RadioAstron Monthly Notices

June 2003

Tasks and developments completed in the ASC

1. Monitoring of the development of the on-board 92-cm receiver (R-SRT-92 cm) ongoing at the KB GORIZONT in Nizhnii Novgorod:

a) Test-set device for the flight model has been manufactured;

2. Monitoring of the development of the on-board 1.35-cm receiver (R-SRT-1.35 cm) ongoing at the OKB IRE in Fryazino:

a) The programs and the methods of the receiver tests were composed, namely:

· Specifications on the reliability test;

· Specifications on the control checks;

· Plan of the constructive rework;

· Plan of the integrated tests;

b) Calculations of reliability and radio-endurance have been performed;

3. Engineering models of all scientific devices were delivered to LA as well as all tests sets and necessary documentation.

4. Adjusting and testing of Formatter blocks (input quadrature convertor – heterodyne frequency selector) were going in June. User manual for the ESGE of Formatter was issued.

5. Memo “On the Optimization of the RadioAstron Mission by Using Advanced Observing Methods at Ground Radio Telescopes and Tracking Stations, and the Advantages of Using On-board H-maser Standard and On-board Accelerometer” has been prepared and distributed for discussion.

6. “RadioAstron Mission Operations Handbook” was placed at the ASC Web-Site (in Russian).

7. SRT antenna feeds (22, 5 and 1,65 GHz) were tested at temperature range (- 150…+ 60) C; the results are positive.

8. 18-cm feed /receiver system was installed at Kalyazin radio telescope, and test measurements were conducted.

9. Measurements of the phase-locked loop frequency control in OHCFS-SRT were completed, and corresponding report has been written.

Tasks and developments completed in Lavochkin Association

1. All engineering devices delivered from the ASC passed reception check.

2. Thermo-Vacuum-Test (TVT) of Device Container (DC), equipped with the thermal models of scientific payload and assembled with the Thermo-Vacuum Model (TVM) of the Spacecraft Bus, was successfully accomplished.

3. Measurements of the full SRT surface accuracy were finished.

4. Assembling of all engineering devices was continuing.

Appendix - the list of used acronyms

ASC Astro Space Center of Lebedev Physical Instutute

Cold Plate cooled LNAs and antenna feed

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

EGSE Electronic Ground Support Equipment (Electronic Complex – all SRT electronics)

EM Engineering Model

FC Focal Container – hermetic package with the scientific payload; it contains receivers,

microwave synthesizer, control unit and is placed in focal site of dish

FM Focal Module = Focal Container+Cold Plate

LA Lavochkin Association

OHCFS-SRT Space Radio Telescope On-board Heterodyne and Clock Frequency Synthesizer set

OHFS-SRT Space Radio Telescope On-board Hydrogen Frequency Standard

ORFS-SRT Space Radio Telescope On-board Rubidium Frequency Standard Service Module,

Spacecraft bus – spacecraft itself (without payload)

SRT Space Radio Telescope (all scientific payload including 10-m dish)

TMS Spacecraft Telemetry System (technical)

TVT Thermo-Vacuum Tests

VIRK Scientific high rate (up to 2x72 Mbit/s) radio complex, including transponder

ZBIT Zero Baseline Interferometer Tests (ZBIT)