Emergency Procedures
Scientists are aware of the damage that solar storms can cause to the space station's sensitive electrical systems. They have designed the space station with several safety features. Many of these features help conserve electrical energy during solar storms. Other special devices have been designed to gather and remove static electricity- excessive amounts of electrons that build-up in the lining and on the surface of the space station.

As it orbits the Earth, the space station is basically unprotected from the ravages of solar storms. There are two primary ways the electrical systems on board the station may be affected. First, the electromagnetic energy from the sun could cause the solar arrays to work less effectively. Research has shown that PV arrays subjected to enough radiation can diminish in their capacity to generate power. On January 17th when the last storm occurred, this effect was only temporary, but the PV arrays were only able to generate power at 45% of full capacity.

The second way solar storms affect electrical systems is in the computers and wires themselves. Integrated circuits, or computer chips, in the space station are vulnerable to certain kinds of solar weather. Electromagnetic energy can penetrate the electrical circuitry of a microchip and cause the logic registers to "flip their bits". This means that the memory registers in a binary logic chip can be reversed. "Bi" means two. Binary means that this particular chip can register either "1's" or "0's." All computer languages are based upon combinations of 1's and 0's. If the ones and zeros in the computer's software codes are reversed, the computer's program can become unstable or not work at all. In the same way, if the computer software that runs the space station's power system or life support system becomes scrambled, the crew must go to manual control until new software can be uploaded.

These facts have led NASA to develop ways to "harden" or shield the electronic components from dangerous solar energy levels. They have done their very best to harden the space station against solar proton events, X-Rays and gamma rays. However, shielding is not 100% effective, and radiation can still penetrate. If the intensity and duration of a future solar storm is enough, it can damage the space station's power systems or controls. If this happens, it could result in huge problems aboard the space station. Multiple computers control computer practically every electromechanical device on the space station. If the data from one computer "talking" to other computers or controls becomes contaminated with flipped bits it could cause a malfunction in the systems. This is what happened on January 17 when the Environmental Control and Life Support Systems malfunctioned. New software has since corrected the problem.

If the space station were to experience a power emergency the astronauts first must identify the problem. Once the problem has been identified corrective measures must then be followed.

If the output of the solar arrays is diminished and the ability to generate power is reduced the conservation of remaining battery power is essential. The designers of the space station have determined that a 50% total power reduction is a critical value not to fall below. If the reserve power levels approach 50% of capacity, steps must be taken to reduce the total power draw of the space station. That is, the operational levels of individual electric power consuming systems can be reduced to conserve battery power. The astronauts can selectively control the amount of power that is delivered throughout the space station, within specified limits, to "weather the storm" until the PV arrays return to normal operation. For example, the lights could be dimmed, any device not critical could be shut down and entire modules could be evacuated eliminating the need to generate light, heating, cooling and breathable oxygen.

There are procedures governing the amount of reduction each of the systems can tolerate. The electric power to conduct experiments and anything not critical to support life and guarantee safety is the first to be reduced or completely turned off. Each of the other support systems is to be reduced in a sequence that will maintain safety and station control. The absolute minimum power requirements and operating levels have been established by the design engineers for each of the systems aboard the station.