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GPS Programs

GPS Launch Anomaly and Disposal Operations (LADO) System (13 Years)

In 2002, the GPS Wing started developing LADO as its replacement for mainframe-based Air Force Satellite Control Network (AFSCN) Command and Control System (CCS). LADO is based on Braxton Technologies ACE Premier™ commercial satellite ground system product line. LADO consists of three major functions: 1) Telemetry, Tracking and Control (TT&C), 2) Mission Planning, and 3) LADO Simulation. The TT&C provides the commanding of the satellite(s), sending and receiving telemetry as well as tracking data. Mission Planning is responsible for the planning and execution of satellite maneuvers during launch and early orbit (LEO), anomaly resolution and disposal activities. The LADO Simulator provides a simulation of telemetry, commanding and selected subsystems functionality for the different block type satellites forming the GPS constellation. It also provides simulation of specified maneuvers and anomalies, as well as ground facilities utilized for the LADO mission. In October 2007, LADO transitioned to operations with the launch of GPS IIR-17(M). Since then, AFSPC crews have used LADO to dispose of multiple older GPS satellites, launch the remaining GPS IIR-Ms, and all of the GPS IIF satellites currently on orbit. It has also been found to be “mission capable” by AFSPC operational testers and was “operationally accepted” by HQ AFSPC/A3. LADO is also used to fly all residual GPS Block II satellites in case of sudden on orbit failure of one of the primary satellites in the constellation. LADO has successfully launched 13 GPS satellites to include five IIR-M and eight IIF vehicles. Braxton performs unit code testing, test case development, functional testing, integration testing, and provided a low risk transition approach for incorporation of IIF launch capabilities into an existing SOC. Braxton continues to provide the sustainment and maintenance of the GPS LADO system today.


GPS OCX (7 years)

Braxton delivers software and products for the GPS Ground Segment OCX Simulator (GSYS). We understand command structure, wavetrains, and the flight dynamics necessary to model the complete OCX GPS constellation simulation. We have developed the test procedures to test the simulations and systems involved. Our work on the OCX program includes all aspects of validating the simulation software and hardware from requirements development to qualification testing. Iterative risk reduction testing is a continuous, ongoing activity that proceeds concurrently with development. Below is a listing of models specifically created by Braxton in support of this effort as well as a list of enhancements made by Braxton to LADO command and control software to interface with GPS legacy and future OCX ground station equipment:

GPS Simulation Models

  • Ground Antenna Model
  • Monitor Station Chassis Model
  • RT Logic Front End Processor Model
  • ARTS Model
  • IIA SV Model
  • IIR / IIRM SV Model
  • GMIII Support to Lockheed Martin


GPS Command & Control Enhancements

  • Ground Antenna Control & Status Processing
  • Monitor Station Control & Status Processing
  • Monitor Station L-Band Message Logging
  • RT Logic Front End Processor and ARTS Control & Status Processing
  • IIA CML Ingest
  • IIA Command & Telemetry Processing
  • IIA Upload & Dump Processing
  • IIR / IIRM CML Ingest
  • IIR / IIRM Command & Telemetry Processing
  • IIR / IIRM Upload & Dump Processing
  • IIF CML Ingest
  • IIF Command & Telemetry Processing
  • IIF Upload & Dump Processing

Command and control enhancements are used to validate the GPS OCX simulator. This simulator is used for verification and validation (VV&A) of OCX operations software.

GPS III Launch Early Orbit and Checkout System

Braxton supports the Lockheed Martin Space Systems for GPS III launch contingency developing operational concepts and requirements. The Braxton team accomplished these items and is 95% code complete to launch GPS III:

  • Mission Planning
  • Space Vehicle CML ingest
  • Complete simulation connectivity through hardware
  • Full implementation of command and control with AFSCN, ICADS, OSS
  • AFSCN SGLS telemetry and commanding to include navigation payload uploads
  • Advanced electronic command planning to support GPS III unique command structure
  • All requirements and CDRLs developed in parallel with Lockheed Martin Team
  • Contingency Operations Transition, L-LCS to Block 1
  • Cyber Security, Secure Coding Implementation, and NSA Certified Guard development