SEC and at the NASA Space Radiation Analysis Group (SRAG) console at JSC are communicating. SRAG is following the activity on its monitors in Houston as well as receiving alerts and forecasts from SEC.

What follows is a best-case scenario in which the course of events is controlled by an advanced capability for using space weather forecasts to support ISS construction. It envisages a time when accurate, reliable forecast models—which again, to emphasize the point, must still be developed and "transitioned" into operation—are in place to model the transport of coronal mass ejections from the Sun to Earth, to model the effects of shocks on interplanetary particle acceleration, and to accurately model the interaction of the disturbed solar wind with Earth's magnetic field, especially its effects on the size of the zones accessible to solar energetic particles. Given all this, the history of Flight AS13 unfolds as follows:

15 October, 1730 Houston time (HT), 2330 UT

The Space Environment Center receives data showing a class X flare at S10 W15. The GOES solar X-ray sensor measures a peak flux of 10–3W/m2, and a time-integrated energy of 0.7 J/m2 in the 1 to 8 nm X-ray band is accumulated in the first 10 minutes of the event. The solar X-ray imager (SXI)(scheduled launch date: October 2000) registers the event and shows large coronal changes and loop structures, indicating a substantial coronal mass ejection (CME) has occurred. Ground-based solar observatories report that the event includes an optical flare and large radio bursts.

SEC notifies SRAG that the alert criteria for a major X-ray flare and an integrated X-ray event flux have both been reached. SRAG notifies the flight surgeon that a major solar event has occurred.

15 October, 1735 HT, 2335 UT

SEC runs its updated PROTONS 5 Model. It produces a forecast of a large SPE with a 95 percent chance of occurrence. The first increase in 30 MeV protons is forecast to begin in 25 minutes. SEC relays this information to SRAG.

15 October, 1750 HT, 2350 UT

The X-ray event is still in progress. The X-ray-integrated flux reaches 1.5 J/m2 on the GOES satellite. A new run of PROTONS 5 forecasts a total event fluence of 107p.f.u. with energy (E) > 30 MeV. The peak flux is forecast to occur on 16 October around 0900 UT. SEC reports this information to SRAG. SRAG relays it to the flight surgeon and the flight director.

15 October, 1825 HT, 16/0025 UT

Energetic particle sensors on GOES begin to show an increase in energetic particle fluxes over the range 10 to 100 MeV.

15 October, 1840 HT, 16/0040 UT

The on-board radiation instrumentation, including the tissue equivalent proportional counter (TEPC) and the internal vehicle charged-particle directional spectrometer (IV-CPDS), which have been temporarily moved about the habitable cabin for a background radiation survey, are to be returned to their usual location. The TEPC alarm is turned on and set at a low threshold, and real-time telemetry from all radiation subsystems is activated.

15 October, 1855 HT, 16/0055 UT

The Large Angle and Spectrometric Coronagraph Experiment (LASCO) coronagraph data, combined with radio and plasma wave data from the WAVES instrument on the Wind spacecraft, are



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