In order to meet project contamination cleanliness requirements, ground support equipment (GSE) used in clean areas at MSSL for flight hardware integration and testing needs to be cleaned at regular intervals. This is to ensure that surface contamination levels are minimized and the possibility of contamination redistribution from the GSE to the flight hardware is significantly reduced.
Required equipment
• Isopropyl Alcohol (IPA): Analar grade for course and intermediate cleaning and spectro grade for precision cleaning.
• Cleanroom Wipes: Lint-free Polyester
• Vacuum Cleaner: HEPA-filtered for precision cleaning
• Acetone: Analar grade for course and intermediate cleaning and spectro grade for precision cleaning
• Cleanroom Swabs: Woven Polyester
• Compressed Air or Nitrogen, filtered for particles to 0.5 micron
• White light source (100W)
Before use in a controlled clean area, GSE must be cleaned and inspected for visible cleanliness. GSE cleaning should be performed to visibly clean sensitive level (VC-S) as defined in MSSL/PA/PS/Q012. Procedure for verifying surfaces to a visibly clean level. To achieve this surface cleanliness standard, GSE cleaning should be performed in three stages as defined below:
Course cleaning - General
Course cleaning can be performed in non clean areas (workshop, office etc). The idea is to remove the bulk of contaminants from the hardware. Nitrile gloves should be worn during course cleaning
Intermediate cleaning - General
Intermediate cleaning should be performed in the anteroom. Particular attention should be paid to surfaces, crevices, corners, vents etc and these should be cleaned using appropriate solvents or detergents. A more thorough inspection of all surfaces is required at this stage. Cleanroom wipes and nitrile gloves should be worn while performing intermediate cleaning.
Precision cleaning - General
Precision cleaning should be performed inside the cleanroom but away from flight hardware (ideally at entrance to cleanroom). Spectro grade solvents should be used and polyester cleanroom wipes. Cleanroom dress code of mask, hood, cleanroom bunny suit, overshoes and nitrile gloves should be observed. A methodical and thorough surface inspection should be carried out as defined in MSSL/PA/PS/Q012 Procedure for verifying surfaces to a visibly clean level to a VC-S level after cleaning.
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