Orbital Minotaur VI - Manual (Page 76)

Minotaur IV • V • VI User’s Guide Section 5.0 – Payload Interfaces
5.3.4. Payload Command and Control
The Minotaur standard interface provides discrete sequencing commands generated by the launch
vehicle’s Ordnance Driver Module (ODM) that are available to the payload as closed circuit opto-isolator
command pulses of 5 A in lengths of 35 ms minimum. The total number of ODM discretes is sixteen (16)
and can be used for any combination of (redundant) ordnance events and/or discrete commands
depending on the payload requirements.
5.3.5. Pyrotechnic Initiation Signals
Orbital provides the capability to directly initiate 16 separate pyrotechnic conductors through two
dedicated MACH Ordnance Driver Modules (ODM). Each ODM provides for up to eight drivers capable of
a 5 A, 100 ms, current limited pulse into a 1.5 ohm resistive load. All eight channels can be fired
simultaneously with an accuracy of 1 ms between channels. In addition, the ODM channels can be
utilized to trigger high impedance discrete events if required. Safing for all payload ordnance events will
be accomplished either through an Arm/Disarm (A/D) Switch or Safe Plugs.
5.3.6. Payload Telemetry
The baseline telemetry subsystem capability provides a number of dedicated payload discrete (bi-level)
and analog telemetry monitors through dedicated channels in the vehicle encoder. Up to 24 channels will
be provided with type and data rate being defined in the mission requirements document. The payload
serial and analog data will be embedded in the baseline vehicle telemetry format. For discrete monitors,
the payload customer must provide the 5 Vdc source and the return path. The current at the payload
interface must be less than 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 IV telemetry is subject to the provisions of the Strategic Arms
Reduction Treaty (START). START treaty provisions require that certain Minotaur vehicle 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 SDL. Encrypted
payload telemetry can be added as a non-standard service pending approval by SDL 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, Orbital provides three (3) separation loopbacks on the launch
vehicle side of the separation plane for positive payload separation indication.
The payload will provide two (2) 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 payload interface provides a 16 Kbps RS-422/RS-485 serial interface for payload
use with the flexibility to support a variety of channel/bit rate requirements, and provide signal
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