In low Earth orbit astronauts are protected from solar flare particles by the Earth’s magnetic field, which deflects the energetic protons and electrons flung off the sun and eventually pumps them down into the atmosphere at the north and south magnetic poles. Spectacular auroras can paint the skies for several nights in a row after a big solar flare. The geomagnetic field is bashed and buckled by the storm of incoming particles; for days it vibrates and twangs like banjo strings. Radio transmissions are garbled. Even underground telephone links can be scrambled.
On Earth itself the atmosphere absorbs any particles that power through the magnetic field, so that even the most energetic solar flare does not endanger life on the surface of the planet. On the airless moon, with its minuscule magnetic field, there is only one defense: go underground and stay underground until the storm blows over.
In interplanetary space the only defenses against a magnetic storm are those the spacecraft carry with them.
"Don’t sweat it," said Pete Connors. "We all knew we couldn’t make it all the way without running into a flare." He was trying to sound reassuring, but the expression on his long-jawed face looked quite serious, like a doctor discussing surgery with his patient.
"It’s more like the flare is running into us, isn’t it?" corrected George O’Hara, the Australian geologist.
The twelve men and women of the Mars 1 crew were crammed onto the benches that lined the walls of the spacecraft’s specially shielded radiation shelter. Everyone called it the "storm cellar." In this small compartment at the rear of the habitat module, the bulky propellant tanks attached to the spacecraft’s outer hull provided a measure of protection against the lethal radiation spawned from a solar flare.
The two Mars-bound craft used their half-depleted propellant tanks to absorb some of the high-energy particles streaming out from the sun. In addition, the crafts’ storm cellars were lined with thin filaments of superconducting wire. The first person to reach the radiation shelter — Pete Connors, as it turned out — punched the switch on the wall by the hatch to energize the shielding system.
The superconducting wire generated a strong magnetic field around the storm cellar, strong enough to deflect the lightweight electrons in the cloud of particles swarming past the spacecraft. But the heavier protons were the real danger, and the magnetic field was not nearly strong enough to deflect them.
Instead, the ship’s defenses included a set of electron guns that charged the outer skin of the spacecraft to millions of volts of positive charge. In theory, the incoming protons would be deflected from the spacecraft by its megavolt positive charge, while the craft’s magnetic field would keep electrons from reaching the skin and neutralizing the positive charge.
Small versions of the system had been tested aboard satellites flung into sun-centered orbits. Unmanned satellites.
"How long will we have to stay in here?" asked Ilona Malater. She was sitting between Tony Reed and the Greek biologist on the backup team, Dennis Xenophanes. Her long fingers clutched the edge of the bench so tightly her knuckles were white.
"Twelve hours or more," answered Ollie Zieman, the American astronaut who was Connors’s backup. "Maybe a couple of days."
"My god!"
"No sweat," Zieman replied, almost jovially. "Radiation level in here is almost normal."
The shelter already felt crowded and sweltering with the smell of suppressed fear. Jamie leaned his back against the bulkhead, wondering if the magnetic field being generated by the superconducting wires mere inches away from his flesh actually had no effect on their bodies. According to the system’s designers, the field was shaped so that the storm cellar was in the clear; the field extended outward in all directions, but the shelter itself was like a bubble in its middle.
Vosnesensky and his backup, Dmitri Ivshenko, were standing in front of the communications console built into the shelter’s forward bulkhead, by the hatch. Mikhail had clamped a communications headset over his curly hair.
"Radio communication is difficult," Vosnesensky announced loudly for everyone to hear, even though he kept his back to them. "We will use the laser system."
A magnetic storm can screw up radio waves, Jamie knew, but it shouldn’t have any effect on a laser’s beam of light. He felt a tightness in his chest, anxiety, even though they had trained for such emergencies. There’s a semi-infinite number of subatomic particles out there just dying to get in here and kill all twelve of us, he thought. Like a cloud of spirits of the dead scratching and moaning outside the door.
"Mars 2 is all right," Vosnesensky announced. "Everyone in the storm cellar with no trouble."
They’ve got the extra man, Jamie thought. Dr. Li makes it thirteen they have to squeeze into their shelter.
Pete Connors got up and went to stand between Vosnesensky and the other Russian. "All the ship’s systems are working okay?" he asked loudly.
"Yes, yes." Vosnesensky pointed to the panels of lights that showed the condition of the rest of the ship. Most of the lights were green. "The equipment was built to withstand radiation. It is only we fragile creatures of flesh and bone who need protection."
Cheerful, Jamie thought. Very cheerful.
Fourteen hours later the radiation levels outside the shelter had not gone down discernibly. Jamie had dozed for a while, slumped back on the bench that lined the compartment’s wall. Joanna and the Polish biochemist who was Ilona’s backup had found enough room on the opposite bench to curl up and sleep. There were foldout cots built into the walls above the benches, but no one had bothered to use them.
Looking around with blurry eyes, Jamie saw that all four pilots were sitting up near the hatch and the comm console. The Christmas tree of monitoring panels still showed mostly green lights, although there were more red ones than before. Tony Reed was chatting amiably with Ilona and the Aussie geologist, George O’Hara, at the other end of the compartment, where food and drink dispensers were built into the rear wall.
Jamie pulled himself to his feet, feeling stiff and dull-headed. O’Hara was redhaired, rawboned, tall enough to need to stoop slightly unless he stood exactly in the midline of the compartment. Otherwise his head brushed the curving ceiling panels. He seemed an amiable enough sort. Jamie had not detected a trace of jealousy over the fact that O’Hara was to stay aboard the ship while he would be the one to go down to the surface.
"…in Coober Pedy the miners live underground most of the year," O’Hara was saying. "Too bloody hot to live up on the surface, so they’ve built a by-damn city down in the shafts and galleries. Swimming pools and everything."
Ilona was not impressed. "How much longer must we stay in here?"
"Don’t be so anxious to go out," Tony said. "This is the best place in the entire solar system to be, right now."
"Except for Earth," said Jamie.
"Ah well," Reed admitted, "we can’t have everything now, can we?"
"Reminds me of being stuck inside a bloody airliner," O’Hara said, grinning down at Ilona. "I remember once a couple years ago at Washington National, they had us buttoned up on the rampway and made us wait five bloody hours inside the bloody airplane before we could take off. Some mechanical problem they took their sweet time fixing. We drank all the booze on board and we still hadn’t moved a fucking inch. It was like a zoo by the time we actually took off."