Chief Zanak's plan was simple. He would pilot a cargo shuttle in reverse out the rear end of the railroad line and deflect bomb, or destroy with plasma from the shuttle's exhaust. But this proposition was dangerous. The railroad could accelerate a shuttle to maximum of 3.6 kilometers per second. With this initial velocity it can reach a height more than 1300 kilometers at the aphelion. But it must be launched in the same direction as the rotation of the planet.
If it was launched in the direction opposite to the rotation the shuttle could not achieve orbit. The shuttle would crash into the ground or burned out in the atmosphere in no more than six minutes. If there were some mountains, the duration would be shorter. Furthermore, if it blasts its fuel at the bomb, it will even less.
"It's too dangerous..."
Ensign Yagisawa groaned. The commander looked at Zanak for a while and said,
"All right. Go. But only stand-by at this time. Maybe I'll reconsider."
Zanak saluted the commander. He didn't look like a person about to perform a dangerous mission. He looked as if he was a child given a new toy. He smiled to Yagisawa who was staring with astonishment and ran off at full speed. The commander took the intercom and said,
"Operations section? Fuel Zanak's shuttle. How much can you load by the time he arrives?... O.K. I think that's enough but don't disconnect the line till he arrives."
After that the commander talked to an officer who was still at his console.
"Transfer him into the main line at the next entrance. He won't be in time if you send him on the conducting line. Get him to the eastern edge of the railroad within one minute."
The officer cried out.
"The shuttle will rupture! It is not designed to take this much reverse acceleration. And the pilot will pass out from anemia. He will last less than three minutes."
"He will be the last man to become anemic... Well, do it."
Zanak's voice sounded from the radio in the console.
"I have arrived. Please wait another thirty seconds. I want to get a little more fuel. I will make it up with taxiing. Even though I am strapped in upside-down, I can stand 1.5 G."
"O.K.. You can do as you like."
Watching the display, the commander told another control officer.
"Check the inventory of all unmanned containers and tanks. Do we have some tankers equipped with engines left in this base ?"
"Here is one serviceable one."
"Get some empty containers and tanks into the main line behind Zanak's shuttle. They will be a screen for Zanak's shuttle. Ah, save the tanker equipped with an engine "
The bomb was closing to a little more than ten minutes away. Zanak called.
"I'm ready. Request permission to taxi into the main line."
"You need not to ask permission. Go quickly. And leave this circuit open."
"Certainly."
A faint sound of vibration emanated from the radio. The commander took a microphone.
"My previous command to take a refuge is canceled. Unless assigned other duties you are to remain at your post till last."
The vibration noise had suddenly vanished. Instead, only the hard breathing of Zanak was heard.
"Here's what's available to move into the main line. If you approve, we'll insert them now."
An air traffic control officer presented the commander a list on his personal display. The commander scanned the list and said,
"Which tanker is to be left behind ?"
"This one."
"Change it. Leave this one. It's moved. Move it to the main line. Do it soon with operations section. When it's moved, fill that tanker to as possible capacity and stand by."
There was less than ten minutes till impact. But no one was moving to shelter. Yagisawa stealthily spoke to an officer who looked free.
"Is this railroad designed to launch shuttles in reverse ?"
"In a way yes. It was designed to be able to accelerate in either direction. But the rotation loop is at the west edge. Nobody thought of launching a shuttle to the East, so the shuttle cannot turn around on the east edge."
Zanak's breathing sounded rather harsh over the radio. The shuttle was now approaching near the launch point. The commander contacted to Zanak.
"There is no need to answer, just listen."
Zanak was now under severe strain, but he answered in a cheerful voice.
"Hanging upside-down in this harness, I can sympathize with a smoked ham."
"Be quiet and listen to me. We're launching containers and tankers thirty seconds before your launch. If we are extremely lucky ,we can shoot it down with them. I don't have much hope..."
"The probability of success is a little better than shooting a satellite with a slingshot."
"And don't depend on information from this base after launch. Expect that communications will be broken till you get enough height. Even if we track the bomb's course by a satellite, you won't be in condition to listen to it. So do it in yourself with radar. If it gets too dangerous, give it up and escape. The railroad may be put out of commission, but there will probably be no casualties.
"He has reached the launch point."
An air traffic control officer said. Soon Zanak said brightly,
"Thank Heaven, I nearly became genuine bacon."
There was little more than five minutes till arrival of the bomb. The commander said,
"Your trajectory will intercept in 120 seconds. There is a slight possibility that you might collide with it. But it is best we can do."
"I'll wave a red cape beside my shuttle and dodge nimbly. Well, the tanks and containers have arrived, are you abandoning all these tanks ? These are still useful..."
"Launch them at three second intervals. They shall keep their altitude with their engine once they are launched."
The air traffic control officer reached out his hand to the console. They were in separate blocks but the velocity of the unmanned tanks and containers were almost identical. In any case, the possibility of colliding with the bomb was slight. An air traffic control officer confirmed lock-ons on the display and launched them one after another. When the last tanker was on the middle of the line, Zanak's shuttle-cargo started accelerating.
"It is a variation of Pearl-Harbor with Kamikaze."
When his shuttle had left the line, the commander said in a subdued voice.