Orbiter contamination controls during maintenance down period: an approach for sensitive payloads

The orbiters undergo periodic maintenance during which extensive mechanical and electrical system inspection, upgrades and/or refurbishment are performed. For sensitive payloads, new materials added to the orbiter midbody (payload bay) area is of concern for the first flight after an orbiter maintenance down period (OMDP). Discovery, (OV- 103), recently underwent an OMDP, and the Hubble Space Telescope Servicing Mission 2 will be its first flight after OMDP. Due to the contamination sensitivity of the Hubble Space Telescope, a program was implemented to monitor the nonvolatile residue and particle levels of the midbody during the OMDP.