Orbital Minotaur I - Manual (Page 54)

Minotaur I User’s Guide Section 5.0 – Payload Interfaces
Figure 5.3.1-1. Payload Umbilical 1:1 Pin Outs
5.3.2. Payload Interface Circuitry
Standard interface circuitry passing through the payload-to-launch vehicle electrical connections are
shown in Figure 5.3-1. This figure details the interface characteristics for launch vehicle commands,
discrete and analog telemetry, separation loopbacks, pyro initiation, and serial communications interfaces
with the launch vehicle avionics systems.
5.3.3. Payload Battery Charging
Orbital provides the capability for remote controlled charging of payload batteries, using a customer
provided battery charger. This power is routed through the payload umbilical cable. Up to 5.0 amperes
per wire pair can be accommodated. The payload battery charger should be sized to withstand the line
loss from the LEV to the spacecraft.
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 SV requirements.
5.3.5. Pyrotechnic Initiation Signals
Orbital provides the capability to directly initiate 16 separate pyrotechnic conductors through two
dedicated MACH ODMs. 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 SV 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 SV serial
and analog data will be embedded in the baseline vehicle telemetry format. For discrete monitors, the SV
must provide the 5 Vdc source and the return path. The current at the payload interface must be less than
Release 3.0 March 2014 41