****************** ASTRO-F Newsletter Vol.1 10/2003 ***************** This newsletter E-mail will be circulated about once every month to report up-to-date status of the ASTRO-F project. This newsletter will be sent to all members on the iris_observer list, those are interested in observing with ASTRO-F. ################ The Birth of a new Space Institution ################ From the 1st October, the 3 establishments of the Institute of Space and Astronautical Science (ISAS), the National Space Development Agency of Japan (NASDA) and the Japanese National Aerospace Laboratory (NAL) are integrated to form a single independent administrative corporation known as the Japan Aerospace Exploration Agency (JAXA, uchuu kouku gijutsu kenkyuu kaihatsu kikou). The Former "The Institute of Space and Astronautical Science" will become known as "The Japan Aerospace Exploration Agency, Institute of Space and Astronautical Science", although it will still be acceptable to refer to the institute as "ISAS" (uchuu ken in Japanese). The hope is to further develop this new organization. We realise that just after the merger that there may be various problems for people and we ask for your cooperation during this confusing period. ################### Recent Developments on ASTRO-F ################### Since this is the first installment of the newsletter, we will take some time to go over the main recent developments within the project. * The ASTRO-F flight Model was manufactured the year before last and was assembled between the Spring and the beginning of Summer last year. The first assembly test was carried out. Since this was the first test, many problems were found. These problems were fixed and further environment tests of each component were carried out. The final integration test started in April this year. Unfortunately, due to the problems with the mirror, we have been unable to test the scientific instruments but tests of the satellite flight model are continuing. When these tests are completed, we will be able to launch with confidence. * In the case of ASTRO-F, telemetry from the satellite immediately after launch will be received by the former NASDA ground station. During the observation phase there is a plan to receive data via an additional ESA ground station. Checks are needed to ensure that the telemetry from the satellite can be correctly received by both the (formally) NASDA and ESA ground stations. This test was carried out for the NASDA ground station in January of this year. The tests ran smoothly without any problems. For the ESA ground station, the tests were carried out at the European Space Operations Centre (ESOC) in Germany from the end of June and early July. Equipment (from Japan) were brought to the ESOC facility and although at first there seemed to be various problems, eventually the test progressed without incident. It was confirmed that there were no problems with the reception of the telemetry. * This year in March, in order to check whether the satellite could be correctly installed in the M-V rocket, the satellite was installed in the 3rd stage rocket and the nose faring. Although there were a few problematical points, basically it was confirmed that the installation was without incident and the combination of the satellite with the 3rd stage of the rocket looks very reliable. (http://www.ir.isas.jaxa.jp/ASTRO-F/Outreach/new/new_bn.html#0303) * The 4th Mission Program Meeting was held from the 9-11 of June. Including collaborative researchers from foreign countries there were 80 participants. This active debate included a report on the present status of ASTRO-F and also the observing plan. Your cooperation was greatly appreciated. * In March & April and again in August, the two focal-plane instruments, the Infrared Camera (IRC) and Far Infrared Surveyor (FIS) were integrated together into the cryostat and their performance evaluated . In the August test, the flight model cryostat was used. The FIS noise level was very high which alarmed many of you but it is gradually being improved. The results of these tests have been taken into consideration and are being used to revise the ASTRO-F Observing Manual. We ask for your patience for a while until the new version is released. ################### Problems with the ASTRO-F Mirror ################# We will briefly explain the cause of the mirror problem behind the launch delay of the ASTRO-F mission. The primary mirror is made from Silicon Carbide. In order to keep the heat expansion coefficient constant Super Invar pads (of low heat expansion) are adhered to the mirror. It is through these pads that the mirror is connected to the outside structure. After one of the integration tests last year, a vibration test at cryogenic temperature was carried out. As the telescope was removed from the cryostat. the adhesive peeled off and the mirror became detached. It was suspected that the blame lay with the adhesion process. The strength of the adhesion was improved and the mirror was re-set. This year in April, the cryogenic vibration test was re-conducted. However, this time the mirror's Silicon Carbide surface layer was damaged and once again the mirror became detached. A Think Tank comprised of Engineering researchers at its centre has been formed to discuss this issue. The following explanation has arisen. When the Super Invar is cooled below 200K it suffers a phase transition. There is a volume expansion and the heat expansion rate increases. However this effect went unnoticed. Due to this effect the adhesive area suffers great stress at very low temperatures. Moreover, during the vibration test, additional stress is supplemented by the vibration which breaks the adhesive layer. This is the current thinking on the cause of the problem. At the present, investigations are ongoing to confirm this theory and to find a suitable solution to the problem. Our present prospect on the reparation of the telescope is around February next year. ################## Next Months schedule for ASTRO-F ################## Due to the 1.5 year delay in the launch, the present integration test will be stopped in the first week of November. The test will recommence in December of next year. The final decision on the Mission Programs will also be postponed until around the Autumn of next year. The detailed schedule is yet to be decided but the time gained from the delay in the launch will be used to refine the observing program. ********************************************************************** **** ASTRO-F Newsletter Vol.1 (Oct. 2003) **** This issue is brought to you by Hiroshi Murakami **** English translation by Chris Pearson **** **** ASTRO-F Web: http://www.ir.isas.jaxa.jp/ASTRO-F/ **** **** ASTRO-F Newsletter is open for any researchers who are interested **** in observations with ASTRO-F. Subscription/unsubscription/change **** of e-mail address should be directed to iris_help. **** **** Queries this Newsletter and matters related to ASTRO-F, or general **** opinions are also sent to iris_help. ********************************************************************** === EOF