The Planeteers stopped talking as the voice horn sounded. "Get it! We are going into no-weight. Prepare to stay in no-weight indefinitely. Rotation stops in two minutes."
Rip realized why the order was given. The _Scorpius_ could not maneuver while in a gravity spin, and O"Brine wanted to be free to take action if necessary.
The voice horn came on again. "Now get it again. The ship may maneuver suddenly. Prepare for acceleration or deceleration without warning. One minute to no-weight."
Rip gave quick orders. "Get lines around the equipment and prepare to haul it. I"ll get landing boats a.s.signed, and we can load. Then prepare s.p.a.ce packs. Lay out suits and bubbles. We want to be ready to go the moment we get the word."
Lines were taken from a locker and secured to the equipment. As the Planeteers worked, the ship"s spinning slowed and stopped. They were in no-weight. Rip grabbed for a hand cord that hung from the wall and hauled himself out into the engine control room. The deputy commander was at his post, waiting tensely for orders. Rip thrust against a bulkhead with one foot and floated to his side. "I need two landing boats, sir,"
he requested. "One stays on the asteroid with us."
"Take numbers five and six. I"ll a.s.sign a pilot to bring number five back to the ship after you"ve landed."
"Thank you." Rip would have been surprised at the deputy"s quick a.s.sent if Commander O"Brine hadn"t shown him that the s.p.a.cemen were ready to do anything possible to aid the Planeteers. He went back to the supply room and told Koa which boats were to be used, instructed him to get the supplies aboard, then made his way to Commander O"Brine"s office.
O"Brine was not in. Rip searched and found him in the astroplot room, watching a "scope. Green streaks called "blips" marked the panel, each one indicating an asteroid.
"All too small," O"Brine said. "We"ve only seen two large ones, and they were too large."
"s.p.a.ce is certainly full of junk," Rip commented. "At least this corner of it is pretty full."
A junior s.p.a.ce officer overheard him. "This is nothing. We"re on the edge of the asteroid belt. Closer to the middle, there"s so much stuff a ship has to crawl through it."
Rip wandered over to the main control desk. A senior s.p.a.ce officer was seated before a simple panel on which there were only a dozen small levers, a visiphone, and a radar screen. The screen was circular, with numbers around the rim like those on an Earth clock. In the center of the screen was a tiny circle. The central circle represented the _Scorpius_.
The rest of the screen was the area dead ahead. Rip watched and saw several blips on it that indicated asteroids. They were all small. He watched, interested, as the _Scorpius_ overtook them. Once, according to the screen, the cruiser pa.s.sed under an asteroid, with a clearance of only a few hundred feet.
"You didn"t miss that one by much," Rip told the s.p.a.ce officer.
"Don"t have to miss by much," he retorted. "A few feet are as good as a mile in s.p.a.ce. Our blast might kick them around a little, and maybe there"s a little mutual ma.s.s attraction, but we don"t worry about it."
He pointed to a blip that was just swimming into view, a sharp green point against the screen. "We do have to worry about that one." He selected a lever and pulled it toward him.
Rip felt sudden weight against his feet. The green point on the screen moved downward, below center. The feeling of weight ceased. He knew what had happened, of course. Around the hull of the ship, set in evenly s.p.a.ced lines, were a series of blast holes through which steam was fired.
The steam was produced instantly by running water through the heat coils of the nuclear engine. By using groups or combinations of steam tubes, the control officer could move the ship in any direction, set it rolling, spin it end over end, or whirl it in an eccentric pattern.
"How do you decide which tubes to use?" Rip asked.
"Depends on what"s happening. If we were ducking missiles from an enemy, I"d get orders from the commander. But to duck asteroids, there"s no problem. I go over them by firing the steam tubes along the bottom of the ship. That way, you feel the acceleration on your feet. If I fired the top tubes, the ship would drop out from under those who were standing.
They"d all end up on the overhead."
Rip watched for a while longer, then wandered back to Commander O"Brine.
He was getting anxious. At first the task of capturing an asteroid and moving it back to Earth had been rather unreal, like some of the problems he had worked out while training on the s.p.a.ce platform. Now he was no longer calm about it. He had faith in the Terra base Planeteer specialists, but they couldn"t figure out everything for him. Most of the problems of getting the asteroid back to Earth would have to be solved by Lt. Richard Ingalls Peter Foster.
A junior s.p.a.ce officer suddenly called, "Sir, I have a reading at two-seventy degrees, twenty-three degrees eight minutes high."
Commander O"Brine jumped up so fast that the action shot him to the ceiling. He kicked down again and leaned over the officer"s "scope.
Rip got there by pulling himself right across the top of the chart table.
The green point of light on the "scope was bigger than any other he had seen.
"It"s about the right size," O"Brine said. There was excitement in his voice. "Correct course. Let"s take a look at it."
All hands gripped something with which to steady themselves as the cruiser spun swiftly onto the new course. The control officer called, "I have it centered, sir. We"ll reach it in about an hour at this speed."
"Jack it up," O"Brine ordered. "Heave some neutrons into it. Double speed, then decelerate to reach it in thirty minutes."
The control officer issued orders to the engine control room. In a moment acceleration plucked at them. O"Brine motioned to Rip. "Come on, Foster.
Let"s see what a.n.a.lysis makes of this rock."
Rip followed the commander to the deck below, where the technical a.n.a.lysts were located. His heart was pounding a little faster than usual, and not from acceleration, either. He found himself wetting his lips frequently and thought, _Get hold of it, boy. You"ve got nothing to worry about but high vacuum._
He didn"t really believe it. There would be plenty to worry about. Like detonating nuclear bombs and trying to figure their blast reaction. Like figuring out the course that would take them closest to the sun without pulling them into it. Like a thousand things--all of them up to him.
The chief a.n.a.lyst greeted them. "We got the orders to change course, Commander. That gave us the location of the asteroid. We"re already working on it."
"Anything yet?"
"No, sir. We"ll have the albedo measurement in a few minutes. It"ll take longer to figure the ma.s.s."
The asteroid"s efficiency in reflecting sunlight was its albedo. The efficiency depended on the material of which it was made. The albedo of pure metallic thorium was known. If the asteroid"s albedo matched it, that would be one piece of evidence.
In the same way, the ma.s.s of thorium was known. The measurements of the asteroid were being taken. They would be compared with a chunk of thorium of the same size. If it worked out, that would be evidence enough.
Commander O"Brine motioned to chairs. "Might as well sit down while we"re waiting, Foster." He took one of the chairs and looked closely at Rip.
Suddenly he grinned. "I thought Planeteers never got nervous."
"Who"s nervous?" Rip retorted, then answered his own question truthfully.
"I am. You"re right, sir. The closer we get, the more scared I get."
"That"s a good sign," O"Brine replied. "It means you"ll be careful. Got any real doubts about the job?"
Rip thought it over and didn"t think so. "Not any real ones. I think we can do it. But I"m nervous just the same. Great Cosmos, Commander! This is my first a.s.signment, and they give me a whole world to myself and tell me to bring it home. Maybe it isn"t a very big world, but that doesn"t change things much."
O"Brine chuckled. "I never expected to get an admission like that from a Planeteer."
"And I," Rip retorted, "never expected to make one like that to a s.p.a.ceman."
The chief a.n.a.lyst returned, a sheet of computations in his hand. "Report, sir. The albedo measurement is correct. This may be it."
"How long before we get the measurements and comparisons?"
"Ten minutes, perhaps."
Rip spoke up. "Sir, there"s some data I"ll need."
"What, Lieutenant?" The a.n.a.lyst got out a notebook.
"I"ll need all possible data on the asteroid"s speed, orbit, and physical measurements. I will have to figure a new orbit and what it will take to blast the ma.s.s into it."