellite being firmed up, and satellite `common-bus' system tests and observing system tests being integrated where possible. With the delay of the VSOP satellite launch until the January/February 1997 window, an extension to the series of on-going ground radio telescope and tracking station interface and performance tests has been proposed. The IOC Team membership was also discussed, with the Team to be lead by T. Kii, H. Kobayashi and E. Fomalont. A Survey Working Group (SWG) meeting was held on Wednesday, with one of the main items of discussion being progress with pre-launch observations in order to finalize the Survey Program lists, and attempt to prioritize the Survey Program observations. A summary of this meeting will be sent to all SWG members next week.

Finally, a smaller meeting on VSOP observation scheduling was held on Thursday morning. Both long-term scheduling (LTS; e.g. in four month blocks) and short-term scheduling (on an experiment by experiment basis) plans were reviewed, and a scheduling workshop at ISAS slated for the week of October 7th.

8 m ANTENNA SURFACE TESTS

Final sub-reflector deployment tests were carried out recently at Mitsubishi, with everything proceeding smoothly. The illumination-weighted surface accuracy, measured at 1000 points on the surface, has reached 0.51mm rms, however uncertainties in thermal effects in orbit, in transforming the ground- based measurements to the in-orbit surface, repeatability after orbit, and antenna `pillowing' effects, result in some uncertainty in the final surface accuracy (and its time dependence), which may be closer to 0.7mm rms. Nevertheless, it is hoped that rms variations will be at the wavelength/20 level or less at 22 GHz when the antenna is in orbit.

NATURE and NURTURE

Recent issues of the journal Nature have contained articles of interest to VSOPers. The June 6 issue had a review of future space missions, with most of one page devoted to a description of VSOP and the international co-operation required for the success of the mission. The following week contained an item of correspondence relating to the planned launch of a number of low-earth- orbit telecommunications satellites, which threaten to interfere with observations in the 1610.6--1613.8 MHz band that radio-astronomers have carefully nurtured and protected over the years. The current design of Motorola's Iridium satellites, reportedly breaches the International Telecommunication Union requirement that its `secondary' use of this band does not interfere with the `primary' radio-astronomical allocation to this band. Such piracy of the spectrum is clearly a matter of concern for all astronomers.

 
 
       Editors: Phil Edwards and Hirax Hirabayashi