T-170-M telescope, cameras and the FGS:

interfaces, requirements etc.

Alexander MOISHEEVLavochkin Association

moisheev@laspace.ru

ASI/Roscosmos Meeting Rome, December 20, 2005

The WSO/UV S/C

S/C main featuresS/C main features

• Platform (Service Module –SM) Navigator• Mass of S/C with propellant 2900 kg• SM mass 1300 kg• Mass of propellant of the SM 150 kg Propellant of the SM: Hydrazine • Mass of the P/L 1600 kg• Pointing accuracy with star sensors 4 (2) arc.min.

• Accuracy of pointing and stabilization 0.1 arc.sec with the FGS;

• Slewing rate up to 0.1 deg/s • Maximal exposure time 30 hours • Download rate of scientific data up to 1 Mbaud• H/K data transmission rate up to 32 Kbps• Electric power available for the P/L 750 W

For science instruments of the 300 W

Focal Plane Compartment • Voltage of electric power supply 27±1,35V

S/C main features (ctd.)S/C main features (ctd.)

Initial design requirements to T-170M

Optical system Ritchey – Chretien aplanat

Aperture diameter 1700 mm

Telescope f-number 10.0

FOV 0.50 (150mm in diameter)

Wavelengths range 100 – 350 nm (+visible)

Primary wavelength 200 nm

Optical quality Diffraction optics at the FOV center

Mass 1570 kg (1600 with adapter truss)

Size 5.67м ×2.30 m (transport)8.43 * 2.3 m (operational)

T-170M FP layout

HIRDES slits are placed 50mm off-axis

SFUV cameras: FOV- 6 arcmin circularSFVIS camera: FOV- 6x6 arcmin squaredFOV’s centers are located 30mm off-axis

LFUV cameras: FOV- 1.2 arcmin circularLFVIS camera: FOV- 1.2x1.2 arcmin

squaredFOV’s centers are located 35mm off-axis

FGS cameras FOV- 4x3 arcmin rectangularFOV’s centers are located 60mm off-axis

Optics Quality Control System is on axisFOV - non

Spectropolarimeter (excluded)FOV – 6 arcmin circularFOV’s center is located 60 mm off-axis

Optical Adjustment Control System is placed 60mm off-axis (proposed)

Exploded view of the instrumental compartment

Concept:

All cameras in one unit – Field Cameras Unit

For estimates of size, mass, electrical properties etc the TAUVEX camera (Israel) is considered as prototype of the UV-cameras

Field cameras

Field Cameras Unit (FCU)Field Cameras Unit (FCU)

LF-UV2 SF-UV1

FCU structural designFCU structural design

• 6 cameras

- 3 cameras for operation in the standard mode F/10 ( 2 - SFUV cameras, 1 - SFVIS camera);

- 3 cameras for operation in the long focus mode (f/50) (2 - LFUV cameras, 1 - SFVIS camera).

• Light-splitting unit;• FCU electronic subsystem (Module of Control and

Processing of Data, Power Supply Sources);• FCU structure, unifying all FC in the monoblock unit.

FCU featuresFCU features

• Spectral ranges:- UV 110 - 350 nm- visible 350 – 700 nm• Image quality- SFUV cameras, SFVIS camera 0.3 arc.sec;- LFUV camera, LFVIS camera 0.1 arc.sec.• Mass of each FC not higher than 1 kg • Power consumption 15 W of each FC not higher than• Maximal power consumption 50 W of the FCU not higher than

FCU accommodationFCU accommodation

Thermal environment of the field Thermal environment of the field camerascameras

• Operation temperature range, C +10 -- +30• Temperature range during assembling +18 -- +25 and tests• Temperature range during storage +5 -- +35 and transportation of the telescope • Critical temperature range -40 -- Toutgas

Toutgas should be defined

The Fine Guidance System - FGSThe Fine Guidance System - FGS

The concept: The FGS uses images of guiding stars from the T170M

telescopeFGS detectors are firmly attached to optical bench in the

nearest vicinity of the spectrographs entrance slits

The FGS consists of:• three identical detectors (CCD(?) + electronics)• common Data Processing Unit (DPU)• software including Master Catalogue

Spectrometerbase

Spectrometer slit

Area (cavity) for the guiding sensor

mounting

25

43.34

5

26

120

98

16

1617

13.3

13

22.7

34

68

16.5

A

AA-A

Detectors light-sensitive surface

Z

Y

FGS requirements • General: FOV and throughput should provide with

the capacity to detect at the level of S/N > 3 at least two guiding stars for the exposure time defined by angular velocity drift of the S/C

• Mass of sensor 0.25 kg• Power consumption of sensor 0.6 W not higher than• Mass of the Data Processing Unit 7 kg• Power consumption of the DPU 35 W not higher than

Thank you for your attentionThank you for your attention!!