GP-B Post-Flight Analysis—Final Report - Gravity Probe B - Stanford ...

13.1 Experiment Control Unit (ECU)The Experiment Control Unit (ECU) preformed nominally during GP-B Operations. All tasks were completedon schedule and without error. The ECU’s success can be directly attributed to extensive software and hardwaredevelopment and testing, anomaly identification, analysis, resolution and when necessary, rework prior tolaunch. Instrumental to the ECU’s operational success was the early insertion of experienced operationspersonnel into the development process with a “test it like you fly it” mentality as developed by Gaylord Green.Finally, the development of a modular Flight Timeline prior to launch created an environment where replanningand anomaly resolution was done with carefully thought out command sequences resulting in errorfreeimplementation.The dedication, ability and willingness of the Lockheed Martin ECU software team to develop last minutesoftware updates and additions during IOC was exemplary and contributed in no small part to the GP-Bmission success.13.1.1 ECU HardwareFigure 13-1 below shows the relative location of the forward and aft ECU boxes on the spacecraft frame.Figure 13-1. Locations of Forward and Aft ECU boxes on the GP-B spacecraft13.1.2 ECU-Controlled Heaters & Temperature SensorsThe ECU controls a number of heaters and temperature sensors inside the dewar and inside the Probe.Figure 13-2 shows the locations of ECU-operated heaters.Gravity Probe B — Post Flight Analysis • Final Report March 2007 353