Orbital Minotaur VI - Manual (Page 60)

Minotaur IV • V • VI User’s Guide Section 4.0 – Payload Environment
4.8. Payload Electromagnetic Environment
The payload Electromagnetic Environment (EME) results from two categories of emitters: Minotaur
onboard antennas and Range radar. All power, control and signal lines inside the payload fairing are
shielded and properly terminated to minimize the potential for Electromagnetic Interference (EMI). The
Minotaur payload fairing is Radio Frequency (RF) opaque, which shields the payload from external RF
signals while the payload is encapsulated.
Table 4.8-1 lists the frequencies and maximum radiated signal levels from vehicle antennas that are
located near the payload during ground operations and powered flight. The specific EME experienced by
the payload during ground processing at the PPF and the launch site will depend somewhat on the
specific facilities that are utilized as well as operational details. However, typically the field strengths
experienced by the payload during ground processing with the fairing in place are controlled procedurally
and will be less than 2 V/m from continuous sources and less than 10 V/m from pulse sources. The
highest EME during powered flight is created by the C-Band transponder transmission, which results in
peak levels at the payload interface plane of 25.40 V/m at 5765 MHz. Range transmitters are typically
controlled to provide a field strength of 10 V/m or less inside the fairing. This EME should be compared to
the payload’s RF susceptibility levels (MIL-STD-461, RS03) to define margin.
Table 4.8-1. Minotaur IV Launch Vehicle RF Emitters and Receivers
SOURCE 1 2 3 4 5 6 7 8
Function
Command
Destruct
Tracking
Transponder
Tracking
Transponder
Launch
Vehicle
Enhanced
Instrumentation
Telemetry
(Optional)
GPB A GPB B GPB
Receive/
Transmit
Receive Transmit Receive Transmit Transmit Transmit Transmit Receive
Band UHF C-Band C-Band S-Band S-Band S-Band S-Band
L-Band
(L1/L2)
Frequency (MHz) 421 5765 5690 2240.5 2285.5 2260.5 2270.5
1575.42 /
1227.6
Bandwidth N/A 14 MHz 14 MHz 1.78 MHz 1.78 MHz 256 kHz 256 kHz
20.46 MHz
(P(Y) Code)
Power Output N/A 400 W (peak) N/A 10 W 10 W 5 W 5 W N/A
Sensitivity -107 dBm -70 dBm -70 dBm N/A N/A N/A N/A -123 dBm
Modulation Tone Pulse Code Pulse Code PCM/FM PCM/FM PCM/FM PCM/FM
Spread
Spectrum
QPSK
Field Strength at
Fwd Edge of the
Payload Adapter
Cone
N/A
1.99 V/m avg
(25.40 V/m per
0.5μs pulse)
N/A <11 V/m <11 V/m <6 V/m <6 V/m N/A
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