_                   
                                                         |_|                  
      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  ***                        <)                    

HALCA STATUS

Observing with HALCA has temporarily been halted: on August 30th, HALCA stopped sending its on-board status in its telemetry down-link signal. Operating the spacecraft for observing under such situation is dangerous and so the VSOG decided to cancel the current observing schedule and return the observing time to the ground telescope arrays and networks. The VSOG has since been operating HALCA with the greatest care, and has been trying to understand the phenomenon and determine how best to recover. HALCA's attitude, normally checked in house-keeping data in the down-link telemetry, has been monitored at the tracking stations (particularly Usuda) using the Ku-band down-link beam-pattern and power levels. It is thought a stoppage of the frame header clock for the telemetry signal generator is the problem, and that resetting the on-board Data Handling Unit is likely to restore HALCA to its fully operational state. More details will follow after further checks and studies.

WHERE IS HALCA NOW?

A recent addition to the VSOP web-site is a page showing a simulated view of the Earth as seen from HALCA. The page updates itself every five minutes, and over a few hours the Earth can be seen to recede (or approach) quite spectacularly. The satellite's "view" is generated by the FAKESAT package, and the display script (like much of FAKESAT) was developed by Dave Murphy (JPL).

INTEGRAL MEETING

The third INTEGRAL (International Gamma-Ray Astrophysics Laboratory) meeting, titled The Extreme Universe, is being held next week in Sicily. VSOP Project Scientist, Prof. "Hirax" Hirabayashi, is attending the meeting and will present an invited talk "Recent Results from VSOP Observations" on Friday 18th September. Further details of the meeting are available at http://www.ias.rm.cnr.it/ias-home/imager/tao98.htm .

OLIVE

The Optically Linked VLBI Experiment (see VSOP news issues 48 and 50) has recently obtained its first successful cross-correlations with data from the Usuda 64m and Nobeyama 45m telescopes, which were transferred to a one-baseline correlator at ISAS's Sagamihara campus and correlated in real-time. The observations, at 22 GHz, were made of W49N and 3C454.3.

 
                Editors: Phil Edwards and Hirax Hirabayashi