Impact of instrument schedule growth on mission cost and schedule growth for recent NASA missions
This study explores instrument schedule delays and their impacts on mission development schedule and cost growth for recent NASA missions. This study examines 86 instruments across 32 NASA missions. First, the relationship between instrument schedule growth and mission development cost growth is examined. It is found that instrument development delays have a prominent role in contributing to mission development schedule and cost growth. Second, instrument developments are analyzed in order to explore specific trends related to schedule growth and to determine potential contributing factors. Instrument schedule growth is examined as a function of mass, power, instrument type, and spacecraft destination. The results are then used to establish schedule rules-of-thumb that can be used for planning purposes by project and program managers in charge of future NASA development efforts.
Explanation of change (EoC) study: Considerations and implementation challenges
This paper discusses the implementation of considerations resulting from a study investigating the cost change experienced by historical NASA science missions. The study investigated historical milestone and monthly status report documentation followed by interviews with key project personnel. The reasons for cost change were binned as being external to NASA, external to the project and internal to the project relative to the project's planning and execution. Based on the results of the binning process and the synthesis of project meetings and interviews, nine considerations were made with the objective to decrease the potential for cost change in future missions. Although no one “magic bullet” consideration was discovered, the considerations taken as a whole should help reduce cost and schedule change in future NASA missions.
SeaWinds: the QuikSCAT wind scatterometer
The QuikSCAT wind scatterometer, named SeaWinds, is a scanning, pencil-beam, microwave radar that was designed to measure global ocean surface winds from space. Originally planned for flight aboard the National Space Development Agency of Japan (NASDA) Advanced Earth Observing Satellite II (ADEOS-II) spacecraft, SeaWinds was expected to continue the series of Ku-band scatterometer data initiated by the NASA Scatterometer (NSCAT). Unfortunately, the failure of NSCAT's host spacecraft, ADEOS-I, prematurely ended NSCAT's mission and created a data gap. The QuikSCAT mission was rapidly developed to fill in the data gap between NSCAT on ADEOS-I and SeaWinds on ADEOS-II. A scatterometer nearly identical to SeaWinds was quickly assembled and launched on June 19, 1999 aboard the QuikSCAT spacecraft. In this paper, we describe the QuikSCAT mission, outline the key design features of the SeaWinds scatterometer, and mention some of the current and emerging science applications.