PHI Status Report SO Cleanliness Working Group #24 Stevenage 10 – 12 October 2017 Sandeep Ramanath & Udo Schühle (MPS) Udo Schühle, Sandeep Ramanath, SOCWG #24, Stevenage 10 - 12 October 2017

Outline Summary of individual instrument status (including final bake-outs overview); open issues affecting cleanliness and contamination, including evaluation of the impacts of the current Airbus contamination predictions; status of action items (including evidence of closure, where applicable).

SO/PHI instrument OPT-Unit ELE-Unit HEW-Unit, FEW-Unit, HAR-Unit (Harness)

Status of SO/PHI Analysis of FM calibration is ongoing FM O-Unit & E-Unit delivered to ADS Stevenage; mechanically and electrically integrated Entrance Windows (FEW & HEW): problems with windows originally foreseen as FMs. New coating process developed by contractor (Leonardo) Qualification successful New FM windows passed acceptance tests to be delivered on October 9th to TAS-I, for integration into Heatshield on October 16th, 2017

Status of SO/PHI Software onboard processing pipeline and flight control procedures are under development, first versions scheduled for end of 2017 Flight Spare PHI team is building a Flight Spare Model to serve as FS and Ground Reference Model all parts / subsystems fabricated and assembled assembly and integration of O-Unit & E-Unit ongoing, to be finalized by end of 2017

Cleanliness Status Cleanliness and Contamination Report released: SOL-PHI-MPS-AV7120-RP-1, Iss. 1, Rev. 2 (03-10-2017) Assembly in ISO-5 tent inside ISO-6 cleanroom MOC and PFO witness plates collected and analysed

ground tests and handling protection during ground tests witness plates during transportation

Cover foils used Three different types of antistatic foils /bags were used for maintaining the cleanliness of the unit. Llumalloy foil (23 microns) – These foils are thin and more flexible, They were used to a. Wrap the OPT unit (temp installation #-PHI-OU-01) b. Close the HRT Aperture (PHI-OU-02) c. Close the FDT apertures (PHI-OU-03). d. Cover the instrument during the vibration tests of OPT unit. Dunshield foil (SP06592; 50.8 micros) – because they are bit thicker, It was used for external covering of the unit during transportation and during test setup preparation for TV tests. Melinex Foil (111.7 Microns) - because of ‘no faraday cage effect’ It was used for EMC test. As the foil is thick and should not touch the hardware, a frame structure with POM-H were built around the unit with a gap of 50mm. The unit was purged with certified clean N2 gas.

Particulate Cleanliness Status PFO Witness Plates Exposed During AIT Phases

Particulate Cleanliness Status PFO WITNESS PLATES FOR DELIVERY

Molecular Cleanliness Status MOC WITNESS PLATES EXPOSED DURING AIT PHASES

Molecular Cleanliness Status MOC WITNESS PLATES EXPOSED DURING AIT PHASES MOC WITNESS PLATES FOR DELIVERY

Cleanliness Status - NCRs LIST OF NCRS RELATED TO CONTAMINATION

Bake outs All parts have been baked out on oven before assembly

Bake outs (1) All sub-units (OPT, ELE, Harness, HEW, FEW) have been baked with TQCM PHI OPT- and ELE-Units were baked out together at 70°C with TQCM (report SOL-PHI-MPS-PA1100-RP-1)

Bake outs (2) PHI Harness was baked out at 80°C with TQCM (report SOL-PHI-MPS-PA1100-RP-1)

Bake outs (3) PHI HEW and FEW have been baked out with TQCM and subjected to T> 200°C during TV tests (see report SOL-PHI-MPS-PA1100-RP-2 and SOL-PHI-INTA-HW5500-RP-19)

b) open issues affecting cleanliness Contamination analysis SOL.S.ASTR.RP.00037: Table 5.5: molecular contamination during ground tests: The PHI EBOX EXT and PHI OPT EXT HW sensitive surfaces are inside the S/C cavity which should accumulate MOC at a predicted rate of 0.2 ng/day, while the table shows no MOC values.

c) status of action items AI#22: Airbus-DS, ESA and instruments teams to review which materials may need to be tested. The solar array CDR is scheduled for June 2017. PHI surfaces exposed to UV are the Entrance Windows (HEW and FEW). They have been tested. No further test required. AI#24: Airbus DS plans to remove instruments covers during TV activities. Instruments teams to check compatibility of covers’ materials with thermal vacuum conditions if covers need to be maintained. PHI covers of the HEW and FEW will be removed before TV test. AI#26: Instruments teams to provide relevant information on frequency of measurements and handling of contamination witnesses at Airbus DS. PHI has not supplied any witness samples for use during AIT at Airbus DS. Δ-CDR AI#1: ESA to ensure that each instrument PI will need to study the updated SOL.S.ASTR.RP.00037 and the impact of the spikes on their instruments and implement operational constraints in their instrument user manual. open