The huge, curving exterior wall of the fifty-kilometre cylinder was slowly falling away beneath him as the scooter aimed itself directly at the bomb. Yet it was impossible to judge Rama’s size, since it was completely smooth and featureless – so featureless, indeed, that it was difficult to tell that it was spinning.
One hundred seconds into the mission; he was approaching the halfway point. The bomb was still too far away to show any details, but it was much brighter against the let-black sky. It was strange to see no stars – not even brilliant Earth or dazzling Venus; the dark filters which protected his eyes against the deadly glare made that impossible. Rodrigo guessed that he was breaking a record; probably no other man had ever engaged in extra-vehicular work so close to the sun. It was lucky for him that solar activity was low.
At two minutes ten seconds the flip-over light started flashing, thrust dropped to zero, and the scooter spun through 180 degrees. -Full thrust was back in an instant, but now he was decelerating at the same mad rate Of three metres per second squared – rather better than that, in fact, since he had lost almost half his propellent mass. The bomb was twenty-five kilometres away; he would be there in another two minutes. He had hit a top speed of fifteen hundred kilometres an hour – which, for a space-scooter, was utter insanity, and probably another record. But this was hardly a routine EVA, and he knew precisely what he was doing.
The bomb was growing; and now he could see the main antenna, holding steady on the invisible star of Mercury. Along that beam, the image of his approaching scooter had been flashing at the speed of-light for the last three minutes. There were still two to go, before it reached Mercury.
What would the Hermians do, when they saw him? There would be consternation, of course; they would realize instantly that he had made a rendezvous with the bomb several minutes before they ‘even knew he was on the way. Probably some stand-by observer would call higher authority – that would take more time. But even in the worst possible case – even if the officer on duty had authority to detonate the bomb, and pressed the button immediately – it would take another five minutes for the signal to arrive.
Though Rodrigo was not gambling on it – Cosmo-Christers never gambled – he was quite sure that there would be no such instantaneous reaction. The Hermians would hesitate to destroy a reconnaissance vehicle from Endeavour, even if they suspected its motives. They would certainly attempt some form of communication first – and that would mean more delay.
And there was an even better reason; they would not waste a gigaton bomb on. a mere scooter. Wasted it would be, if it was detonated twenty kilometres from its target. They would have to move it first. Oh, he had plenty of time… but he would still assume the very worst.
He would act as if the triggering impulse would arrive in the shortest possible time – just five minutes.
As the scooter closed in across the last few hundred metres, Rodrigo quickly matched the details he could now see with those he had studied in the photographs taken at long range. What had been only a collection of pictures became hard metal and smooth plastic – no longer abstract, but a deadly reality.
The bomb was a cylinder about ten metres long and three in diameter – by a strange coincidence, almost the same proportions as Rama itself. It was attached to the framework of the carrier vehicle by an open lattice-work of short I-beams. For some reason, probably to do with the location of the centre of mass, it was supported at right angles to the axis of the carrier, so that it conveyed an appropriately sinister hammer-head impression. It was indeed a hammer, one powerful enough to smash a world.
From each end of the bomb, a bundle of braided cables ran along the cylindrical side and disappeared through the lattice-work into the interior of the vehicle. All communication and control was here; there was no antenna of any kind on the bomb itself. Rodrigo had only to cut those two sets of cables and there would be nothing here but harmless, inert metal.
Although this was exactly what he had expected, it still seemed a little too easy. He glanced at his watch; it would be another thirty seconds before the Hermians, even if they had been watching when he rounded the edge of Rama, could know of his existence. He had an absolutely certain five minutes for uninterrupted work – and a ninety-nine per cent probability of much longer than that. –
As soon as the scooter had drifted to a complete halt, Rodrigo grappled it to the missile framework so that the two formed a rigid structure. That took only seconds; he had already chosen his tools, and was out of the pilot’s seat at once, only slightly hampered by the stiffness of his heavy-insulation suit.
The first thing he found himself inspecting was a small metal plate bearing the inscription:
DEPARTMENT OF POWER ENGINEERING
Section D,
47, Sunset Boulevard,
Vulcanopolis, 17464
For information apply to Mr Henry K. Jones
Rodrigo suspected that, in a very few minutes, Mr Jones might be rather busy.
The heavy wire-cutters made short work of the cable. As the fist strands parted, Rodrigo gave scarcely a thought to the fires of hell that were pent up only centimetres away; if his actions triggered them, he would never know.
He glanced again at his watch; this had taken less than a minute, which meant that he was on schedule. Now for the back-up cable – and then he could head for home, in full view of the furious and frustrated Hermians.,
He was just beginning to work on the second cable assembly when he felt a faint vibration in the metal he was touching. Startled, he looked back along the body of the missile.
The characteristic blue-violet glow of a plasma thruster in action was hovering round one of the attitude control jets. The bomb was preparing to move. The message from Mercury was brief, and devastating. It arrived two minutes after Rodrigo had disappeared around the edge of Rama.
COMMANDER ENDEAVOUR FROM MERCURY SPACE CONTROL,
INFERNO WEST. YOU HAVE ONE HOUR FROM RECEIPT OF
THIS MESSAGE TO LEAVE VICINITY OF RAMA. SUGGEST YOU
PROCEED MAXIMUM ACCELERATION ALONG SPIN AXIS. REQUEST ACKNOWLEDGEMENT. MESSAGE ENDS.
Norton read it with sheer disbelief, then anger. He felt a childish impulse to radio back that all his crew were inside Rama, and it would take hours to get everyone out. But that would achieve nothing – except perhaps to test the will and nerve of the Hermians.
And why, several days before perihelion, had they decided to act? He wondered if the mounting pressure of public opinion was becoming too great, and they decided to present the rest of the human race with a fait accompli. It seemed an unlikely explanation; such sensitivity would have been uncharacteristic.
There was no way in which he could recall Rodrigo, for the scooter was now in the radio shadow of Rama and would be out of contact until they were in line of sight again. That would not be until the mission was completed – or had failed.
He would have to wait it out; there was still plenty of time – a full fifty minutes. Meanwhile, he had decided on the most effective answer to Mercury.
He would ignore the message completely, and see what the Hermians did next. Rodrigo’s first sensation, when the bomb started to move, was not one of physical fear; it was something much more devastating. He believed that the universe operated according to strict laws, which not even God Himself could disobey – much less the Hermians. No message could travel faster than light; he was five minutes ahead of anything that Mercury could do.
This could only be a coincidence – fantastic, and perhaps deadly, but no more than that. By chance, a control signal must have been sent to the bomb at about the time he was leaving Endeavour; while he was travelling fifty kilometres, it had covered eighty million.
Or perhaps this was only an automatic change of attitude, to counter overheating somewhere in the vehicle. There were places where the skin temperature approached fifteen hundred degrees, and Rodrigo had been very careful to keep in the shadows as far as possible.
A second thruster started to fire, checking the spin given by the first. No, this was not a mere thermal adjust-ment. The bomb was reorientating itself, to point to-. wards …….
Useless to wonder why this was happening at this precise moment in time. There was one thing in his favour; the missile was a low acceleration device. A tenth of a gee was the most that it could manage. He could hang on.