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Alpha Magnetic Spectrometer – 02

Phase III Flight Safety

UPS Overview

Jan 12 2010

John A. Heilig ESCG/Jacobs

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Alpha Magnetic Spectrometer – 02Uninterruptible Power Supply (UPS)

• The UPS system consists of a redundant set of Lithium-Ion batteries (2 independent 8 cell units)

• To ensure mission success during loss of ISS power or communication, the UPS battery provides control power to the payload for:– Watch-dog timer/control circuit– Quench monitoring– Initiation of quench heater 45A pulse– Nominal ramp-down at the end of the eight hours.– CPVS Solenoid valve operations

• Are sized for a minimum of 8 hours of operation, plus assisted quench operation / ramp down

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Alpha Magnetic Spectrometer – 02Uninterruptible Power Supply (UPS)

• Battery is designed to meet:– NSTS 1700.7B, “Safety Policy and Requirements For Payloads Using

the Space Transportation System”– NSTS 1700.7B ISS Addendum, “Safety Policy and Requirements For

Payloads Using the International Space Station”– JSC 20793, “Manned Space Vehicle Battery Safety Handbook”

• JSC EP3 Battery Safety Form – Rev C

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Alpha Magnetic Spectrometer – 02CAB to UPS Block Diagram

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Alpha Magnetic Spectrometer – 02UPS Battery

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Alpha Magnetic Spectrometer – 02Uninterruptible Power Supply Components

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Alpha Magnetic Spectrometer – 02UPS Battery “Bricks” (old cells)

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Alpha Magnetic Spectrometer – 02UPS Battery Management System (BMS)

• BMS is a radiation tolerant circuit that monitors and maintains a series string of eight Li-ion battery cells, with a nominal output voltage of 32VDC.

• The battery is monitored for unhealthy temperature and/or electrical conditions, upon which the system reacts to protect the cells.– Automatic Cell Balancing– Thermal Monitoring– Over-discharge Monitoring– Short Circuit Protection– Cell Over-voltage Monitoring

• BMS consists of three PCBs:– Master Control Board– QTY 2 Monitor/Equalizer boards

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Alpha Magnetic Spectrometer – 02UPS BMS Electronics

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• While in testing by AMS-02 Collaboration personnel, the QM UPS suffered a catastrophic failure due to improper test setup and monitoring.

• After a failure investigation with the AMS-02 collaboration testing partner, MIT pulled the contract for continued assembly and testing of the UPSs and awarded it to Yardney Technical Products, the original battery cell manufacturer and a leader in the field.

Alpha Magnetic Spectrometer – 02 Current Status

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• Upon receipt of the 4 remaining UPS units, an incoming inspection by Yardney noted that multiple cells in the units shows signs of decreased capacity. No obvious cause could be determined by observation or testing of the UPSs, BMSs, or cells.

• It is strongly suggested the cause of the cell capacity issue was improper handling and storage before being received by Yardney.

Alpha Magnetic Spectrometer – 02 Current Status

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• Due to the low capacity, the decision was made to remanufacture identical cells to repopulate the entire set of flight and flight spare UPSs (8 cells x 4 units) and perform Protoflight testing on these cells. This cell design was Qual and Acceptance tested originally per L1135-05, Qualification Test Report for the Alpha Magnetic Spectrometer-02 (AMS-02) Uninterruptible Power Source (UPS) NCP25-3 Lithium-ion Cells Per LiTP-6208 Test Dates 1~05 to 2/17/05, Rev. -, Dated 3/11/2005

• The four (4) UPS units, 2- FL, 2- FS are being assembled now and will be fully flight certified.

• During integrated testing of the Flight Spare units, issues were discovered with one FET and resistance drift on thin film resistors on the BMS circuits. Components replaced.

Alpha Magnetic Spectrometer – 02 Current Status

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Alpha Magnetic Spectrometer – 02 Current Status

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Alpha Magnetic Spectrometer – 02 Current Status

NCP25-3 AMS-02 Cell Score for Unit Grouping

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Alpha Magnetic Spectrometer – 02 Current Status

• Flight Spare and Flight Unit UPSs are currently in assembly and Test at Yardney.

• Uncertified (partially) Flight Spare units will be used at ESTEC for TVT testing

• FS units will be replaced with fully certified Flight units upon arrival at KSC.

• FS units will be returned to Yardney to complete Flight certification

• Delivery of two (2) FS units is expected Jan 15 and two (2) Flight units will be delivered to KSC by the end of Mar ‘10.

• Full details of the UPS are included in the Safety Data Package– Section 5.12.4.2 Cryomagnet Control and

Signal Conditioning (CCSC)– Section 5.12.4.4 Cryomagnet Self Protection

(CSP) – Section 5.12.4.5 CSP Uninterruptible Power

Source (UPS)– Hazard Report 13 –Battery Failure

(Leakage/Rupture)

Alpha Magnetic Spectrometer – 02 Conclusion