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of the RadioAstron Teleconference 2
April 4, 2003
Willem Baan chaired the
teleconference.
The agenda of the teleconference and
the list of participants are attached as an Appendix A to the Minutes, and list
of used acronyms and conventional names is given as an Appendix B.
The main purpose of the
teleconference was to review the progress on the RadioAstron project during the
first quarter of 2003.
The following conclusions and action
items were developed as a result of the discussions:
1. Kardashev
informed the participants about the technical progress in the development
project. He specified the following achievements:
1.1.
Technical documentation for the thermo‑vacuum tests (TVT) of the
spacecraft and the SRT device module was written. Preparations are made for the
TVT.
1.2.
The Focal Container (hardware) and the cables are prepared at LA for assembly
into the Electronic Complex (engineering models), which will be delivered to LA
from ASC.
1.3.
Geometrical adjustment of the antenna petals is continued at LA using the
"adjusting points" technique.
1.4.
The SRT assembly of the special configuration for the Pushchino tests was
started at LA.
1.5.
The checkout of the Focal Container electronics (Electronic Module) is being
done at ASC before delivery to LA.
1.6.
Determination of the SNR at the correlator output for different parameters of
the Zero Base Interferometer has been done at ASC.
1.7.
Technical documentation, necessary for the input checkout and the assembly at
LA of the engineering models of the scientific payload for future Pushchino
tests, was written at ASC.
2. Kardashev
informed the participants about the time-line for the project development in
2003. He ensured the participants that
the funding necessary for project development in 2003 is anticipated to be
provided in full. He emphasized that the following tasks need to be completed
in 2003:
2.1.
Thermo-vacuum tests of the Spacecraft Bus and the SRT Device Module together
with the cooling system of the LNAs.
2.2.
Manufacturing of the transportation bus for SRT shipment to Pushchino. (LA,
July).
2.3.
SRT antenna reflector mounting and assembly for the Puschino tests. (LA, April
- July).
2.4.
Preparation, delivery and input checkout of the Electronic Complex (and documentation)
for SRT assembly together with antenna and mechanisms. (ASC/LA, May - June).
2.5.
Preparation and delivery of SRT Test Sets and the SRT tests after assembly at
LA. Transportation to Puschino. (ASC/LA, July - August).
2.6.
Preparation of Puschino Polygon (test facilities) and ground-based equipment.
(ASC, June - July).
2.7.
Assembly, mounting, checkout and tests of Engineering Model of the SRT in
Puschino. (ASC, August - October).
2.8.
Modernization of the SC bus equipment (TMS, radio channel, computer). (LA,March
- December).
The Chairman suggested that ASC
distribute monthly e-mail reports on the various activities in the RadioAstron
project in order to keep all RISC members and telecon participants informed on
the progress.
3. Kardashev
provided clarification concerning the Technical Task TZ document, which is
equivalent to the NASA designation of Project Plan. The document was
distributed before the teleconference in raw translation into English. The
document has been approved by the Director of ASC (Kardashev) and by the
Director General of LA (Kulikov), but it has not yet been approved by the
President of Russian Academy of Science and by Director General of Russian
Aviation-Space Agency. The reason for this is the uncertainty about two main
items, which are the on-board H-maser frequency standard and the configuration
of tracking stations. The Technical Task (TZ) document does not treat the
international collaboration in the Mission and these aspects of the mission
will have to be described in separate agreements between the participating
institutions.
4. A
complex discussion followed on the advisability of implementing an on-board
H-maser frequency standard. On the one hand, the H-maser has been included in
the on-board science payload according to item 6.1.8. of the TZ and only a
well-argued formal decision would be needed to eliminate it. On the other hand,
there are strong doubts whether the manufacture and delivery of an H-maser will
be possible in the given time limit and within the available funds (Gurvits).
There was also the opinion expressed by Kellermann that the on-board H-maser is
not a crucial element for the mission and may be treated as a supplementary
non-essential device.
In
response to this discussion, Kardashev informed the participants that a
Memorandum on the advantages of implementing an on-board H-maser and an
ultra-sensitive accelerometer is under development at the ASC. The most
important question is to understand the influence of an H-maser on the maximum
integration time and the sensitivity. The Memorandum will naturally include a
comparison of mission parameters that will be achieved with and without the
H-maser and the accelerometer. Kardashev invited foreign assistance in the
development of this Memorandum, especially from those having experience with
the VSOP mission. The Memorandum is planned before the next teleconference in
the middle of June.
5. Baan
raised the issue of tracking stations and particularly the status of
development of Pushchino tracking station. Kardashev responded that necessary
technical documentation for the instrumentation of Pushchino tracking station
were prepared at ASC, but that no implementation has been started yet, because
the ASC is waiting for the NASA response on a request to transfer some hardware
from other NASA tracking stations. Mark Allen commented on this that earlier
this year the Astrophysics Advisory Committee considered NASA participation in
RadioAstron, and that its report was submitted to the Space Science Advisory
Committee in March. A decision will be available in a few weeks. Kardashev
emphasized that the operation of the Mission with Puschino as only tracking
station would reduce the efficiency to about 30%. In order to have a higher
efficiency, the Mission needs two extra tracking stations: one in the western
hemisphere and one in the southern hemisphere (Green Bank and Tidbinbilla).
6. Popov
reported on the current RISC membership. The following list presents the
current status; the first line is the addressee whom the ASC sent the request,
and the nominated member is indicated in the every second line below:
David Southwood, ESA, France,
Kornelis
Van Klooster
Ron
Ekers, ATNF, Epping, Australia
David Jauncey
Phil Diamond, EVN, Jodrell Bank, UK
Phil
Diamond (Willem Baan), Leonid Gurvits
Hiroki Matsuo, ISAS, Sagamihara,
Japan
Hisashi
Hirabayashi
Anssi Malkki, FMI, Helsinki, Finland
Seppo
Urpo
Zhao Junliang, ShAO, Shanghai, China
Xiaoyo Hong
Alain Maurissen, Neuchatel
Observatory, Switzerland
Alain
Maurissen
Leonid Lytvyenko, IRA, Kharkov,
Ukraine
Leonid
Lytvyenko
Anton Zensus, MPIfR, Bonn, Germany
Anton
Zensus
Rajaram Nityananda, NCRA, TIFR,
Pune, India
S.Anathakrishnan
Bernard Burke, MIT, Cambridge, USA
Bernard
Burke
No request was sent to Canada
because ASC is waiting for a reaction from the Canadian Space Agency on the
letter sent from the Russian Aviation and Space Agency with a proposal to
participate in the RadioAstron project.
No response has been received from
the following addressees:
Fred K.Y. Lo, NRAO, Charlottesville,
USA
Marc S. Allen, NASA, Washington, USA
Gianni Tofani, IRA, Bologna, Italy
Daniel Altschuler, Chris Saulter,
Arecibo Observatory, NAIC, USA
Norbert Bartel, York University,
Toronto, Canada
7. Popov
informed the participants that comments on the Terms of Reference (version 3
from December 10 2002) are invited. The document will be present for approval
at the next RadioAstron meeting in Moscow in November 2003.
8. The
date for the next RadioAstron meeting was set for November 10-12, 2003.
9. The
next teleconference is planned for July 3, 2003.
10. Action
Items resulting from the discussions:
April03-1. Memorandum on the advisability of
implementation of the on-board H-maser and ultra-sensitive accelerometer to be
prepared by ASC before telecon in June 2003.
April03-2. Monthly reports on the main
achievements in project development will be distributed by ASC at the end of
every months starting from April 2003.
April03-3. Chairmen of the Working Groups are
urged to submit a Plan of Activities of the Working Groups for discussion at
the next teleconference.
Appendix A
Agenda for the Teleconference on
RadioAstron on April 4 2003.
1. Sound check and attendance.
2. Review and corrections of the
telecon agenda - Chairman
3. Technical progress and time-line
for 2003 - N.Kardashev
3.1. Technical Task document (TZ)
3.2. Spacecraft Bus
3.3. Science Payload
3.4. Tracking Stations
4. New RISC members - M.Popov.
5. Status of the development of the
Terms of Reference - M.Popov
6. To set the date of the next
RadioAstron meeting (Moscow, 3-5 November 2003).
7. Suggested date for the next
teleconference June 26 2003.
List of participants
1. Allen M. NASA, USA
2.
Altunin V.I., JPL NASA, USA
3.
Andreyanov V., ASC, Russia
4.
Baan W.A., ASTRON, The Netherlands
5.
Babakin N., ASC, Russia
6.
Babyshkin V.E., LA, Russia
7.
Bartel N., York University, Canada
8.
Belousov K., ASC, Russia
9.
Burke B., MIT, USA
10. Cannon W., CRESTech, Canada
11. D'Addario L., NRAO, USA
12. Fomalont E., NRAO, USA
13. Gurvits L., JIVE, The
Netherlands
14. Hayes J., NASA, USA
15. Van't Klooster K., ESA, The
Netherlands
16. Kanevsky B., ASC, Russia
17. Kardashev N.S., ASC, Russia
18. Kellermann K., NRAO, USA
19. Kovalev Yu., NRAO, USA
20. Lobanov A., MPIfR, Germany
21.
Langston G., NRAO, USA
22. Popov M.V., ASC, Russia
23. Preston R., JPL NASA, USA
24. Rausch D., NASA, USA
25. Romney J., NRAO, USA
26. Savinell C., NASA, USA
27. Slysh V.I., ASC, Russia
28. Urpo S., HUT, Finland
29. Vasilkov V.I., ASC, Russia
30. Zensus A., MPIfR, Germany
Appendix B
The list of used acronyms
ASC Astro
Space Center of Lebedev Physical Instutute
SRT Space
Radio Telescope (all scientific payload including 10-m dish)
TMS Spacecraft
Telemetry System (technical)
VIRK Scientific high rate (up to 2x72 Mbit/s) radio complex,
including transponder
EM
Engineering Model
Focal Container – hermetic package
with the scientific payload; it contains receivers, microwave synthesizer,
control unit and is placed in focal site of dish
Cold Plate – cooled LNAs and antenna
feed
FM Focal Module = Focal Container+Cold Plate
DC – hermetic device container (part
of payload); it contains Formatter, Rb oscillators, synthesizer, control unit
and is placed under dish
DM Device Module = DC + H-maser
Electronic Complex – all SRT
electronics
TVT - Termo-Vacuum Tests
LA - Lavochkin
Association
Service Module, Spacecraft bus –
spacecraft itself (without payload); sometimes in text Spacecraft =service
module + payload