‘Of course it can,’ Pete replied, ‘it’s an unimaginably sophisticated computer which recognises our complex equipment. No wonder it can track us and out manoeuvre us.’
‘So how are we going to defeat it?’ Steve said and you could cut the silence in the command dome with a knife.
‘Attention! Attention! New message coming from the SOS dwelling!’
That got everyone’s rapt attention and they stared intently at the dome display.
--C – H – L – O – R – I – N – E ---S– T – O – P – S --- T – H – E –
- B – L – A – C – K ----
‘Chlorine!?’ they all chorused.
--C – H – E – C – K --- E – S – T – U – A – R– Y ---- R – I – V – E – R – S –
- C – A – N – A – L – S ----
‘Estuaries! Rivers! What have we missed?’ said AJ.
-- N – O --- B – L – A – C – K --- W – H – Y --- C – H – L – O – R – I – N – E
--- B – U – T --- W – H – Y ----
‘No black in the estuaries and rivers, remember Zec-C’s analysis of the coast lines!’ Steve reminded everyone.
But the last line to appear chilled them all,
-- T – H– E --- B – L – A – C – K --- I – S--- K – I – L – L – I – N – G –
- T – H – E --- B – L – U– E --- P – E– O– P– L – E ---- A– G– A– I– N----
‘Oh my God!’ Olivia and Alison said in unison.
The dome displays now showed pictures of the coast lines and estuaries.
‘There is a 100 metre wide black mass along all the coast lines except at the estuaries. No black in any of the estuaries, rivers or canals.’ Confirmed Zec-C.
‘Further, chlorine levels are at their highest in the tributaries from the mountains at several hundred parts per million, reducing to 200 parts per million in the rivers and canals and 100 parts per million at the estuaries.’
‘I’ve got it!’ triumphed Pete. ‘I know why the black can’t enter the estuaries and rivers!’
Everyone looked at Pete and they knew they had to curb their impatience because a mini lecture was on its way!
‘In the manufacture of computer microchips, strong chemicals and gases are used to etch sub point one micron channels in the silicon surface. But this process is carried out using masks, under highly-controlled conditions of temperature and pressure, to ensure that the channels are only cut where they are needed. Subsequently, tiny amounts of metal are deposited in and around the channels building a circuit. This is a simplification, but the process is constantly replicated building up millions of transistors or circuits to form a microprocessor or RAM chip.’
‘What’s this all got to do with chlorine?’ interrupted Martha.
‘Chlorine is a very reactive and corrosive gas and if used uncontrolled would damage these sub point one micron circuits. But in the molecular circuits of the black beads.....
....... it would create havoc!’ Pete sat back pleased with his delivery.
‘Yes, and we’ve got chlorine on the starship!’ shouted Steve excitedly, ‘dozens of high pressure containers of the stuff!’
‘OK,’ said AJ, ‘let’s start thinking about how we can use this new intelligence but firstly where does the chlorine on Cloud Planet come from and what happens to it when it enters the sea – surely it would still affect these black beads?’
‘The upper mountain slopes of this planet contain strata of calcium hypochlorite, calcium carbonate and sodium chloride. The constant high rainfall percolates over these layers extracting minerals. When calcium hypochlorite is mixed with water you get chlorine or bleach as we commonly know it. The chlorine enters the tributaries and rivers as gas and also enters the atmosphere. When it gets to the sea it is mopped up by the excess sodium ions, forms salt and this accounts for the excessively high saline levels of the seas of Cloud Planet.’
‘So the high salinity in the sea doesn’t affect these?’ Alison held up one of the black beads, ‘doesn’t affect what’s inside these?’
‘No.’ Pete continued, ‘Weak salt solution is very mild compared to gaseous chlorine – that’s what’s stopping these beads travelling up the estuaries.’
‘I’m surprised anything survives on this planet with all this bleach about,’ Alison continued. ‘As we normally use it to kill weeds and germs!’
‘Well the trees here certainly like it considering how big they grow but, apart from them, there are no other plants on this planet.’ Olivia contributed. ‘But how are we going to use chlorine as a weapon against the black?’
‘Pete, you said that chlorine would cause havoc with the circuits in the beads,’ Steve said thoughtfully, ‘but what would happen if we exploded some of these chlorine containers in the middle of the black mass?’
‘Chaos, absolute chaos,’ replied Pete, ‘high temperature on its own would cause huge damage but high temperature chlorine gas, chlorine ions, would, I think, cause widespread devastation over a large expanse of the sea.’
‘Steve, what are you thinking?’ asked AJ.
‘When we tried to attack the cylinders, the Black put up a barrier – and more than a barrier the second time! But if we could explode chlorine missiles in the black barrier then, would we create a sufficient opening to get some really powerful warheads through and hit the cylinders?’
‘Sounds good in theory!’ said AJ. ‘Any comments?’
‘How are we going to send any missile into the mass when we already know it can take control of the on-board computers? And what’s more fire it back at us!’ Alison replied dejectedly.
‘Can we take out the on-board computers and guide it manually?’ Olivia suggested, and was immediately blasted with derisory comments and looks.
‘Wait,’ said AJ, ‘Olivia, take your thoughts further.’
‘Well, we can’t send anything with a computer on board, but what if we could aim a mechanical missile at the black mass – with nothing on board that another computer would recognise?’
‘How would we guide it? How could we time the explosion without computers?’ Alison said.
‘Pete, what could you fix up by way of a mechanical timer?’ asked AJ. ‘Could we launch a missile with chlorine containers replacing the primary warhead and just rely on time for detonation?’
However, Pete was already scribbling away on his notepad, holding his hand up, to ward off further questions while he sketched. Then he asked Zec-C to put up diagrams of the ‘D’ warhead missile on the dome mimic.
The astronauts prepared for the inevitable lecture!
‘The two warheads of the ‘D’ missile are located in front of one another on the carrier missile. The surface charge sits just behind the penetrative one and the explosion of the former just before impact blasts the penetrative charge into the body of the target where it explodes about 1 second later. So, Zec-C, can you replace the front warhead with a cluster of, say, four chlorine containers? We have multiple collars so we should be able to mount them securely.’
They all watched as the mimic display changed.
‘Good, in profile it’s not too different to the normal warhead but we’ll worry about how it flies later. Now, Zec-C, take out all the computer guidance system, everything with a circuit in it, from the carrier missile.’
It was surprising how much space appeared in the middle of the missile body.
‘Now, Zec-C, let’s put 10 kilos of plastic explosive next to the surface charge, then a sealed 20 volt heavy duty battery, followed by a mechanical timer which I’ll design, similar in size.’
The free space inside the missile body was nearly filled.
‘I can design a timer that will be started by inertia when the missile is fired from the starship. After a period of time, which Zec-C will calculate, an electrical circuit would be made and the full current through the plastic will cause it to explode. The surface charge will detonate in sympathy. The chlorine contai
ners will be blasted into the black mass and the temperature of the explosion will ensure that they disintegrate due to the enormous pressures generated inside. From the starship, I think we can launch the missiles automatically as we’ll be some distance from the target.
‘So far so good,’ said AJ, ‘but we have no guidance system, only point and shoot. Zec-C, what would be the margin of error if we fired an unguided missile like this from the starship? How near the target would we have to be?’
‘We cannot take the starship lower than 400 kilometres above sea level and for a satisfactory angle of firing we would have to be 450 kilometres from the target. This modified missile with no guidance would enter the target sea area somewhere in a grid 5 kilometres square.’
There were groans from the astronauts, and then Olivia asked.
‘Zec-C, if we wanted to hit the target with an accuracy of a couple of hundred metres square, how close would we have to be?’
‘Two kilometres above sea level and 2 kilometres from target.’
‘Then we’ll have to fire the chlorine missiles from the lander, from ROL-2,’ Olivia persisted, ‘and I’m prepared to do it!’
‘Surely we can let Zec-2 pilot the lander automatically and fire the missiles when it’s in position?’ Alison said with concern, ‘Then there’s no human risk!’
‘We’ll be very near the target, very near the black,’ countered AJ, ‘can we risk a computer command to start the process?’
‘I don’t think we dare!’ Pete cautioned. ‘The computer command has to travel wirelessly outside the lander to release the missile and trigger the ignition of the rocket propellant. If that signal is blocked or interfered with...’
‘It would jeopardise the whole operation!’ AJ concluded.
‘So apart from getting into position, everything to do with the missile attack has to be completely mechanical?’ Steve summarised. ‘Can we release the missiles manually?’
‘Yes, there is a lever switch for each missile under the control console in the command dome of each lander,’ advised Pete, ‘and the mechanical release also pulls a pin for the firing of the rocket propellant.’
‘So, someone has to be in the lander command dome to do that!’ AJ said with finality.
‘I cannot calculate a risk percentage for this operation as there are too many unknown variables. I can only reiterate the accuracy of manual firing from that position.’
This was Zec-C’s reply to AJ’s request for a risk assessment of using the lander. They had discussed the strategy at length. Alison and Steve strongly felt that they should pilot the lander but Olivia countered by saying that for such a high risk mission they should not risk two astronauts, nor should they split a team.
‘I want to volunteer for this mission,’ Olivia said firmly, ‘and do it solo. I’m back to full fitness. Correct Martha?’
Martha nodded her approval to AJ who proposed that this was the best strategy. They voted four to two in favour of Olivia piloting the lander on her own.
Then came their biggest dilemma and it was Steve who proposed the deadliest of actions.
‘We may have only one chance to do real damage to those cylinders. Let us assume that the chlorine missiles break the black barrier. Then we must hit them with two nuclear warheads to inflict the maximum damage to the enemy!’
Silence.
Silence around the command dome of LifeSeeker-1 as the astronauts considered the crime of a nuclear strike on another planet and against a menace that had so far proved totally superior and had anticipated all their actions.
‘We can’t do that!’ Martha cried anxiously. ‘We’ve taken over a century to eliminate the nuclear threat from Earth. How can we possibly justify this action on another planet?’
‘I think Steve is right,’ countered Olivia, ‘we may have only one opportunity to stop this alien menace.’
‘But the risks are so high! The nuclear missiles have to be computer guided! What if the barrier isn’t breached sufficiently?’ Alison voiced her grave concerns. ‘We could be facing our own nuclear missiles fired back at us!’
The discussion continued, arguments for and against, but eventually it was up to AJ to bring the heated debate to a conclusion.
‘We have to be clear about what we are going to do,’ said AJ gravely. ‘We are going to launch the chlorine missiles from the lander but before that time we will have to launch the attack missiles, maybe nuclear, so that they will arrive at the presumably destroyed black barrier seconds later and then on to their target of the cylinders. We may have time to abort the attack missiles before they are near enough to be interfered with but.....
....... there is no margin for error!
And once we commit......
....... well if we fail, who knows what will happen. However, we cannot do nothing and I consider the plan is the best we have in the circumstances. So, fellow astronauts, I ask you to vote firstly on the basic plan to attack and secondly on whether it should be a nuclear strike.’
The vote was six to zero for the plan to attack the cylinders and three to three regarding the nuclear strike.
AJ paused. He now had to make the final decision and he looked grimly at each of the astronauts in turn.
‘Nuclear it is!’
The die was cast!
Chapter 63
Pete’s Box of Tricks
The decision was made and they all realised the enormousness of the task ahead.
AJ and Steve were allocated the job of fixing the chlorine containers onto the front of the missiles. AJ had insisted, and all had agreed, that they produce three chlorine missiles and test fire one in the middle of the ocean. Pete had informed them that this would allow the mechanical timer to be calibrated so that any last-minute adjustments to the operational missiles could be made.
Olivia and Alison were charged with removing each missile’s guidance system and all on-board computers, including the automatic system for releasing and igniting the propellant.
All this work was to be carried out in the starship’s mechanical bay and Zec-C was commanded to select the ‘D’ missiles from armoury and bring them to the maintenance bay in their special transport carriages.
Martha and Pete would produce the mechanical timers and pack the missile with the plastic explosive and the battery. However, the timer would not be inserted into the missile until it was slung in place below the lander and the connections would be the last job for Pete before the casing cover was put back in place. This would be the most critical and vulnerable part of the operation because they would have a live missile sitting inside the starship’s lander bay.
No-one dared to contemplate the horrific consequences if that missile accidently fired before leaving LifeSeeker-1!
AJ looked in on Pete in his workshop for a progress report. His ‘den’ was an engineer’s dream with every tool, material and state of the art fabrication technique at his disposal. The starship carried a huge inventory of spares, but when you are light years from civilisation, a boffin must have the capability to produce just about anything that might be needed.
‘We’ve fitted the first missile with the chlorine containers and cleared out all the computer stuff.’ AJ informed Pete, ‘How is progress on the mechanical timer?’
‘Come and see, I’ve made the first one.’ Pete gestured AJ to a bench where Martha was putting finishing touches to what looked like a clear plastic box with two wires protruding from it.
‘I’ve used 5 millimetre thick Perspex sheet to fabricate the structure using low molecular weight poly- methyl -methacrylate in solvent as the adhesive.’
Oh, no! Thought AJ, not another lecture!
‘The key material for the timer is mercury, the only liquid metal and a perfect conductor of electricity. Zec-C has done some initial calculations on the minimum weight of mercury and the diameter of the orifice which controls the flow of the liquid.’ Pete then went on to describe the timing device.
‘Inside the box we have, for want
of simplification, a horizontal egg timer constructed from two closed tubes of Perspex separated by a metal plate with a small orifice in the centre which will direct the mercury flow to the end of the receiving tube. The left hand side is larger in diameter and will be filled to about one third its depth with mercury. We’ve already put the required weight in this part. The right hand tube is narrower in diameter and has one electrical contact at the far end and one 5 centimetres towards the middle.
‘Now, look what happens when we stand the whole box on end. Martha will demonstrate.’
AJ watched as the mercury in the upper tube formed a reservoir above the orifice and started to flow down the narrow tube into the lower compartment. It covered the first electric contact almost immediately, but took about 1 minute to fill and touch the second contact causing a light connected to the protruding leads to come on.
The Blue People of Cloud Planet Page 30