DISTRIBUTION LIST. Others original copies Name amount. Lens Research & Development 1x Uittenhout, J.M.M. 1x DOCUMENT CHANGE RECORD

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2 2 of 15 DISTRIBUTION LIST Others original copies Name amount Lens Research & Development 1x Uittenhout, J.M.M. 1x DOCUMENT CHANGE RECORD Issue Date Total pages Pages affected Brief description of change All First issue of document 1a All Requirements numbered, measured data removed Non calibrated accuracy changed from 2.5 3σ to 3.5 3σ Maximum voltage case to ground added Thermal vacuum test added Minimum dark current resistance added 2a Removed Typo. instead of, 2b Bleed resistance value changed 2c , d All BiSon64 picture changed Reference frame drawing added BiSon64 equation added Pyro shock 10000g added Removed typo s 2e , 8 New equation & visualization reference frame 2f , 8 Update α and β angles fig 1 & , 12 Update Electrical interface & eigenfrequency 15 7 Removed Typo (caption reference)

3 3 of 15 Contents APPLICABLE DOCUMENTS... 4 REFERENCE DOCUMENTS INTRODUCTION SOLAR DIRECTION ANGLES THE REFERENCE FRAME MECHANICAL INTERFACES REPEATABILITY OF MOUNTING FASTENING TORQUE MASS CENTRE OF GRAVITY OPTICAL INTERFACES ELECTRICAL INTERFACES GROUNDING AND ISOLATION CONDUCTIVITY OF EXTERNAL SURFACES SPECIFIED ACCURACY ENVIRONMENTAL SPECIFICATIONS STORAGE CONDITIONS OPERATING TEMPERATURE RANGE NON-OPERATING TEMPERATURE RANGE TEMPERATURE CYCLING VIBRATION SPECIFICATIONS Eigenfrequency Sine vibration Random vibrations Shock specification PIND testing COSMIC RADIATION RESISTANCE... 15

4 4 of 15 Applicable documents Nr Document number Document name Issue [AD1] 100B502 BiSon64 interface control drawing 01C [AD2] 500M010 Precision fastener 00 [AD3] 500M011 Washer 00 Reference documents Nr Document number Document name Issue

5 5 of 15 Abbreviations AD ADC CoG COTS CTE DNL EMC FOV ICD LISN LOS NTC PIND PSD RD RMS TBV Applicable Document Analogue to Digital Converter Centre of Gravity Commercial Off The Shelf Coefficient of Thermal Expansion Differential Non Linearity Electro Magnetic Compatibility Field of View Interface Control Document Line Impedance Stabilization Network Line Of Sight Negative Temperature Coefficient resistor (thermistor) Particle Induced Noise Detection Power Spectral Density Reference Document Root Mean Square To be validated (tests still need to be performed) List of photos Photo 1 BiSon64 Sunsensor... 6 List of figures Figure 1 α and β angle visualization (to be addd as a figure caption!)... 7 Figure 2 α and β reference frame and angle definition... 8 Figure 3 Random vibration profile Figure 4 Pyro shock spectrum specified List of tables Table 1 Thermal cycling specification Table 2 Sine vibrations Table 3 Random vibrations Table 4 Pyro shock specification V Table 5 Pyro shock specification V List of equations Equation 1 BiSon64 α and β formulas... 7

6 6 of 15 1 Introduction The BiSon64 sunsensor is a high reliability sunsensor with a nominal field of view of 64 degrees in diagonal which is specifically designed for demanding satellite applications. This document shall be read in conjunction with the interface control drawing [AD1]. The levels given in this document are properties after the given environmental tests have been applied. Photo 1 BiSon64 Sunsensor

7 7 of 15 2 Solar direction angles 2.1 The reference frame Apart from the quadrant definition as given in [AD1] it is necessary to define the reference frame of the sunsensors in order to avoid sign errors in the attitude control subsystem. All BiSon64 sunsensors use the reference angles definition given in Figure 2. The angles are illustrated schematically in Figure 1. These diagrams provide the definitions of the projected solar zenith angles α and β (the angle ξ is the solar zenith angle with respect to the sunsensor s normal axis). The projected angles α and β are to be calculated by means of Equation 1. In Figure 2 both, α and β are positive. Note that the angles α and β are pointing towards the solar illumination direction. All BiSon64 sunsensors require the formulas as given in Equation 1 to calculate the solar zenith angles α and β. The angles α and β are located in the planes spawn by the axis y-z and x-z, respectively.. S a = Q 1 + Q 4 Q 2 Q 3 = tan(α) Q 1 + Q 2 + Q 3 + Q 4 tan(α max ) S b = Q 1 + Q 2 Q 3 Q 4 = tan(β) Q 1 + Q 2 + Q 3 + Q 4 tan(β max ) Equation 1 BiSon64 α and β formulas Figure 1 α and β angle visualization (to be added as a figure caption!)

8 8 of 15 Figure 2 α and β reference frame and angle definition

9 9 of 15 3 Mechanical interfaces The dimensions of the mechanical interfaces are given in [AD1] the actual reference of the sensor is formed by the line through the center of the two lower mounting holes. The actual reference hole is the right lower hole which has a H7 fit and defines the position of the sensor sensitive surface. The left lower hole is a slotted hole (see detail Z) which defines the rotation around the reference hole. The third hole is merely for ensuring the sensor is mounted flat on the surface. 3.1 Repeatability of mounting Req The repeatability of mounting shall be better than 0.15 degrees. When using the prescribed mounting hardware This can be improved upon by using mounting hardware with a lower mechanical tolerance down to 0.05 degrees.( for fasteners with 0 µm tolerance on the shaft) 3.2 Fastening torque The special fasteners defined in [AD2] shall be fastened with a torque of 1Nm ± 10%. The M4 fastener used for the oversized hole shall be fastened with a torque between 0.63Nm and 1.5Nm (consequently 1Nm ± 10%) can be used for all three bolds. 3.3 Mass Req The mass of the unit is approximately 22 grams but more accurately given on page 1 of [AD1]. 3.4 Centre of gravity The center of gravity is given on page 1 of [AD1]. But there are no requirements on the CoG. 4 Optical interfaces The optical interfaces are defined on page 2 of [AD1] in combination with the reference frame definition as given in par 2. Req. 4-1 The field of view of the sensors shall be >±62 in both diagonals (124 in full FOV).

10 10 of 15 5 Electrical interfaces The electrical connections are as given on page 3 of [AD1]. The sensor will generate 4 analogue currents. Req. 5-1 Req. 5-2 Req. 5-3 Req. 5-4 The currents generated shall be 1.45mA ±20 % at normal incidence and 20 C ± 5 C. The generated currents shall be 1.75mA ±20 % maximum and 20 C ± 5 C. The currents generated shall be 1.45mA ±40 % at normal incidence over the full temperature range. The generated currents shall be <2.5mA maximum over the full temperature range. These values are at 1 AM(0) sun illumination and 0 bias (measured with a transimpedance amplifier) over the full temperature range. Req. 5-5 Req. 5-6 Each diode shall have a dark current resistance of >10MΩ at a reverse bias voltage of 10V. The internal thermistor shall have a nominal value of 10kΩ ± 25 C. 5.1 Grounding and isolation Req The resistance from the common ground to case shall be 1MΩ<R<10MΩ. Req The capacitance between the sensor and ground shall be <100pF. Req The voltage withstanding capability between the ground and case shall be >50V. 5.2 Conductivity of external surfaces Req In order to avoid build-up of electrical charge, the electrical conductivity of the external surfaces (including the sapphire window) shall be better than 10kOhm. 5.3 Specified accuracy Req The specified accuracy for the sensors is better than 3.5 degrees 3σ if no calibration table is used. Req The specified accuracy for the sensors is better than 0.5 degree 3σ if a calibration table is used. For this accuracy to be reached the readout electronics shall have An offset of < 1mV per channel at a full scale of 10V. 12 bit accuracy. Inter channel gain equality of better than 0.1%.

11 11 of 15 6 Environmental specifications 6.1 Storage conditions Sensors should be stored in a dust free, dry and temperature controlled environment with a temperature range of 0 C to +30 C and a relative humidity of 20% to 80% storage lifetime under these conditions is longer than 5 years when kept in the original packaging. 6.2 Operating temperature range Req The sensors shall perform within specifications when operated in the range of -40 C to +80 C. 6.3 Non-operating temperature range Req The sensors shall survive a non-operating temperature range of -45 C to + 85 C. 6.4 Temperature cycling The sensors used for qualification have shown to meet the following temperature cycling requirements during qualification testing. Req. Conditions Temperature range Number of cycles Burn in 1) Full range high rate thermal cycle in gaseous nitrogen -45 C..+85 C -40 C..+80 C High rate thermal vacuum test in Virac facility at ESTEC 2) C Double sine thermal cycles -20 C..+60 C with ±20 C variation Table 1 Thermal cycling specification 10 (performed on each sensor) (TBC) 3) 1) As part of the acceptance test procedure a 10 cycle burn in test is performed according to MIL- STD-883 M method 1010 B before final electrical measurements and visual inspection. For these cycles the temperature range shall be as specified. 2) Thermal vacuum testing at the Virac facility of ESTEC have been performed where the sensors were taken from sun illuminated (by means of a solar simulator) to cryogenic temperatures (liquid nitrogen dewar). These tests were performed on the same devices that were put through the 1000 gaseous nitrogen thermal cycles.

12 12 of 15 3) Tests performed with high number of cycles don t stack, so either the 1000 full range cycles or the double sine test shall be performed. 6.5 Vibration specifications Vibration specifications of the sensors are given below. It should be noted that these are qualification levels and sensors are actually tested to these levels. Any safety margins required for the mission shall therefore be subtracted from the given level to see if the sensors meet mission requirements. The sine and random qualifications have been performed using the in [AD2] and [AD3] defined hardware and torqued to 1Nm ± 10% Eigenfrequency Req The first eigenfrequency shall be >500Hz Sine vibration Req The sensors shall be able to function properly after being subject to vibration test levels specified in Table 2 in all three axis. Sine vibrations Frequency (Hz) Level mm peak to peak g 1 octave/minute 1 sweep up/1 sweep down Table 2 Sine vibrations

13 13 of Random vibrations Req The sensors shall be able to function within specifications after being subject to vibration test levels specified in Table 3 in all three axis. Frequency Hz Random vibrations PSD g²/ Hz dB/oct dB/oct RMS level g Duration 180 seconds Table 3 Random vibrations Figure 3 Random vibration profile

14 14 of Shock specification Req The sensors shall be able to function within specifications after being subject to Pyro shock test levels specified in Table 4 in all three axis. Pyro shock Frequency Level Hz g shocks in any direction Table 4 Pyro shock specification V1 Figure 4 Pyro shock spectrum specified

15 15 of 15 The sensors shall be able to function within specifications after being subject to Pyro shock test levels specified in Table 5 in all three axis. Frequency Hz Pyro shock Level g shocks in any direction Table 5 Pyro shock specification V PIND testing Req The sensors shall be able to function within specification after being subject to a PIND test (Particle Induced Noise Detection) according to MIL-STD-883 Method 2020 A. 6.6 Cosmic radiation resistance Req The sensors shall be able to function within specification after 1Mrad(Si) total dose irradiation at bare diode level. 1) 1) This is to be verified by irradiating the bare diodes up to 1Mrad(Si)