FDF Data Resources

Data for Accurate Orbit Determination and Analysis

The FDF generates and maintains a catalog of “Common” space weather; solar, lunar, planetary (SLP); and environmental files utilized by Flight Projects and the Near Space Network (NSN). These files are used as inputs to orbit determination and analyses. A selection of these files is available for general use.

Note that the availability of these resources may change at any time without advance notice. As such, this website should not be considered a mission-critical asset. If needed for mission support or other similar priorities, dedicated interfaces and product delivery can be coordinated with the FDF Director.

Reliably predicting a spacecraft’s deorbit timeline is an important process.  By understanding how much time is left on-orbit, mission planners and stakeholders can maximize “return-on-investment,” obtaining as much useful scientific data and observations as possible.  This involves comparing remaining consumables (like fuel and battery life) to expected mission duration, determining how much operational time is left.  And in some high-profile cases, knowing when a satellite might reenter helps with contingency planning, which could be used to extend mission life with servicing or reboosts.

A key input to the spacecraft Lifetime Prediction process is the forecasting of solar activity.  Besides influencing a spacecraft orbit through gravitational perturbation and solar radiation pressure, the Sun also influences Earth’s atmosphere.  As solar activity increases, Earth’s atmosphere expands, and the outer edge of the atmosphere exerts more drag on spacecraft in orbit.  This additional drag reduces spacecraft altitude and remaining time before reentry.  Better predictions of solar activity results in better predictions of atmospheric activity, and by association, remaining spacecraft lifetime.

The Schatten-predicted Jacchia-Roberts files, generated and maintained by contract support of the FDF, provide predicted monthly mean smoothed estimates of future solar flux, along with weighted planetary geomagnetic index (Ap) to produce atmospheric density values.  

For a catalog of the FDF’s historic Schatten Solar Flux files, refer to the Community Coordinated Modeling Center (CCMC)-maintained repository of Schatten Predictions.