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MOTOROLA / COLLINS RADIO
Unified S-Band System
CommunicationsUnified Communications System● Retired (legacy architecture in use)
MASS
15 kg
POWER
20 W
REDUNDANCY
Dual-redundant
RAD HARDENED
Yes (for era)
FIRST USE
Nov 1967
Unified S-Band System is a communications system manufactured by Motorola / Collins Radio. It features dual-redundant redundancy.
ABOUT UNIFIED S-BAND SYSTEM
The Unified S-Band (USB) system was developed for the Apollo program to combine tracking, telemetry, command, and voice into a single S-band RF link. It revolutionized space communications by eliminating separate systems for each function. USB architecture influenced all subsequent NASA communication systems.
OPERATING PRINCIPLE
Single S-band carrier multiplexes voice, telemetry, ranging, and command via subcarrier modulation on 2.1 GHz
VEHICLES USING THIS SYSTEM
Apollo CSMApollo LMSkylab
SPECIFICATIONS
| CATEGORY | Communications |
| TYPE | Unified Communications System |
| MANUFACTURER | Motorola / Collins Radio |
| MASS | 15 kg |
| POWER CONSUMPTION | 20 W |
| REDUNDANCY | Dual-redundant |
| RADIATION HARDENED | Yes (for era) |
| ACCURACY | Range: 1 m at lunar distance |
| FIRST USE | November 9, 1967 |
| STATUS | Retired (legacy architecture in use) |
DETAILED SPECS
| FREQUENCY_GHZ | 2.1 |
| FUNCTIONS | Voice + TLM + CMD + Range |
| RANGE_KM | 400000 |
| HERITAGE | Apollo Program |
