Orbital Minotaur I - Manual (Page 55)

Minotaur I User’s Guide Section 5.0 – Payload Interfaces
10 mA. Separation breakwire monitors can be specified if required. The number of analog channels
available for payload telemetry monitoring is dependent on the frequency of the data. Payload telemetry
requirements and signal characteristics will be specified in the Payload ICD and should not change once
the final telemetry format is released at approximately L-6 months. Orbital will record, archive, and reduce
the data into a digital format for delivery to the payloaders for review.
Due to the use of strategic assets, Minotaur I telemetry is subject to the provisions of the START treaty.
These provisions require that certain Minotaur I telemetry be unencrypted and provided to the START
treaty office for dissemination to the signatories of the treaty. The extent to which START applies to the
payload telemetry will be determined by SD. Encrypted payload telemetry can be added as a non-
standard service pending approval by SD and the START treaty office.
5.3.7. Payload Separation Monitor Loopbacks
Separation breakwire monitors are required on both sides of the payload separation plane. With the
Orbital provided separation systems, Minotaur I provides three separation loopbacks on the launch
vehicle side of the separation plane for positive payload separation indication.
It is a Launch Vehicle requirement that the payload provide two separation loopback circuits on the
payload side of the separation plane. These are typically wired into different separation connectors for
redundancy. These breakwires are used for positive separation indication telemetry and initiation of the
C/CAM maneuver.
5.3.8. Telemetry Interfaces
The standard Minotaur I payload interface provides a 16Kbps RS-422/RS-485 serial interface for payload
use with the flexibility to support a variety of channel/bit rate requirements, and provide signal
conditioning, PCM formatting (programmable) and data transmission bit rates. The number of channels,
sample rates, etc. will be defined in the Payload ICD.
5.3.9. Non Standard Electrical Interfaces
Non-standard services such as serial command and telemetry interfaces can be negotiated between
Orbital and the payload provider on a mission-by-mission basis. The selection of the separation system
could also impact the payload interface design and will be defined in the Payload ICD.
5.3.10. Electrical Launch Support Equipment
Orbital will provide space for a rack of customer supplied EGSE in the LCR, and/or the on-pad Launch
Equipment Vault (LEV). The equipment will interface with the launch vehicle/spacecraft through either the
dedicated payload umbilical interface or directly through the payload access door. The payload customer
is responsible for providing cabling from the EGSE location to the launch vehicle/spacecraft.
Separate payload ground processing harnesses that mate directly with the payload can be
accommodated through the payload access door(s) as defined in the Payload ICD.
Release 3.0 March 2014 42