It was huge. An elongated slab of grey rock pitted from myriad tiny collisions over the millennia.
‘What’s the mass?’ I asked as Anna manoeuvred Spirit alongside it.
‘Too massive,’ she replied.
‘By how much?’ I asked.
‘A full external tank weighs one point two three million kilos,’ said Mary.
‘And a fully fuelled Rimor is an additional three thousand kilos,’ added Anna. ‘This asteroid needs to lose two hundred thousand kilos. I’m looking for fault lines which we might use to split it.’
‘You want us to get out there with a pickaxe?’ asked Bill.
‘Possibly,’ said Mary with a laugh, ‘but the Canadarm will help us if we can find a fault to open in its structure.’
‘What’s that ridge there?’ Tosh asked.
The asteroid had a section which looked as if it had joined to the main boulder in antiquity.
‘Looks like we could fracture it if we opened that fissure.’
‘Oh, yes,’ said Mary. ‘That’s a possibility. Let me estimate the mass of that section.’
Mary busied herself with calculations while the rest of us watched the cleft passing by as the strangely shaped asteroid rotated.
‘Not quite enough, but that is better than it being too much,’ said Mary.
‘Can you bring the Canadarm around, Bill?’ I asked.
The first task was to stop the rock’s rotation and this was done by tugging on a ridge along one side each time it came into view.
‘Slow job,’ he said after we broke for lunch.
‘Well better slow than damaging the arm. How much longer?’ I said.
‘Another couple of hours should do it,’ he said, removing a hot chilli meal from the microwave.
∞∞∞∞∞∞∞
Eventually, the asteroid sat motionless alongside Spirit, giving Tosh the chance to study its internal structure using ground sonar.
‘The fissure runs more than halfway through it then turns towards the end,’ he said. ‘At some time in the past, this asteroid received a serious blow from this block and they fused together.’
‘Ideas for opening it?’ I asked.
‘The jack,’ said Bill as the Canadarm returned into view with what looked like the sort of jack you might use to lift one end of a car.
We watched, fascinated as Bill shut the jaws and eased it into the fissure. It opened, closed, and reopened several times.
‘No movement,’ said Bill, tethering the jack to a point on Spirit and walking the Canadarm back to another of the storage lockers. ‘Jackhammer this time.’
A short while later, the Canadarm reached into the fissure, pushing the hammer before it.
‘Right,’ said Bill. ‘Here we go.’
Vibrations were immediately visible along the Canadarm as compressed air was used to force the hammer into the narrow fault.
‘Amazing!’ Anna said. ‘Why can I hear it? We’re in a vacuum.’
‘Yes,’ said Tosh. ‘The vibrations run through the arm and into Spirit where it is anchored.’
The drilling continued for more than an hour.
‘Wait! Stop!’ said Tosh, studying his console. ‘Definite widening of the fissure where it changes direction inside the asteroid. Try the jack again.’
Bill tethered the drill, reattached the jack to the arm and pushed it into the crevice. ‘I’m opening and shutting it rapidly, adding a little more force on each attempt.’
‘Wow! Look at that!’ I said. ‘Anna, give us some space!’
A huge chunk of the asteroid had broken away and was moving towards Spirit. Anna jumped into action, using thrusters to move us away.
‘Wait!’ shouted Bill. ‘Need to withdraw the arm.’
We saw the arm straighten and suddenly concertina as the jack was yanked from the remains of the fissure. ‘Okay, clear!’ he said.
Anna increased the thrust to take us to a safe distance, allowing the separate fragment of the asteroid to tumble gracefully away on some new million-year orbit.
‘Mass?’ asked Tosh.
‘Give me a minute,’ said Anna impatiently as she stopped the manoeuvring and stilled Spirit. ‘One point two five million kilos. About eighty thousand kilos too massive.’
‘Bring us back alongside the new fracture and I’ll have a look at drilling some bits off,’ said Bill.
It was a long process, but eventually, Bill had chipped off enough of the asteroid to bring the mass down to an approximation of what was needed.
‘Okay,’ said Mary. ‘That will do. Now the tricky bit – attaching it to the hull.’
‘How’s the hatch going, Tosh?’ I asked.
Tosh emerged from one of the rooms off the community space carrying an airlock hatch with a long spike attached to the centre of the outer door.
‘Almost ready,’ he said. ‘This is one of the spare hatches for the Rimor to Spirit airlocks. I’ve welded this structure to it ready to insert it into the asteroid.’
‘Will that hold it?’ asked Anna.
‘Well, from the spec Mary provided, it should hold it securely during spolding. We’ll need to take care when accelerating with conventional jets though,’ said Tosh.
‘Yes,’ said Mary. ‘Once we’re spolded, the whole structure moves as one. It could possibly break away at the destination, but by then it’ll have done its job. Tosh is right about taking care under manoeuvring jets. That will put considerable stresses on the joint.’
‘Shouldn’t be any more stress than the original Rimor and tank, surely?’ said Bill.
‘You might be right,’ said Mary, ‘but we’ll take care anyway.’
I ran my fingers down the length of the steel spike. It was about two metres long and tapering from about twenty centimetres diameter at the door end, to a five-centimetre cross shape at the end. The cross-shaped profile should give it a firmer grip inside the asteroid.
‘Are you going out to fit this with Bill?’ I asked.
‘Yes. I’d like to see it through,’ said Tosh.
‘You need to find a spot where the asteroid is well clear of the Spirit,’ said Mary. ‘If it did break free, we don’t want it sideswiping the main vessel.’
‘I’ve checked that,’ said Tosh, as usual getting agitated at the possibility that someone was implying that he’d not thought the process through. ‘There is a good location about ten metres from the forward end. You ready, Bill? I’d like to get this done.’
‘Sure thing,’ said Bill, ‘but I’ll drill the hole first.’
Bill brought the Canadarm along to the forward end of the elongated boulder. The flat area to which Mary had referred looked pretty solid. Bill picked a central spot in the chosen location and drilled four small holes around the planned hole for the spike. Even that small amount of drilling started the asteroid moving away from the drill and Anna manoeuvred Spirit back to the original position. It meant we were spinning very slowly.
‘Is that spin okay, Bill?’ Anna asked.
‘Yes, for now. Not enough to cause a problem.’
He brought the Canadarm into proximity and four small probes entered the holes he’d drilled. He then moved each of them outwards from the others so that the asteroid was gripped solidly by the arm. The central drill, twenty-two centimetres in diameter, approached the rock and began to revolve.
It was a slow process as the drill inched its way into the structure, sending a cloud of dust and grit billowing away from the hole.
An hour passed and the drill head had long since disappeared. I’d resisted asking how far in it was until now.
‘What’s the depth, Bill?’
‘One point two metres. More than halfway. About forty-five minutes should do it,’ he said.
True to his word, after one hundred and eight minutes of drilling he breathed a sigh of relief and said, ‘Done. Anna, while I’m still connected, can you stop the spin? Gently and slowly now. It is only the arm and the drill holding on to the asteroid.’
‘Okay, Bill. Tiny adjustments. Here goes,’ said Anna.
I felt virtually nothing during her minuscule thrusts which took almost an hour.
‘We’re stationary,’ she said, finally.
‘Right. Withdrawing the drill head,’ said Bill.
We all took time out to have some lunch and coffee before the most treacherous part of the project was undertaken.
The two men began the lengthy process of donning suits for yet another EVA.
∞∞∞∞∞∞∞
The women and I watched from the bridge as Tosh manhandled the spare Rimor hatch towards the hole in the asteroid. We listened to their chatter.
‘That’s it aligned, Bill,’ said Tosh.
Bill carried two cylinders of an epoxy type glue, known to remain flexible in a vacuum for a short period. Each had a long pliant tube attached. Bill fed the tubes into the hole until a red mark appeared on each of them.
‘Two metres in,’ said Bill. ‘Feed in the spike, please.’
Tosh moved the hatch closer to the asteroid and the cross-profiled spike disappeared into the hole.
‘Two metres,’ said Tosh.
The hatch was now almost flush to the rock’s surface. Bill was peering into the space between the hatch and the hole. He used a staple device, similar to that used to secure tank straps when they descended to planetary surfaces, to secure both tanks to the asteroid.
‘Can you come around here and turn on the valves please, Tosh. Need both to be fully on at the same time,’ said Bill.
We watched Tosh pull himself around to just above Bill’s location.
‘Watch out for Newton’s third law when you turn the valves,’ said Bill.
‘I’m not stupid,’ said Tosh, probably annoyed that Bill might have thought he’d forget to anchor himself before rotating something in free fall.
Soon, he had one valve in each hand. ‘Say when,’ he said.
‘Okay, go!’ said Bill.
As the valves opened, the two chemicals, under pressure, forced their way down the flexible tubing. We could see that the tubes were gradually being evicted from the hole, Bill gathering them in his hands as they were pushed out of the hole by the force of the adhesive entering. Each, in turn, a second or two apart, could be seen exiting the hole. Adhesive was squirting into the vacuum of space.
‘Off,’ shouted Bill, and we saw Tosh turning the valves as quickly as he could. ‘Avoid the adhesive.’
Tosh cut his anchor and both men floated back from the hatch. A few clumps of adhesive drifted away from the asteroid. Some larger globules were heading towards Spirit and both men pursued the solidifying material and pushed it onto a trajectory which would miss the ship completely.
‘Twenty-minute wait now for the glue to fully set,’ said Bill, turning towards the bridge and waving. ‘Ship looks good from out here.’
I was relieved that the most difficult part of the attachment was complete. Now we needed to be patient.
∞∞∞∞∞∞∞
The glue became as solid as rock and both men headed towards the tunnel into Spirit where the first Rimor had been attached.
‘You go in first,’ said Bill.
I switched the monitor to the internal view of the Rimor airlock tunnel. Tosh arrived at the Spirit end and turned to face towards Bill who followed him in.
‘Okay, Anna,’ Bill said. ‘Up to you now.’
‘Here goes,’ she said and we felt some very gentle thrusts taking place, causing us to grasp handholds.
On Anna’s monitor, we could see the Spirit gradually moving back along the asteroid. On the tunnel monitor, we watched the airlock hatch appear outside the tunnel opening.
With baby steps, Anna brought Spirit closer and closer to the rock and the airlock hatch was now centred in the space.
‘Looking good, Anna,’ said Bill. ‘Seems to be aligned, so we just need it another twenty centimetres into the tunnel, please.’
‘I’ve stopped our relative motions. Try a clasp,’ said Anna.
The other monitor showed Bill reaching towards a securing bracket which he locked over the Rimor airlock hatch.
‘Perfect,’ he said. ‘Starting on the others.’
Six clasps held the hatch securely into the airlock tunnel and an O-ring tightened around the exterior of the hatch to make an airtight seal.
‘That should be it. Pump in some air,’ said Bill.
‘Tunnel pressure rising,’ I said as I opened the valve which filled that part of the system. ‘Full pressure. Hold on while I check for leaks.’
The important gauges didn’t move so much as a millimetre.
‘Seems secure. Six green lights,’ I said.
‘Opening inner hatch,’ said Tosh.
Anna, Mary, and I moved through into the recreation space and watched the inner hatch swing open, allowing Tosh and then Bill to enter. The hatch was re-sealed and they were soon being helped out of the EVA suits. Spirit was ready to go.