Orbital Minotaur I - Manual (Page 77)

Minotaur I User’s Guide Section 8.0 – Optional Enhanced Capabilities
8.6. Enhanced Contamination Control
To meet the requirement for a low contamination
environment, Orbital uses existing processes
developed and demonstrated on the Minotaur and
Pegasus programs. These processes are designed
to minimize out-gassing, supply a Class 10,000
clean room environment, assure a high cleanliness
payload envelope, and provide a HEPA-filtered,
controlled humidity environment after fairing
encapsulation. Orbital leverages extensive payload
processing experience to provide flexible,
responsive solutions to mission-specific payload
requirements (Figure 8.6-1).
8.6.1. Low Outgassing Materials
Orbital’s existing high cleanliness design and
integration processes ensure that all materials
used within the encapsulated volume have
outgassing characteristics of less than 1.0% Total
Mass Loss (TML) and less than 0.1% Collected
Volatile Condensable Mass (CVCM) in accordance
with ASTM E59. If materials within the
encapsulated volume cannot meet low outgassing
characteristics because of unique mission
requirements, a contamination control plan is
developed to ensure controls are in place to
eliminate any significant effect on the payload.
8.6.2. High Cleanliness Integration Environment
With the enhanced contamination control option, the encapsulated payload element of the vehicle is
processed in an ISO Standard 14644-1 Class 10,000 environment during all payload processing activities
up to fairing encapsulation (ISO 7). The PPF clean room utilizes HEPA filtration units to filter the air and
ensure hydrocarbon content is maintained at ≤15 ppm, with humidity maintained at 30-60% relative
humidity. Depending on payload requirements, the clean room can also be certified as Class 100,000
(ISO 8) while still providing tighter environmental control than the standard high-bay environment, thereby
streamlining access and payload processing.
8.6.3. HEPA-Filtered Fairing Air Supply
With the enhanced contamination control option, the ECU continuously purges the fairing volume with
clean filtered air while maintaining temperature, humidity, and cleanliness. Orbital’s ECU incorporates a
HEPA filtration unit along with a hydrocarbon filter adaptor to provide Class 10,000 (ISO 7) air and ensure
hydrocarbon content is maintained at ≤15 ppm, with humidity maintained as stated in section 4.6.1.
Orbital monitors the supply air for particulate matter via a probe installed upstream of the fairing inlet duct
prior to connecting the air source to the payload fairing.
Figure 8.6-1. Minotaur Team Has Extensive
Experience in a Payload Processing Clean
Room Environment
Release 3.0 March 2014 64