The Priority Mismatch Between Space Science and Satellite Operations


Corresponding author: Paul O'Brien, The Aerospace Corporation, 15049 Conference Center Drive, CH3/330, Chantilly, VA, 20151-3824, USA. (

Key Points

  • Scientists prioritize forecasting higher than do satellite operators
  • Scientists deemphasize some phenomena vital to satellite operations
  • Understanding priorities can expand the societal return on science investment

The space science community has many motivations for setting its priorities. Space scientists and the organizations that fund their research often state a desire to provide relevant research results to benefit the broader society. Satellite operators are routinely cited as customers for the results of space science research, especially research that falls into the category of space weather. However, a significant mismatch has developed between the priorities of well-meaning space scientists and their intended audience of satellite operators. The scientific community prioritizes forecasting higher than does the satellite operator, and the scientific community places a lower priority on some phenomena and particle populations that are of vital interest to satellite operations.

The satellite operator encounters the space environment in three timeframes: forecast/situational awareness, anomaly triage, and root cause analysis. In the scientific community, prediction is the strongest test of a theory. Consequently, there is a tendency in the scientific community to emphasize forecast as the highest priority among these three regimes. However, there are very few operations, such as extravehicular activities or unique testing, that are modified in anticipation of a space environment hazard—even during extreme conditions, anomalies are rare. A high-confidence “all clear” forecast could be valuable in such rare situations. Conversely, the typical highest priority of the operator is triage: applying knowledge of the space environment to support the initial anomaly resolution within the first 24 h. Thus, after-the-fact reconstruction of the environment at the affected vehicle typically provides more value to a satellite operator than does a forecast.

A satellite contends with four primary hazards presented by the radiation and plasma environment in space: Single event effects, internal charging, surface charging, and event total dose. Single event effects (SEE) are caused by protons and heavy ions with energies of 10s of MeV/amu; internal charging is caused by highly dynamic belts of electrons with energies above about 100 keV that penetrate inside a vehicle; surface charging is caused by electrons with energies of 10s of keV that interact with spacecraft surfaces; event total dose is caused primarily by solar protons and possibly also by transient belts of trapped particles, typically protons with energies near 10 MeV.

We believe that all of these hazards are neglected in one way or another by the scientific component of the space weather community. This neglect arises in part because these hazards do not always correlate strongly with the processes that dominate the dynamics of the magnetosphere. For example, surface charging is caused by high temperature electron plasma, which carries relatively less pressure and mass than the corresponding ions that accompany it in the plasma sheet and ring current. Additionally major scientific questions about this plasma can be answered without specifying the precise timing and complex spatial structure of specific plasma transport events, whereas for satellite operations the timing and spatial structure are vitally important. Further, the satellite must contend with the environment over its entire orbit, whereas the scientific community can decompose the magnetosphere into separate regions for isolated study. Thus, a successful physical model, such as an outer radiation belt electron model, cannot fully specify the associated hazard over an entire vehicle orbit. This is especially true for vehicles in low Earth orbit because they traverse magnetic field lines connected to all regions of the magnetosphere, including the inner belt, the slot, the outer belt, the ring current, the plasma sheet, the aurora, and the polar cap.

While the scientific community necessarily has priorities that extend beyond the needs of the satellite operators, a portion of the ongoing international investment in space science is clearly intended to support those operators. We hope that this introductory exposition better enables the scientific community to expand the societal return on that investment.


  • Paul O'Brien is a research scientist in the Space Sciences Department at The Aerospace Corporation. Email:

  • Joe Mazur is an associate director of the Space Sciences Department.

  • Joe Fennell is a distinguished scientist in the Space Science Applications Laboratory at The Aerospace Corporation.