It was a tedious mission. Even a greenhorn can do a direct support mission of the convoys these days. To make the situation easier, there was no sign of the existence of the most dangerous enemy for the fleet of vessels, the trade destroyer battleships belonging to the Superior Planets Alliance around the route.
"This voyage seems like a training mission for a green youth."
Lieutenant Mizoguchi yawned on the skipper seat in the narrow cockpit and scrubbed his unshaven beard. He, raised the back of the seat in the course of stretching and drew the personal terminal unit in front of his chest. Then he glanced and grasped the change of situation during his nap.
The cockpit had no useless room. Function was the primary idea to construct it. Three seats were arranged skillfully in this narrow space. Two of them, the skipper seat and the navigator seat, stood in a line considering the accelerating direction as below. The last one, the engineer seat, was in the back of them. But everyone could manipulate all the operations for cruising from each seats.
"But this room doesn't remind me that I am in a space fleet."
Mizoguchi thought absent-mindedly seeing the closed and no window equipped room. Three seats looked same direction, but it doesn't mean they face to the direction of travel. They only faced to the common information screen, and the real movement was in the direction of their overhead. There was no need to prepare to assume resist-G posture, because this fleet couldn't accelerate over 1G however hard it tried. The crews don't see the enemy even in the battle. They will notice the encounter with the enemy from the information appeared both on the common and the personal screen, and the battle should have finished while they are staring at the numerical values. When they are defeated, this cockpit would immediately change itself to space before they notice what has happened.
He shook his head and kicked out the sleepiness.
Ensign Datz, being on his duty in the navigator seats, looked the skipper and said.
"You have still more time till your watch comes."
--- Of course I know. I can see the data indication.
Mizoguchi was to say so, but wasn't. This was the first mission for him to get on board with Datz, a young ensign seemed like a boy. That meant he couldn't say a joke like he always do with his partners during the voyages.
This is the first duty for Datz since he had joined the navy. Before the fleet left the port the headquarters persistently warned Mizoguchi to take care of it and to act prudently.
Datz had been a first-year officer of a private merchant ship. But when the war broke out, immediately he took the naval officer training course and became a member of the crew of Aerospace Force. So to speak the young man was a chicken still sticking pieces of egg shell on his hip. Mizoguchi was a up-from-the bottom artisan rather than a professional soldier. He became a soldier before the outbreak of the war and he was old enough to be his father.
Mizoguchi replied to him caring about his words wouldn't sound sarcastic because he knew that this young ensign always took Mizoguchi's feelings into consideration.
"You don't have to be so concerned about the shift time. You may sleep if you feel tired. May be nothing will happen after all."
Mizoguchi operated the server equipped on the arm of the seat and made hot coffee.
This was his manner during the voyage. He never left the seat. It was because he had to be seated during the acceleration period whether he hoped it or not and during the inertia cruise, it made no difference that where he was. There is no urgent need to go to the temporary beds, only two of them were equipped in this cruiser. Mizoguchi seldom left his seat until the half of this mission, which was to spend 20 days, had passed.
Their cruiser, only had a discriminate number but a name, was uncomfortable to spend time in, but it was a home-like place for Mizoguchi. The young ensign honestly reported Mizoguchi, who put the edge of the pack of coffee in the corner of his mouth and made his face long because of the nasty tasting of it.
"The convoys' relative speed is now 84 km/sec.and it follows us 600 thousand km beyond by 0.1 G acceleration. A periodical report was send to us an hour ago. It said all was in good order now.
And... we projected a preceding scout drone at 1400 hour in Ensign Johnson's watch. Interception of radio waves and searching of infrared rays reported no sign of enemy. The drone goes 300 thousand km ahead now. It will go out of our sensors' range before long."
"You ought to have added plus or minus when you report the relative speed. To say the least, the rule commands you to do so, doesn't it?"
Datz read the data on the screen in a fluster and corrected himself. Mizoguchi smiled wryly in his mind hearing Datz's report.
"You can understand it without plus or minus only to hear the data. Do you think it is a absurd rule?"
Datz saw Mizoguchi with embarrassment. For a moment, the young ensign, who was just over twenty yeas old, showed a immature look like a boy in his eyes. Mizoguchi left the pack of coffee and said slowly.
"But every rule has meaning in itself. Once a foolish man was about to make a nearmiss because he had mistaken the plus for the minus on his voyage. And then the rule, a report must be done orally with plus or minus, was made for, especially, newcomers. If there had not been for such a case, they didn't make such a rule. One can get 10 times more figures data from a glance at a digital screen than from the oral report."
Datz seemed feeling interesting in his tale. The stiffness of his look was gone of itself. He waited the next word of Mizoguchi with the gentleness of a junior colleague who wanted a suggestion from the senior one. Mizoguchi continued his words feeling ashamed in some way.
"Datz, you can understand it naturally, when you gain more experiences. Do you have any rough image of the present distance between the convoys and our fleet?"
"Yes, sir..."
Datz replied timidly. Mizoguchi said on the spot.
"Go ahead. How far is it from us to the convoys?"
"It's 600 thousand km."
In space, it was made as a rule to use km unit in order to indicate a length, which was less than 1 AU but more than 1 km both in the army or in the private. Occasionally, one used megameter to express the length between the two, whose relative speeds were almost 0. But navigators seldom used this unit but used km to indicate the length.
Mizoguchi imaged the surrounding space areas and relative position of the convoys which was accelerating and following them and asked of Datz.
"How long does it take the convoys to pass the same position now we are passing for?"
"What?"
Datz looked in the face of Mizoguchi as if he couldn't understand what he meant, but when he realized that Mizoguchi was waiting for his answer, he was to start calculating with the key-board of the navigator deck in a hurry. But Mizoguchi interrupted him and said.
"Some twelve or thirteen minutes later. You cannot cope with the situation when the enemy attacks unless you train yourself in answering for such a question without a calculation."
Datz stooped the calculation. He seemed being bewildered.
It was natural. For Datz, who was trained as a navigator, it must be easy to answer the orbit of the convoys, the consumption of fuel or the figures of the present position and the relative speed. But the question of Mizoguchi was too difficult for him even to understand what it meant. The answer of the question was something that Mizoguchi, the captain of the only fleet which escort the convoys, had to know.
The convoys were consisted of the five middle class high speed transport ships, whose mass summed up to 10,000 t. They had to pass by the asteroids belt during the mission of transporting strategic goods from the earth-orbiting supply base to the advance base in the Behind Trojan Group.
In the early stage of the Superior Planets Upheaval, lots of transport ships were destroyed during passing this area. But after the surrender of Trojan Asteroids and the satellites of Saturn in a few months after the outbreak of the war, the subversive activities of Jovian power had been losing its briskness.
So the escort flotilla consisted of only one cruiser because they supported not a man-transporting but a goods-transporting convoys on a small scale.
The guard cruiser took up its position so-called SPA cap. It always voyaged alone from 500,000 to 2,000,000 km ahead of the convoys. In order to conceal their route, the they voyaged by random acceleration added to ordinary travel pattern, fixed acceleration, turning over at the orbital intermediate position and deceleration. During the direct support mission, its engine kept silence except for the acceleration to adjust relative speed with the convoys once in a few hours. It was because to generate with a large power output motor meant to disclose its location to any low sensible sensors and to interfere the scouting movement.
The speed of the convoys, which had been continued to accelerate by 0.1 G since they had left earthly orbit, reached 800 km/sec at the asteroids belt area, the midway distance. So there was no guard behind the convoys. It was nearly empty. Of course, there was no arms which could follow and attack the convoys which pass by at such a high speed. In this point, the worth of the SPA cap existed.
Mizoguchi stopped to drink the cooled off coffee. He already had half-drunk the content though he was complaining about the taste. But at that time he felt not so hungry that he felt like not to have a meal until the next watch would over.
It was high time to change the watch. Three crews were in this guard cruiser and be on one's watch for four hours then rested eight hours or checked the machines or repaired them.
Mizoguchi, was going to tell Datz the time to change, noticed the Ensign's uneasy look. Datz said.
"Ah... May I ask you, sir?"
"What? Next watch is my turn. You may sleep. The convoys will turn the direction during the next watch and there is no acceleration for a while."
"No. I only would like to ask you about your talk."
"What talk?"
"About the time since our cruiser has passed an area till the convoys pass it."
"What is the problem about it?"
Well, I was giving a lecture to this ensign. Mizoguchi remembered and smiled bitterly. I left it half finished because a lecture isn't in my line. When he was about to open his mouth, a low alert resounded suddenly. Mizoguchi shouted.
"Prepare for the patrol! Send a yellow signal to the convoys."
Datz rushed to the communications equipment. The transmission has finished in a moment because it had sent as little-informed signal to the flag ship by the directional antenna in order not to be intercepted.
When Mizoguchi has read necessary information by manipulating his screen, a pair of ship-shoes was stuck out. In front of Datz, who was to be kicked and ducked his head, the shoes and the feet connected with them turned over. Then a rather small officer dropped into the engineer seat. He fastened the seat-belt and the arm equipped with a keyboard by utilizing the action and asked.
"Is it SPA, skipper? Does the VIP of the Armed Merchant Cruiser appear?"
Jhonasan Johnson, who is working on armament, seemed a little bit sleepy even though his agile movement.
"No, Jon boy. It may be a High-maneuver Torpedo or an Automatic Reconnaissance drone. It shows no reaction of infrared light. The orbital speed is dead now. The reconnoiter, which we has shot out ahead, found it."
The word of 'dead' is a jargon among them to describe a state that to float by adjusting its speed with the orbital speed of asteroids belt and escape the infrared light sensor by lowing the temperature of its body. Johnson glanced over the radar screen.
"Which one? Those who disguise being dead?"
Mizoguchi easily pointed out a mark on the screen. Datz looked into in a fluster, but soon lost track of it partly because he lacked of experience. Mizoguchi noticed it and made a blink arrow on the screen to indicate. Datz asked awkwardly.
"How did you tell it from the asteroids?"
"By rich experience and hunch --- I wish I could say so, but the factis that our ability of scouting is better than the enemy's ability of disguise. The way of reflecting the infrared ray is different between the asteroids and the artificiality things. Though we had often been disguised in former time, now even a kid can see through."
Mizoguchi answered troublesomely. Johnson added.
"To tell the artificial things from asteroids can be left to the information processing facility of this cruiser, but at last it depend on skipper's intuition."
Mizoguchi smiled shyly.
"It's pity of them. However well they disguised being dead, we can see through it in these days. But they never stop camouflaging. If they accelerate and attack, it expose their location even from doubled distance. So this is the only way for them to attack us.
It's a sad story. They holds their breath in order to challenge a hopeless attack. They are like guerrillas lying hidden in the darkness with a knife in order to attack the armored tank with a machine gun, though the enemies can hear even the breath of them."
"It is a automatic attacker. There is no infrared ray reflection."
Johnson murmured.
Mizoguchi turned and stared at Johnson. He was following the image of enemy silently as if there had been nothing happened.
Johnson was from the North American Continent on earth though his appearance was Mongoloid like the other two members of this fleet. But his spirit was genuine Yankee. Though he was just before 30 years old and his experience was long, he was only an ensign because he had been a volunteer and began his career from a technical petty officer.
Johnson had made a team with Mizoguchi before this war began. He was a good technical officer at piloting, navigating and arming and was a good pair with Mizoguchi. Mizoguchi trusted him all the better for his long experiences as an technical petty officer, but he began to feel a sense of incongruity these days.
--- The Yankee never have had such a war to perish their country since the States had been founded. It may be a difficult for them to imagine the enemy's feeling.
Mizoguchi concluded in his mind.
"Shall we report to the convoys?"
Datz asked noticing a certain coolness was born between Mizoguchi and Johnson.
"No. It might be better after we destroyed that one. It may not need ten minutes."
The bright dot positioned some slanting 500,000 km forward to the guard fleet. If they didn't amend the orbit, they would pass by the artificiality in 100,000 km at the closest distance. But the effective shooting range of the fleet was only 1,000 km.
"It must be a High-maneuver Torpedo. It's too big for a reconnaissance aviation. Only one..."
Mizoguchi murmured with calling the digital data from the radar on the information monitor in front of him and keeping an eye on it.
A High-maneuver torpedo was an armament which was left on a theater where convoys might pass by. When it found the enemy, it moved forward orbit of the convoys by high acceleration, and then crashed its body to scatter a lot of splinters on the orbit.
Even if it had been a very little splinter, the convoys would be completely destroyed when they rushed into them at some hundreds km/sec. The difficult point to deal with this torpedo was that it would scatter splinters even when it had been destroyed before it rushed into the forward orbit. To prevent it from scattering, one had to destroy it before it begin accelerating, or, even if it begin to accelerating, destroy it before it get enough speed.
To dodge the pursuit of the High-maneuver torpedo by correcting the orbit perpendicularly to the movement direction was another choice but it was almost impossible. The estimated encounter time was ten minutes by the guard cruiser and only twenty and some minutes even by the convoys. Neither the guard cruiser, which had only 1.5 G accelerating ability, nor the convoys, the limit accelerating ability was 0.3 G even when it threw the cargoes away, could run away from the High-maneuver torpedo, whose maximum accelerating was over 100 G.
"You see? Can you understand why you must grasp the time how long it takes from we passed to the convoys passed through an area?"
Mizoguchi asked Datz inputting a order of armament to the keyboard. The ensign answered uneasily.
"Is it the problem of splinter circle?"
Mizoguchi smiled.
"You are half right. Well, if the torpedo explodes, the splinters would scatter by 1 km/sec. Of course, it is possible to scatter them in smaller area evenly if they adjust the exploding ability. But, remember 1 km as a standard. In that case, a concentric circle, changing its scale as a 600 km radius at 10 minutes after the explosion and 1,200 km at 20 minutes, moves with the same velocity of the Torpedo at the explosion...
Can you see any movement?"
The last question was for Johnson, who had keeping his eye on the movement of the torpedo.
He answered in a low voice.
"Nothing. The orbit axis distance broke 300,000 Km. Obviously, its target is convoys. I bet."
"Prepare for the projective missile. Decide the time to shoot. But you have only one chance. If you shoot useless missiles, pay master of the fleet headquarters must complain about it."
"I know."
Johnson mechanically knocked the order into the keyboard and say in a whisper voice 'go'. For a while, a sound, which sounded as if a heavy thing scratched the outer wall, spread in a silent cockpit and the side G was generated in the gravity-free state fleet. The projective missile, the another armament of their cruiser, departed with acceleration toward the torpedo.
The structure of a projective missile was almost as same as a high-maneuver torpedo. The difference was that a torpedo waylaid the enemy by killing its speed and orbiting, a missile approached its enemy with high speed and destroyed it. It could attack a long distance like a planet between. But it needed a lot of propulsive fuel to have the same high accelerating facility as a high-maneuver torpedo. So two missile were the limit to load on the guard cruiser.
"Not be so nervous. Its target is convoys. It won't come toward us."
Mizoguchi said to the Datz who seemed being anxious in some way.
"If it wants to attack us, it already has accelerated. But it still disguises being dead. It want to block the head of the convoys after we passed by.
The unfortunate for it was that it encounter us on a halfway position. If the distance was further, to destroy it would be much harder. For the convoys was accelerating for about ten days. It might be very easy for it to find convoys even from ten times as long distance than now because we stood up as if setting off fireworks at a dark night.
On the other hand, if it positioned directly in front of our orbit, it can crash itself immediately and destroy convoys and us at the same time. Of course, the potentiality to position rightly in front of us is nearly zero."
"What would happen on the high-maneuver torpedo in the case that it didn't encounter us?"
Datz regained his composure and asked.
"Nothing will happen. It will be waiting for a year or two until its battery exhausts out. The earth, the Asteroids, the Jupiter and the Trojan Group are moving. Possibly, this area may not be a battle theater again.
It comes to nothing... I wonder what idea the man, who produced that one, considered about and made it. Did he know the machine, he had devoted all his energy to making, would be abandoned or would crash itself into the target because it is the only way to use it and produce it?"
The existence of us is also... Mizoguchi was about to say so but stopped it.
He didn't know why, but he felt danger instinctively. It was informed from the series of the numbers which had indicated on the digitized information screen. Mizoguchi kept his eye on the series of the numbers anxiously, imaging the position of the enemy and convoys and piling up the orbit of the missile on them.