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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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*** R E P O R T *** <)
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Hirax Hirabayashi & Phil Edwards November 1994
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This is a summary of recent progress made on the VSOP project. The satellite depiction above shows the main antenna, subreflector, solar panels, main body with star tracker, two reaction control system tanks and the Ku-band antenna.
ISAS OPEN DAY
A record crowd of 14,000 attended the annual ISAS Open Day on Saturday 30th July. The VSOP team set up a number of displays next to the clean room where the Muses-B integration tests were then taking place. A 1/10 scale model of the Muses-B satellite took pride of place in the Open Day display. It is now exhibited in the foyer of the Main Building at ISAS.
MUSES-B INTEGRATION TESTS
The Muses-B first integration tests (`ichikami') started at ISAS on June 13th. A number of bugs and problems were encountered, as expected when the various components had been brought together for the first time. These ranged from the relatively minor reversal of bits between units, to more serious problems with electrical interference between components.
Signals sent both via the satellite downlink system and through the ground radio telescope equipment were successfully correlated during the tests. Tests of the main antenna surface, a gold-plated molybdenum mesh, were made at the Mitsubishi factory. Boom deployment tests, with the booms supported by counterweights to simulate zero-gravity, were also conducted at Mitsubishi. The main antenna mesh was not transported to ISAS for testing. A successful partial deployment of the main antenna support booms was made on October 25th, and commands to initiate the sub-reflector deployment were tested the following day.
The `ichikami' tests were completed on schedule on Friday November 11th. The Attitude Control System - reaction wheels, gyros, magnetic torquers, star trackers etc - will remain at ISAS for further testing until February next year.
M-V ROCKET TESTS
Muses-B is planned to be the first launch with the ISAS developed M-V rocket. The three-stage, solid fuel, rocket allows a launch of payloads up to 1800kg in low Earth orbit, or 800kg into a Muses-B type orbit.
A successful 1st-stage test firing was carried out on the 21st of June at ISAS's testing facility at Noshiro, Akita prefecture, about 500 kilometers north of Tokyo.
The first test of the M-V rocket's kick motor was made on the 28th of September. The kick motor is used to boost the satellite into an orbit with the desired apogee. The Reaction Control System is then used to raise the perigee of the orbit. The test firing lasted approximately 80 seconds and was a resounding success.
A 95 second test firing of the 2nd stage of the M-V rocket was successfully made at Noshiro on October 27th. The 3rd stage is scheduled for testing in March 1995.
TRACKING STATIONS & TELEMETRY COMPATIBILITY TESTS
Usuda will be the site of a new 10m tracking station for VSOP. Work on the foundations began in November, with the antenna expected to be installed and operational by November 1995.
Compatibility tests for the K-band ground telemetry station electronics were carried out in September in the USA. Testing took place JPL, Scientific Atlanta and Green Bank. The Muses-B on-board simulator, assembled from engineering model modules, was sent from Japan with two VSOP team members for the tests.
Late next year the SURFSAT-1 spacecraft will be launched as a secondary payload on a NASA rocket. As the spacecraft will carry low power radio transmitters, it is envisaged that pre-launch tracking station tests for the VSOP mission will be carried out using SURFSAT.
CORRELATOR TESTING
Three station testing of the VSOP correlator hardware has ended, with no major hitches being experienced. Correlator software testing started on October 17th. The correlator is expected to be ready by February 1995. The VSOP correlator will use the VSOP format as its input, and so two VLBA-to-VSOP copiers and one S2-to-VSOP copier are being developed for data translation.
VSOG & VISC MEETINGS
A series of meetings was held at ISAS in the last week of October to review progress made both within Japan and on the extended international support network for the VSOP mission. The VSOP Science Operations Group (VSOG) met on the 24th and 25th and the VSOP International Science Council (VISC) convened on the 26th and 27th. Telemetry support and orbit determination concerns were discussed in meetings on the 27th and 31st. At the conclusion of the VISC meeting H. Hirabayashi and D. Jauncey were appointed new VISC co-chairs, replacing M. Morimoto and A. Zensus. A highlight of the week was the performance, in Japanese, by the JPL "Zou-san singers" at the VISC meeting banquet. This may have provided the inspiration for others to try their hand at karaoke later in the week. The next VISC meeting will be held in the week of 27th March 1995 at Pasadena.
WORLD WIDE WEB & NEWSLETTERS
The JPL Space VLBI Project has released its home page on the World Wide Web. A variety of information is now on line, describing the JPL Project, and the VSOP and RadioAstron space missions. An ISAS VSOP home page will be released in the near future. VSOP, RadioAstron and JPL Space VLBI project newsletters are being regularly produced to keep people informed of progress.
THE FIRST AO
The first VSOP Announcement of Opportunity is planned for release in May 1995. Details are still being finalised, however it is envisaged that an announcement of the release of the first AO, with details of how the full text of the AO can be obtained, will be distributed by e-mail. The full text will be available from anonymous ftp sites and also from the World Wide Web. People will shortly be able to register their e-mail address for notification of the AO release announcement. Electronic submission of proposals will be very strongly encouraged, in part to enable proposal details to be transferred to a database to facilitate the scheduling process. The deadline for proposals will be approximately six months after the AO release. Proposals will be peer reviewed by a committee to be appointed by the VISC.
FELLOWSHIPS TO JAPAN
ISAS and the National Astronomical Observatory are both able to host foreign researchers at the research fellow and visiting professor levels. These positions are typically for a one-year period.
The VSOP Project team is strongly supportive of fellowship applications by people wishing to work on the VSOP Project in Japan. Indeed, particularly leading up to, and following on from, the launch in 1996, support from abroad will be essential for the project's success. A list of fellowship schemes is being compiled for circulation in the near future.
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