by Colin Kapp
‘No, permanent magnets. Nickel iron of that structure ought to be highly magnetic. If the negative gravity’s only point seven I should get all the attraction I need from a fairly small magnet pack.’
‘It’ll be a right game if you end up orbiting the black hole as well!’
If he was being strictly honest, even Van Noon would have admitted his confidence had fled as the little scudder dropped him towards Negrav’s implacable surface. The nearer they approached, the more smooth and polished the asteroid’s surface appeared, until from twenty metres up he could see the perfect reflection of the scudder mirrored in the giant metal ball.
The first problem was to secure a contact with the surface. Whilst the power manoeuvrings of the scudder could keep station over a particular point on the asteroid, the problem of trying to attach an assembled magnet package to the surface was akin to trying to throw it twenty metres vertically above his head. It was not until he had experienced the situation that he began to appreciate the reasonings behind Jacko’s pessimism. What he had failed to accept subconsciously was that any work in negative gravity was akin to working on the ceiling, and that any drilling would have to take place in a “hands down, feet out” position, which was both unnerving and extremely tiring.
Jacko’s estimate of a cubic metre of material removed in thirty-six hours began to look wildly optimistic.
After a series of hair-raising manoeuvres by the scudder, the pilot managed to bring Van Noon within striking distance of the nickel-iron “ceiling”. After a few breathless moments, the magnet package stuck and the long cable trailed outwards with Fritz swinging uncertainly on the end of it. Thereafter he had to climb up the cable to reach his destination, which was no mean feat despite the lightweight flexibility of his spacesuit. This did not accord at all with his ideas on how a conquering hero, even an unorthodox one, should reach the planetary body of his choice.
Having secured himself on the cable, he then began to probe the surface above him. A small drill bit cleanly but slowly into the metal surface, though he was afraid to exert too much pressure lest he should lever away the magnets which held him there. He dutifully collected samples of the swarf which came away, tapped the hole, and screwed in a prepared eyebolt to which he attached a second line. More secure now, he brought up a large drill and drilled a hole sufficiently large for a second eyebolt to be inserted completely recessed below the surface.
This was the first permanent foothold secured on Negrav.
‘Getting any ideas, Fritz?’ Jacko’s voice came over the headphones.
‘It strikes me that with the small size of the black hole, the chances of any particular attachment to the surface being eaten in any one orbit are negligible. If we were to suspend a stand-off platform from the surface and attach it by more than an adequate number of cables, we could give ourselves a relatively safe work stage. Furthermore, it would be more comfortable than this fly on the ceiling approach.’
‘Do you want me to organize a platform?’ asked Jacko.
‘Not yet, because the chances of cutting our way in seem quite as remote as Jim Fanning predicted. There has to be an easier method. Before I leave, I want to see what the explosive charge will do. But I don’t really have much hopes unless the stuff is a lot more friable than it seems.’
‘Right. When you get those swarf samples back we’ll have some idea of the answers anyway.’
Van Noon attached his explosive package to his first eyebolt, carefully levered free his precious magnet pack, then dropped down the cable from the second eyebolt to make the precarious rendezvous with the scudder. When it had stood off to a safe distance, he fired the explosive charge remotely.
The flash was impressive because of the highly reflective surface, but the destructive effect was negligible. A further close pass in the scudder revealed only the barest depression in the solid metal surface. A slight element of plastic flow had taken place, producing an extremely shallow crater, but there was no evidence that any material had actually been removed.
Van Noon returned thoughtfully to the ship. On the face of it his exploratory trip to the surface of Negrav had been a failure. They had learnt nothing they did not already know, and the few straws at which he had clutched had disappeared like vapour in a vacuum. The problem of building an observatory on Negrav appeared as intractable as ever. As the hours wore on, however, he developed the curious quizzical look at the corners of his eyes which signalled he was far from being beaten.
He spent hours viewing the surface of Negrav with the ship’s video facilities, imagining he could see the small black hole as it sped hungrily across the surface. The optical detection of such a small object from this distance was an impossibility, and his patient perusal of the scene began to worry Jacko Hine.
What’s the score, Fritz?’
‘One up to Negrav. Our turn to play.’
‘Are we still in the game?’
‘Very much so. Negrav’s going to have its observatory, and we’re going to build it.’
‘Crazy like a fox!’ said Jacko.
‘Am I? You remember my theme at the symposium. The ability of the unorthodox engineer is to do the job with anything he can lay his hands on. Well, Negrav’s a classic set-piece—the problem and the answer bound together in a single cosmological package.’
‘You need to be joking!’
‘Think about it. Ours is a problem of method. Cutting’s too slow, and blasting’s ineffective. But suppose I gave you a tool that’ll not only cut nickel iron without effort, but will also consume the detritus? Suppose this tool needs no external power supply, and the tool wear is so low that it even finishes up marginally larger than it started. And all for no transport costs. Couldn’t you do the job with that?’
‘Yes—but—,’ spluttered Jacko, and then realization dawned. ‘You’ve lost your mind!’
‘Our cutting tool’s right down there, Jacko. And for a bonus we get an eternally spinning workpiece to go with it. No lathe required. All we need to arrange is the traverse mechanism. With the black hole we can cut a toroidal cavity right around Negrav’s equator, and they can build a hundred observatories inside there if they like.’
‘Fritz,’ said Jacko, ‘this time you’ve surpassed even your own idiot genius. But there’s one tiny point you’ve overlooked. You can’t pick up a black hole and use it as a tool. You can’t hold it. You can’t even approach it. It’ll utterly absorb anything you can fling at it.’
‘All that’s accepted,’ said Van Noon. ‘But when you’ve a job to do and there’s no conceivable way to do it, there’s only one approach left open to you. You have to exercise some good old human ingenuity.’
The work-vessel took them back to the STA base on New Australia. This was the nearest point on the Rim where Fritz could find anything like the computer capacity he needed. He would have preferred to have gone back to Chronos, but was unwilling to waste the time whilst his enthusiasm was still at fever pitch. Once they had become convinced that Van Noon was intent on going through with the scheme, his team, too, had become infected with his eagerness, and their deliberations had considerably refined and improved Fritz’s initial ideas.
The STA technicians on New Australia listened to Van Noon’s proposals with critical alarm, and sent a message by subspace radio to Terra for confirmation that the project could proceed. In the meantime, Fritz got on with his computations.
The message which came back from Terra read :
’If van Noon wants to stick out his fool neck on a scheme like that, don’t stop him. We might get lucky!
Belling, Commanding engineering reserve.’
Van Noon could almost picture the gleam in the colonel’s eye as he penned the message. Nevertheless, he received all the help he needed from the STA staff on New Australia. With his precious calculations complete, and sufficient supplies for the job, he returned with his team to the keep-station around Negrav to begin the careful observations on which the success of the operation woul
d depend. It was fairly obvious that the rest of the ship’s crew regarded the project as insane. There were moments when Van Noon was not too sure himself. Nevertheless, the future of unorthodox engineering was riding on his back, and having declared his intention, he was unable to retract.
Above all else, timing was critical. The accurate gauging of Negrav’s rotation was aided considerably by a huge dyespot which Jacko managed to produce on the surface. This was achieved in the course of a hair-raising approach to the asteroid in a scudder which was carefully manoeuvred while the dye was sprayed from pressurized canisters. With the spot in place, the rotational speed of Negrav was determined with an accuracy previously unobtainable, and Van Noon’s calculations were complete.
By far the hardest part of the operation was to give the order to proceed. Not only were the dangers considerable, but the timing needed to be immaculate and the positional accuracies held within very small limits. Additionally, there were still a few unknowns which added not only to the hazards but also to the virtual certainty of unorthodox engineering becoming a standard joke throughout the Service if things went wrong.
Having rehearsed and re-rehearsed his team, Van Noon finally reached the critical point, and gave the fateful order. Once the first scudder had left the ship and headed towards the surface, there was no turning back. It was only when he had passed this point that he began to appreciate the immensity of the forces with which he played.
Once started, there was no leisure for further thought. Jacko Hine went down with the first scudder and attached his package as specified. The second scudder was on its way before he returned. The third and most critical package, Van Noon took down himself.
There being no natural features on the surface of Negrav, he could only judge his position from the radioed instructions from observers on the ship and the relative movement of Jacko’s dye marker. This made easy sense during the long space descent but when the orb of the asteroid began to dominate the sky he lost orientation. In sudden panic he had the scudder halted until he could recalculate his bearings. It was this hesitation that probably saved his life.
As he directed the scudder to continue the descent, a sudden warning was issued by the observers on the work vessel. ‘Look out below! You’re off course and running right into the path of the black hole.’
The pilot reacted before Fritz had time to formulate his instruction. Veering crazily away in a tight arc, the little spacecraft struggled to escape from the gravitational well of the black hole which was overtaking it from the rear. Unless they could build up to escape velocity they were liable to be dragged irrevocably down into this hole to end all holes.
For a short time it looked as though they might escape completely. Then the full power of the scudder’s tiny motors became insufficient to move them any farther against the intense gravitational attraction which now arrested and began to drag them back towards the surface. There was nothing the occupants could do except sit helpless as they were seized as if by a giant hand and thrown back on to the asteroid.
The touchdown, when it came, was unexpectedly mild. Fortunately their descent had been delayed by the scudder’s motors just long enough for the black hole to have sped on its uncaring way. The friction of the craft against the asteroid’s surface was sufficient to prevent them being drawn in the black hole’s wake. Almost immediately the gravitational spasm was over, and Negrav’s own negative gravity spun them crazily back into space.
Dazed and shaken, Van Noon checked his equipment, whilst the scudder pilot tested his craft. Miraculously there had been very little damage. The scudder, though dented, was still spaceworthy even though much of its instrumentation had failed. Van Noon’s precious package, which had been the reason for the descent, likewise appeared to have suffered no permanent harm.
His timing, however, had been completely destroyed. This was a factor beyond recovery. Because of the orbiting black hole, the packages which had already been placed on Negrav had only a limited life expectancy. If his own package was not now put in place, the existing ones would all be destroyed before any new calculations could be made.
Van Noon shrugged his shoulders and took a chance. He placed the package with its magnet pack on the nearest part of the surface, knowing that its position was far from being where he had originally intended. The results would be in the lap of the gods, but it was either this or make the long haul back to New Australia for a fresh set of supplies. Then tired and disconcerted, he ordered the scudder back to the ship.
Compared to this first trip, the rest of the journeys to Negrav seemed uneventful. No less than seven other trips followed some achieving the desired accuracy, others varying. There was no time left, however, to make any corrections. Fritz had to suffer the errors and hope against hope that some overseeing deity would bring the project through. Otherwise he shuddered to think of the final results.
Then came the final phase. One after another in controlled sequence great explosions flared upon the surface of Negrav; appearing as little more than pinpoints of light to the distant observers, yet in reality being ample charges of super-high explosive. The timing was accurate according to the original schedule, but because of misplacement of several of the charges, the net effect would be anything but optimum. There followed a long period of waiting, after which the remaining charges were fired.
As Van Noon read the final collation of results, his heart sank like a stone. He had arranged to check the orbital velocity of Negrav so that it fell into a lower orbit around the black hole. In effect this meant that for a number of rotations the black hole would actually orbit inside the surface of Negrav. Then he had planned to correct Negrav’s velocity so that the black hole would return to the surface leaving a toroidal cavity inside the asteroid’s equator. Probably due to misplacement of the charges, the scheme had gone disastrously wrong. The black hole had remained inside Negrav…
Stupefied, he read the figures, but they no longer registered in his brain. Instead he saw the asteroid of Negrav being progressively eaten from inside by a small black hole so voracious that it could consume its entire host without particularly noticing the meal. Worse, if it remained inside Negrav, the asteroid would disappear entirely. Van Noon did not much fancy being known for the rest of his career as the man who lost a whole asteroid.
In an agony of indecision, he called for the orbit of the asteroid to be monitored continuously, while he searched through the ship’s stocks hoping to find sufficient explosive to kick the asteroid’s velocity up and bring the black hole again to the outside. A trip to New Australia for fresh supplies was out of the question because of the time involved. By the time they returned, Negrav would have been swallowed whole.
He was unlucky. The explosives he had brought from New Australia had been carefully calculated for the job, and the entire stock had been used. Nor did the ship carry any stocks of its own. He briefly thought of trying to nudge the asteroid with the ship itself, but concluded that the vessel was unlikely to survive the ordeal.
Disconsolate, he sat down again to check the results of the orbital monitoring. As he did so, he began to brighten considerably. When Jacko found him, he was chuckling uncontrollably, and tears of laughter were streaming down his face.
‘You’re the first person I ever saw get a belly-laugh out of a computer printout,’ said Jacko warily. ‘We don’t have a strait-jacket, so I’d better give you a shot of tranquillizer. I’d advise you not to struggle.’
‘Knock it off, Jacko! I’ve just received proof of the theorem that the deserving don’t always get what they deserve. Alternatively, the unorthodox looks after its own.’
‘Crazy like two foxes!’
‘Look at these orbital figures, Jacko. And tell me what it was about the original problem we forgot.’
Jacko took the sheets of printout and looked through them wonderingly. Then he, too, began to smile.
‘Negrav’s speeding up. If it continues to do that, the black hole’ll come outside again o
f its own accord— and soon.’
‘Right! We forgot about conservation of momentum. As the black hole removes some of Negrav’s mass, the asteroid gets lighter but its initial momentum remains. Therefore it has to go faster, and climb into a higher orbit. It’s a self-stabilizing system because whenever the black hole removes some mass from the asteroid, Negrav itself automatically retreats from the attack.’
‘So what’re we left with? The same problem only with a slightly smaller Negrav?’
‘No. Unless my figures are wrong, the black hole’s been in there long enough to give us a concentric ball and shell effect—like a marble in a table-tennis ball. The increase in Negrav’s speed is running up an exponential curve, so that when the black hole does come out it should do so at some considerable angle. With luck it’ll only puncture the shell as it comes, not eat it away. And do you realize the implications of that, my boy?’
‘We were lucky?’ asked Jacko uncertainly.
‘Yes, but not only that. It means that Negrav will be safer from attack by the black hole than ever before. And if that cavity’s the size I think it is, they’ll be able to build a major base in there, not just an observatory. They can mine Leda at their leisure, and use Negrav as an on the spot refinery and transfer station from which they can load hyper ships direct. It’ll be the most valuable space facility on the Rim.’
As the figures had predicted, the black hole did come out of Negrav. It reappeared some thirty-two hours later and finally stabilized with an orbital separation of eleven kilometres. This new orbital distance was a measure of the amount of mass which had been removed from Negrav.
The next part of the exercise was to explore the cavity itself. This was aided by the fact that they could now anchor a structure permanently on to the surface to give them safe working conditions without fear of being eaten by the black hole. With this new facility, the work progressed rapidly. Twenty metres in, they broke into free space inside the asteroid. Van Noon was first through, followed by Jacko and an assemblage of powerful lamps. Once inside, they gazed into the vastness with amazement.