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Solar Orbiter EUI Extreme UV Imager. SO Cleanliness Working Group #24 Stevenage 10 – 12 October 2017 Jean-Philippe Halain Udo Schühle (MPS). Outline. Summary of individual instrument status (including final bake-outs overview);
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Solar Orbiter EUIExtreme UV Imager SO Cleanliness Working Group #24 Stevenage 10 – 12 October 2017 Jean-Philippe Halain Udo Schühle (MPS)
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).
a) Summary of EUI project status + harness • EUI flight model
a) Summary of EUI project status • S/C activities • CEB • FM unit installed on S/C panel • PRT installed • S/C harness modified • Electrical tests to be performed • Harness • To be installed
a) Summary of EUI project status • S/C activities • OBS • Delivered to ADS in May 2017 • Pre-handover functional check OK, using FS CEB • Panel flatness checked (< 0.05 mm) • Handling jig fixation to OBS unit improved • Kapton collar installed on entrance baffles • Helicoils replaced by self-locking helicoils • Thermal straps installed on OBS interfaces • OBS mounted on platform • Harness fixation on OBS back panel to be performed • Alignment to be performed • Electrical tests to be performed
Cleanliness status • OBS cleanliness status (summary) • Cleanliness and Contamination Report • RP-CSL-SOEUI-17053, Iss. 1, Rev. 2 (11-05-2017) • MOC measured • After assembly: < 0,2 g/cm² • After TVAC / Bake-out: < 0,2 g/cm² • At delivery: < 0,2 g/cm² • PFO measured • At delivery 149 ppm (over 101 days) • Intermediate cleaning of internal cavity during assembly • External surfaces cleaned before delivery • Bake-out • 70°C for 72 hours • TQCM deviation of linearity (f”/f’) ~ 0,37% after 40 hours • RGA major peak (water) at 8x10-7 mbar partial pressure
Cleanliness status • OBS Assembly • Airborne counter log: ISO 5 conditions
Cleanliness status 10/01/2017 06/02/2017 06/03/2017 • OBS assembly • MOC witness sample monitoring: < 0,2 10-7 g/cm²
Cleanliness status 17/04/2017 • OBS TVAC • MOC witness sample monitoring: < 0,2 10-7 g/cm²
Cleanliness status • OBS bake-out • all sub-systems baked out before assembly • TQCM • Deviation of linearity (f”/f’) ~ 0,37% after 72 hours • RGA monitoring
Cleanliness status • OBS at delivery • PFO • 149 ppm over 101 days • Cleaned before delivery • MOC • << 40 ng/cm²
Cleanliness status • CEB cleanliness status • PFO • Build & test:10 ppm • Vacuum bake-out: 6 ppm • Packaging: 3 ppm • EMC test: 200 ppm (before cleaning outgoing inspection) • TVAC: 3 ppm • Total: 220 ppm • Bake-out • 80°C for 90 hours, • TQCM ≤1% outgassing deviation from linearity after 20 hours • RGA major peaks above 40AMU < 8.0x10-10 mbar partial pressure
Project status • CEB bake-out • TQCM • RGA
b) open issues affecting cleanliness Contamination analysis SOL.S.ASTR.RP.00037: Table 5.4: molecular contamination during ground tests: The EUI 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 1 ng/day.
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. • EUI exposed to UV are the Entrance Baffle and the Internal Doors surfaces. They are all made of aluminium. No 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. • EUI covers need to 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. • EUI contamination witnesses have been removed and analysed. Further monitoring to be made by 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