Orbital Antares - Manual (Page 40)

Antares
®
OSP-3
User’s Guide
Section 4.0
– Payload Environments
Release 1.1 July 2013 29
4.4. Contamination and Environmental Control
Orbital understands the importance of maintaining proper thermal and contamination control and is com-
mitted to providing environments that meet customer requirements. Orbital partners with each USAF
payload customer to ensure the required payload environments are identified and maintained at all times.
Orbital has developed a general environmental control plan for all Antares missions. This plan is tailored
for each mission to capture the unique environmental control requirements of each payload.
Prior to payload enclosure, payload thermal and humidity environments are maintained by the HIF facility
ECS. Once enclosed, payload environments are maintained by either the PECS or the Pad ECS. The
Pad ECS maintains the payload thermal and humidity environments through launch. Each of these sys-
tems control temperatures between 15.5
– 25.5 °C (60 – 80 °F) and humidity between 30 to 60%.
4.4.1. Ground Transportation Environments
Environmental control during Antares payload transport activities is maintained by the PECS. The PECS
is a trailerized, self-
contained environmental control system. The system’s two independent refrigeration
circuits cool and dehumidify incoming air after which the air is reheated to maintain the desired tempera-
ture and Relative Humidity (RH) setpoints. A humidifier is available to add moisture, if needed. The
PECS continuously purges the fairing environment with clean filtered air providing a Class 8 (IAW ISO
14644) or better environment during all post-
encapsulation operations. Orbital’s PECS incorporates both
a HEPA filter unit for particulate control and carbon filtration for hydrocarbon control. Conditioned air fil-
tration removes 99.97% of all particles with a size greater than 0.3 microns and 95% of all hydrocarbons
of molecular weight greater than 70.
4.4.2. Launch Operations Fairing Environment
Once the TEL with the integrated Antares launch vehicle has been secured to the launch pad mount, the
fairing air supply is transitioned from the PECS to the pad ECS. During this transition, a short disruption
of airflow to the fairing occurs; however, no perceptible changes in the environment are anticipated. The
pad ECS then continues to maintain fairing environment control throughout the remainder of the launch
operations. Backup power is implemented at the launch site to ensure payload environment controls are
maintained at all times.
4.4.3. Contamination Control
Orbital’s Antares contamination control program is designed to minimize the payload’s exposure to con-
tamination from the time the payload arrives at the payload processing facility through orbit insertion and
separation. The contamination control program, based on industry standard contamination control speci-
fications, ensures that all personnel and processes strictly adhere to payload cleanliness requirements.
During all payload integration procedures in the HIF, the payload is maintained in a Class 8 or better
cleanliness environment at all times through the use of a clean tented area forward of the payload adap-
ter. Once the payload is enclosed, the air entering the fairing is also maintained to Class 8 or better
cleanliness environment at all times through HEPA and carbon filtered air removing 99.97% off all par-
ticles with a size greater than 0.3 microns and 95% of all hydrocarbons of molecular weight greater than
70.
The internal surfaces of the Antares payload fairing and payload adapter are cleaned, certified, and main-
tained to visibly clean, Level II or better. The Antares avionics section, Stage 2 motor, and separation