_                   
                                                         |_|                  
      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  ***                        <)                    

ANNOUNCEMENT OF OPPORTUNITY

A total of 28 proposals were received in response to the fourth Announcement of Opportunity. This is a similar number to that received for the previous AO, however, given the tighter slewing constraints HALCA is now operating under, the response to AO4 is larger than many people anticipated. With a number of observations from highly ranked proposals from previous AOs already scheduled for early 2001, VSOP observing remains significantly over-subscribed. AO4 proposals have been sent to the Science Review Committee, and PIs (or their designated contact person) will be contacted in late November with the results of the SRC review. With AO deadlines now following the ground-based trimester system, the anticipated deadline for AO5 proposals is February 1st, 2001.

NASA SENIOR REVIEW

During a visit to ISAS last month, Guenther Riegler, Director of the Research Program Management Division of NASA's Office of Space Science, met with VSOP Team Members and confirmed that, as a result of NASA's Senior Review (see VSOP news 116), NASA funding of VSOP mission elements (tracking stations, correlator support etc) would continue until February 2002. Good news!

HALCA STATUS

HALCA has two star trackers to check and stabilize its pointing. Ideally, the star trackers (CCD cameras) are operated simultaneously so that the satellite can be pointed precisely and its residual drift rate determined. As mentioned in VSOP news 118, the orientation of HALCA's orbit over the past few months has been unfavorable for simultaneous use of the star trackers. Naturally, the effects of any small mis-alignment between the star trackers and the main antenna are compounded during such periods. As a result, several VSOP observations were cancelled, or were affected by HALCA's pointing drifting during the observation. Fortunately, HALCA's orbit has now precessed sufficiently that good simultaneous star tracker coverage is now often available. In addition, a correction has been made for the the slight star-tracker/main-antenna mis-alignment, resulting in a noticeable improvement in HALCA's pointing stability.

FEEDBACK DOWN UNDER

Within Australia, VLBI observing is conducted with the Long Baseline Array (LBA), operated by the Australia Telescope National Facility (ATNF), in collaboration with the University of Tasmania. VSOP observations of equatorial sources often use at least one the LBA telescopes, and observations of southern sources generally use all of them. The inaugural LBA Users meeting is being held at ATNF on Wednesday 25th October to get feedback on LBA operations and suggestions for changes and improvements. Input from VSOP users of LBA telescopes is welcomed and can be submitted by e-mail to Tasso Tziumis.

                Editors: Phil Edwards and Hirax Hirabayashi