LISSA FM Sun Sensor Performance Test 

Introduction

Test Description: Test the functionality and performance of flight model sun sensors. This test is based off of the sun sensor calibration procedure provided by the York University Nanosat Research Laboratory for the Iris mission.

Completed: 

Documented by: Riley Sweeney

Resources Required:

• Tools: M1 screws and driver, small flathead screwdriver, 1.5mm hex driver

• Hardware and Equipment: 2x UMS-0381 FM, UMS-0866 ADCS FM CCA, programmable power supply, rotation table, UMS-1076 LED driver, UMS-1077 LED source, UMS-1078 lightguide adapter, UMS-1079 LED lightguide, UMS-1080 lightguide collimator

• PPE: FM testing will likely occur in the clean room. Please follow all clean room safety guidelines. Please wear an ESD bracelet and use ESD mat when working with electronics.

Verification Activities: R-LIB-ADC-033-6974

Pass Criteria: The sun sensors shall be able to determine the direction of a light source to within 1 degree.

Test Apparatus

This test will use the FM FlatSat.

1. Check the connections between PCBs on the FlatSat. The power PCB should be connected to a power supply with two wires for power and ground. This PCB should also connect to CDH using an intermodular connector.

2. The CDH PCB should have two intermodular connectors, one coming from the Power PCB, and one going to the AODCS PCB.

3. Sun sensor connects to the AODCS PCB using a ten pin connector. There are two ports on the PCB, SUN_SENSOR_1 and SUN_SENSOR_2. It is recommended that the first sun sensor test use SUN_SENSOR_1, and the second test use SUN_SENSOR_2.

Test Set-Up

Setting up the collimated LED assembly:

1. Configure the DIP switches on UMS-1076 for manual knob control and a max current of 350 mA.

2. Connect the red wire from UMS-1077 to LED+ on UMS-1076, and the black wire to LED-. Tighten the set screws using a small flathead screwdriver to secure the connection.

3. Thread UMS-1078 onto the end of UMS-1077. Be careful not to touch the lens on either component.

4. Insert one end of UMS-1079 into UMS-1078. Gently tighten the set screw using a 1.5 mm hex driver.

5. Insert the other end of UMS-1079 into UMS-1080. Gently tighten the set screw using a 1.5 mm hex driver.

Setting up the calibration table:

1. Mount the sun sensor to the calibration table using two M1 screws.

2. Set the LED holder to -30 degrees to begin taking measurements.

3. Turn on the LED, and ensure the light is illuminating both slits on the sun sensor mask.

Test Procedures

1. Take the first measurement when you are ready. Document the two results from 'AngleDecompose'.

2. Rotate the LED by one degree and repeat step 4, from -30 to +30 degrees, the full field of view of the sensor.

3. Detach the sun sensor, rotate it 90 degrees and remount it.

4. Redo these steps in the new sun sensor orientation.

Test Close-Out

Include information about apparatus tear down, clean up, consumables storage, and how to store test data.

Data Analysis

Provide step-by-step instructions for data analysis, including location of data storage.