by Richard Penn
‘How are we doing on the shadow, Tommy?’ she asked, skipping all the permission-to-come-aboard stuff for the occasion.
‘We are good. I have a calculation,’ said Tommy. ‘Normally, stopping dead in orbit is impossible, but this little rock has such weak gravity we can do it. Essentially we wait until we are in the sun’s shadow, then do a de-orbit burn, slowly turning toward the planet. A short burst of main drive every few minutes, will hold us in a hover.’
‘Have you looked at landing, as an alternative?’ asked Lisa.
‘I have, and it’s a possibility, but it uses almost as much fuel and we still don’t know how safe it is to land Dancer on a rock.’
She looked at the figures, ran the sums in her mind. ‘I agree. Make it so, Mister Hansen,’ she said. She’d rather grown to like that line.
‘Aye-aye, Cap’n,’ said Tommy. ‘Will we need to replace the fuel this uses up? It comes to about a ton.’
‘Good question. And I don’t have an answer for now. Implement this, and we’ll talk when I’m in the presence of a clue.’ To answer the question, she needed a destination, which meant a strategy, and she was short of all of those.
‘All hands, report to bridge and close all radiation barriers. Solar storm expected, intensity five decimal four, onset in three zero minutes. Repeat, all hands to bridge, radiation, three zero minutes.’ They strung the hammocks up the side of the bridge, so everyone could rest, and settled down. Sou took over the helm, as Tommy had been on for almost 24 hours. Stjepan handed out dosimeters and then started breakfast.
25 Riding Out
The plan to ride out the storm worked as expected, the pogo effect of the hover burns annoying but tolerable. They lay in the nets in the middle of the room during the storm, to be as far from anything metal as possible. They checked the dosimeters as Sou fired the longer burn to return them to orbit. Nobody had picked up more than a six months of their normal background exposure. This was part of their lives, they accepted a slightly raised risk of cancer as part of their lifestyle. Lisa had happy childhood memories of being packed in the station shelters, all the families together. Her childhood crush on Chep had started then, she must have been twelve, and him already working as apprentice medic.
Memories were not going to get strategies, though. She needed a strategy.
‘OK, team,’ said Lisa. ‘I’m not having much luck thinking silently, so I’ll think aloud. We have a pretty strong indication that the dark colony is on Rock Three. If I recall the orbital dynamics briefing, we can’t go directly from here to Rock Three. Correct, Tommy?’
‘Not with our full capability intact, no,’ said Tommy. ‘We could jettison the boats and the ice machine, take a full load of fuel, and just about make it.’
‘Right,’ said Lisa. ‘But arriving there with marginal fuel and all our tools left behind is not useful. So we have to go via Rock Two, and refuel there. We can’t rule out there being some dark outpost at Two, either. How much do you think the enemy will be anticipating our movements?’
‘I’ve been looking into that,’ said Sou. ‘I wanted to see how much the orbital dynamics forces us to follow the path we’re on. We have to assume the enemy has as much knowledge of that as we do. The news is not all bad. I can see several paths we might have taken, some as good as this one. It depends how well they predicted our departure.’
‘I was amazed how fast the hold got us under way,’ said Lisa. ‘I don’t like to underestimate the enemy, but I think they are probably expecting us later than now.’
‘There’s a catch though,’ said Sou. ‘There are a number of routes we might take, but they all pass by Rock Two before reaching Three. If they want to trip us up before we get there, Rock Two is a likely place to do it.’
‘Right,’ said Lisa. ‘The best place for an ambush is the place we have to pass through. But we still have to go there, even knowing that. Pinch point. Do we have any other choices? Anyone?’
‘I don’t think we can avoid going to Two,’ said Tommy. ‘I have some ideas on how to defeat a trap, but we can work that out under way.’
‘Plot us a course for Rock Two then, Mister Hansen,’ said Lisa.
‘Already done,’ said Tommy. ‘And Sou has checked it through. Burn in seven minutes, by your order.’
‘So ordered,’ said Lisa. ‘Ready to take the watch, Ms Gabai.’ Lisa was determined to fly the ship herself, for once.
‘You have the watch, Captain,’ replied Minah.
It was a shorter burn this time, a more economical path because they had to save much of their fuel for the approach to Rock Two. No barges to send them off on this leg. In theory they could save fuel by jettisoning tanks midway, but Lisa had ruled that out. The ship needed to keep all its bits. Shorter burn meant longer coasting, and they had three weeks in free fall. Time to get through many authors, learn to cast off and cast on, and to carve up most of the organs of the body. Tommy was grumbling about having to learn to design bridges and caissons, and all kinds of things he would never need to build, meant for ridiculous gravity. Shani encouraged him to learn for the test, telling him it was good for the soul. Their relationship seemed to have calmed down. Presumably Tommy had learned to pass another kind of test. Lisa did not enquire.
Somewhere along the way, Lisa, Tommy and Sou gathered to talk about the threat at Rock Two.
‘Parameters,’ said Tommy. ‘We’re assuming this is not their base, that they normally do not live there. Some time in the last few weeks, they’ve learned or guessed that we’re coming, and sent something out to stop us. Kill us, ideally. Yes?’
‘With you so far,’ said Lisa.
‘Is this something a ship, something manned?’ Sou speculated.
‘I think it will be unmanned,’ said Lisa. ‘We’re assuming the colony has a small number of men and a larger number of slaves. You don’t send out slaves armed with high explosives, they’d just come back and blow you up instead. If the core group is small, they are unlikely to spare men for a dangerous mission like this, weaken their core base. Agreed?’
‘It makes sense…’ Sou hesitated. ‘but how much can we rely on these people doing the logical thing? These are evil psychopaths we’re looking at here. Don’t mad people do mad things?’
‘I’m sure they do. But they have survived in this isolated colony for years, and they exited the transit asteroid in a pretty clever way. I think we’re looking more at bad than mad. We shouldn’t rely on it of course. How does this assumption alter our defence, Tommy?’
‘Not a hell of a lot, really. Fighting from a vessel in high space is something that hasn’t been tried all that often, I’m glad to say. I’ve looked up all the published examples, and they aren’t much help. It’s always been asymmetric. Major colonies with nuclear power and gigawatt lasers against suicide bombers in scooters packed with HE. This kind of low versus low engagement either doesn’t happen, or happens with rockhounds and smugglers who don’t publish the results. Maybe our bosses have some ideas, but it’s too late to ask them now.’
‘So… manned versus unmanned?’ Lisa reminded him he was off topic.
‘Right. Well, if we had nuclear capability, we could -‘
‘Tommy. Can you stick to our situation, please?’
‘Sorry. Yes. The main difference is that you can more easily fool a robot than a person. It needs to be pre-programmed to recognise a range of situations, and to respond to each in a particular way. Light-speed delays and secrecy rule out their controlling it in real-time from their base.
‘Fighting a vessel in high space is fairly easy for the attacker. You know from orbital dynamics where your target is going to be. You just send some HE there, and detonate it when you are close. We have three options: dodge, decoy or counter-strike. If they’re a robot, they’re very small, and they have a whole asteroid to hide on, so counter-strike is out.
‘So, that leaves dodge and decoy, which really combine into one. Wait until they know the path we’re on, then dodge to a diff
erent orbit and send a decoy there to spring their trap.’ Tommy sat back and waited for them to take it in.
‘OK, but how can we make a decoy?’ said Sou. ‘What can we build that a robot would see as us, and how do we dodge without them seeing us do it?’
‘Ass first into the unknown,’ said Tommy. ‘Assume that the robot doesn’t know about our stealth fairing, and that it is going to use radar once it thinks its seen us. We come in back end first, rocket firing, showing the thing a great big target, then at the last minute we shear off, turning the prow towards them, releasing the decoy to take the hit.’
‘What decoy?’ said Lisa. ‘We didn’t come out with a decoy. It all makes sense up to that point but—‘
‘We make one,’ said Tommy. ‘We make a ghost ship. Out of tinfoil.’
‘Do you just like to see us hanging here with our mouths open, or are you going to explain that?’ said Lisa, going along with the fun.
Tommy brought up a drawing, which was mostly empty space, with square boxes. ‘It’s a ghost ship. The same dimensions as the Dancer, but made out of plastic pipes. Every metre or so, there’s a radar reflector, a box corner made out of the foil of the gig’s fairing. For good luck, there’s running lights on the ends, fireworks and a big electromagnet in the middle, in case the proximity fuse is using different clues. Ghost ship. To be named Shadow Dancer, of course.’
‘But that’s…’ Lisa sputtered.
‘Crazy?’ answered Tommy. ‘Maybe. They called Tesla crazy, you know. The thing is, if our enemy is a robot, what are the chances they’ve programmed it for this eventuality? Zero? Negative?’
Sou and Lisa looked at each other. Looked at the plans, then looked at each other again.
‘That’s brilliant Tommy. Subject to discussion with the whole crew, I’d say it’s a plan. Shadow Dancer, indeed!’
When they discussed the plan with the whole group, only Stjepan had an objection. ‘What if it isn’t a robot?’ he asked.
‘They should still be fooled, shouldn’t they?’ said Tommy.
‘If they have a scope and see us coming in ass first but with a stealth profile, they are going to smell a rat, aren’t they?’
Nobody could argue against that, but nobody could think of a better plan either, so Shadow Dancer gained her commission.
As the rest of the ream worked on the construction, “knitting a ship” as Minah called it, Sou and Lisa worked on a plan for deploying it. It was only after they had tried a number of scenarios that they reached a conclusion that they suspected Tommy had known all along.
‘Mister Hansen, a moment please,’ said Lisa.
‘Yers? I mean um, aye, Captain?’ Tommy realised that Lisa was not in a jokey mood.
‘The plan is to come in with a high radar profile, continuing a standard approach path until we think we’ve spotted the enemy vehicle, yes? Then when we do, we release Shadow Dancer, turn our prow to the enemy, and accelerate away from our original flight path. Is that correct?’
‘Yes, Cap’n, that is correct.’
‘Mister Hansen, you are aware, are you not, that this vessel has only one main engine? In the stern? Opposite the prow?’
‘Yes Cap’n, I am aware.’
‘So what you are saying is that we are going to determine where the enemy robot is, and accelerate towards it, is if we wanted to ram it. And hope it doesn’t notice. I’ve looked up this Tesla fellow you invited us to compare you with, and frankly he doesn’t inspire confidence. Do you have anything to say?’
‘Well, yes,’ said Tommy. ‘I sort of realised this all along, but didn’t want to… highlight it. It does give us another advantage though.’
‘Really,’ said Lisa. ‘Pray tell.’
‘Well, if there are humans in the enemy ship, they won’t anticipate this move either,’ said Tommy.
‘That’s because it’s an absolutely fucking crazy thing to do! You know, don’t you, there’s a word for a fighter who relies on the enemy thinking he’s insane. Berserker.’
‘So we’re—‘
‘Going ahead with the plan,’ said Lisa. ‘What else can we do?’
From then on, the enemy missile was always referred to as the ramrobot. Lisa and Sou had moved on to twentieth century literature.
26 Rock Two
Two days from their arrival at rock two, they had a good view of it in the telescope. Like many asteroids in same family, it was similar in size and shape to Rock One, maybe a little bigger. There was no sign of chlorophyll, nothing to suggest a settlement, and so far, nothing orbiting it, either.
‘What are our chances of seeing this thing before it comes at us?’ Lisa asked the group.
‘If it’s an unmanned missile, the payload might be just five kilos. Even with a hundred to one mass ratio, the fuel tank is about a metre across. We’d see it from thirty megs or so. Say two hours out,’ said Tommy.
‘And it sees us?’ asked Sou.
‘Twenty times further out, if it has a telescope,’ said Tommy. But if it does, it’s not a bottle rocket, it’s more conspicuous. Generally, I’d guess it will see us five times sooner than we see it.
‘But that’s appalling! That gives it a huge advantage, doesn’t it?’ said Minah.
‘Not really. That’s why we’re showing it our bottom. We want it to know where we are, right up to the moment we disappear,’ said Lisa.
Only the pilots seemed to be able to grasp the whole of the plan, perhaps because it was hard for a normal person to believe.
‘So how do we know when to cut and run?’ asked Sou.
‘It’s a trade-off,’ said Tommy. ‘Too soon, and we risk it seeing us, realising Shadow Dancer is a decoy. Too late, and we risk being caught by the fireball even if the target was the decoy.’
‘Why can’t we shoot it, once we know where it is?’ asked Shani.
‘We can, and we will, but if it’s small and quick, there’s a good chance we’ll miss it.’
‘Can’t we use the fighters?’ asked Sou.
‘Once we took the fairing off the gig, we lost any stealth on that,’ said Lisa. ‘The blob is possible, but I’m very reluctant to risk it. I think it’s going to be the key to getting those children out. We’ll deploy either, or both, only when I’m sure our survival depends on it. If there’s more than one trap waiting for us here.’ Both boats had been out working for the last few days, assembling bits of Shadow Dancer like a giant toy, anchored to the ship in a few places by struts with explosive bolts.
‘Sou and I will sit in the boats during the ramrobot encounter,’ said Lisa. ‘If we see a threat beyond that, we’ll launch and deal as we can. That means Tommy is in operational command during that phase.’ God help us, she thought, but did not say. For all her good intentions to use Minah where life or death were at stake, she just didn’t have the intuitive grasp of space that comes with being a pilot.
Four hours from projected arrival, they got their first good news. Tommy reported hearing a peep sound every sixty seconds or so, in the microwave band. The hostile vessel had a radar, and it had assumed Dancer had already seen it. They hadn’t, but they saw it now. Tommy had an orbit for it within the hour, equatorial to the asteroid, and low, giving it a wide range of strike times. Lisa moved to the gig, and sent Sou to the blob, but remained in command from her screen in the boat. They continued their deceleration, offering the ramrobot a nice fat target.
‘Come on, sucker. Come and get me,’ muttered Tommy. They had it in the scope now, and it was pretty small, which hopefully translated to dumb.
Suddenly, they saw it light up, like a little sun in the telescope image. ‘Ramrobot is deployed,’ said Tommy. ‘acceleration one thousand millimetres, estimated impact in one three minutes. Repeat, impact in one three minutes.’
‘Give it time,’ said Lisa. ‘It may zig or zag.’
They watched it for five long minutes, until ‘Flame out, flame out,’ called Tommy, ‘ramrobot is coasting on collision course with Dancer. Estimate collision in eigh
t minutes. Over.’
‘Cut main engines,’ said Lisa, who had kept command. She wanted to see if the missile was actively tracking them.
‘Acceleration. Ramrobot is accelerating to match our course,’ said Tommy.
‘In six zero seconds, implement operation Shadow Dancer. Tommy, take the watch.’
‘Ready to take the watch, Captain,’ said Tommy, his voice high with excitement.
‘You have the watch, Sir.’
‘Deploying in twenty seconds… ten… five… Shadow Dancer is away. Rotating positive pitch, nine zero degrees, one two zero… one eight zero degrees, ending rotation. Confirmed nose on to target. Main engine fire—‘
‘Emergency, emergency,’ this was Sou. ‘Second radar target opened up at zero one five high ten.’ Tommy had been too busy to spot it in the dangerous action. They had discussed what to do earlier. As long as they were more than five minutes from impact…and Tommy remembered…
‘Prepare to deploy fighters in thirty seconds,’ said Tommy. ‘I will cut the main drive and give you thirty further seconds to get clear. In twenty… ten… cutting main drive.’
Both the boats sprang clear of their clamps, and each pilot pitched up and applied their main drives as soon as they were out, moving away from Dancer. A human pilot would have been able to infer the position of the now-stealthy Dancer, but hopefully the robot was too dumb. For the second robot though, the bow of Dancer was pointed the wrong way, and it would be all too clear.
‘Robot two is now firing, repeat robot two is firing,’ this was Tommy. He was carefully positioning Dancer so she always pointed at the first robot, and it seemed to have been fooled. Dancer sailed past the robot, still turning to keep it on its prow. They all held their breath as the predicted time approached, and then. ‘Yes!’ shouted Tommy. ‘Robot one has detonated. Shadow Dancer has been destroyed.’
‘Dancer from Captain, caution. Missile two is tracking you and knows your real location. Orient towards it, your one one five high one five. Over.’