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Update space_optics_cleaning.md
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douglase authored Apr 21, 2024
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Expand Up @@ -15,10 +15,10 @@ Gushwa, K. E., & Torrie, C. I. (2014). Coming clean: understanding and mitigatin
MEMS devices and optical components are particularly susceptible to contamination, thus:

* payload assembly will occur in a class 100,000 or better cleanroom
* installation and removal operations on the exposed deformable mirror (with window removed) will occur under a class 1000 or better flow bench
*do not use alcohol to clean the aluminum mirrors* [it reacts with the Al](Cleaning%20Optics-%20Choosing%20the%20Best%20Meth...ptical%20components%20%7C%20Photonics%20Handbook.pdf) and they have been cleaned at the factory.
* installation and removal operations on an exposed MEMS device will occur under a class 1000 or better flow bench
* do not use alcohol to clean aluminum mirrors* [it reacts with the Al](Cleaning%20Optics-%20Choosing%20the%20Best%20Meth...ptical%20components%20%7C%20Photonics%20Handbook.pdf) and they have been cleaned at the factory.
* Only low-out-gassing (per https://outgassing.nasa.gov) lubricants (e.g. Bray-Coat) and adhesives (e.g. 2216 A/B Gray) will be used in the payload
* guided by NASA STD 8739-1 (WORKMANSHIP STANDARD FOR STAKING AND CONFORMAL COATING OF PRINTED WIRING BOARDS AND ELECTRONIC ASSEMBLIES, https://snebulos.mit.edu/projects/reference/NASA-Generic/NASA-STD-8739-1.pdf) Electrical components will be cleaned as appropriate and conformal coated where possible (the DM wirebonds cannot be coated)
* guided by NASA STD 8739-1 (WORKMANSHIP STANDARD FOR STAKING AND CONFORMAL COATING OF PRINTED WIRING BOARDS AND ELECTRONIC ASSEMBLIES, https://snebulos.mit.edu/projects/reference/NASA-Generic/NASA-STD-8739-1.pdf) Electrical components will be cleaned as appropriate and conformal coated where possible (e.g. wirebonds cannot be coated)

### Cleaning plan
* Machined and 3D printed parts in view of payload optical components will be ultrasonically cleaned in 4 steps:
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The payload is extremely sensitive to the conflicting hazards of electrostatic discharge and high humidity, requiring

* humidity monitoring of the spacecraft during integration
* DM operation limited to humidities between 25 \%RH and 40 \%RH (25-30 \%RH preferred)
* MEMS de operation limited to humidities between 25 \%RH and 40 \%RH (25-30 \%RH preferred)
* technician payload handling of the powered off payload at $>40$\%RH is preferred for ESD hazard reduction.
* Payload and technician grounding at all times
* Daily testing of grounding equipment
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