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Case Study: The Gravity Probe B Launch Decision
November 8, 2009

Making difficult decisions with conflicting or incomplete information is the essence of program/project leadership at NASA. When teams of smart, competent people present opposing viewpoints that are grounded in honest disagreements about how to interpret data, somebody ultimately has to make the call. Organizational complexity adds another degree of difficulty to these decisions when the parties include partners in industry or academia. A savvy decision-maker has to understand the interests and biases of all the stakeholders as well as the technical issues at hand.

The Gravity Probe B launch decision is a dramatic example of decision making at the program manager level. The decision involved mitigating an interference problem with a box that had been installed on the spacecraft. A fault tree analysis suggested that the most likely source of the problem was the power supply. Removing the power supply would require breaking configuration, removing and servicing the box, and then re-integrating the spacecraft.

[image-62]Anyone who has worked with space flight hardware knows that decisions to break launch configuration are not casual affairs. Breaking configuration introduces new risks: delicate items may get damaged during handling, or processing errors may be made during re-integration. The decision point in this case came just prior to the installation of the explosive bolts that would enable the spacecraft to separate from the launch vehicle during ascent; once the bolts were in place, there would be no turning back.

Cost and schedule were key considerations: early estimates suggested that breaking configuration would cost $20 million and months of delays. The program manager received conflicting opinions from the program's industry and academic partners as well as from his civil servant team. The final decision rested with him.

Making difficult decisions with conflicting or incomplete information is the essence of program/project leadership at NASA. When teams of smart, competent people present opposing viewpoints that are grounded in honest disagreements about how to interpret data, somebody ultimately has to make the call. Organizational complexity adds another degree of difficulty to these decisions when the parties include partners in industry or academia. A savvy decision-maker has to understand the interests and biases of all the stakeholders as well as the technical issues at hand.

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Gravity Probe-B Gyroscope
A member of the Gravity Probe-B team inspects one of the gyroscopes.
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NASA
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Page Last Updated: October 10th, 2014
Page Editor: NASA Administrator