The Battle of Titan
Page 21
The trick is to find a way to channel all the energy of nuclear explosion in one direction. This is easier said than done. It is done with conventional explosives by a design called shaped charge. In simple terms it is basically an explosive which is covered in a tough conical metallic case with one side left open.
The length of the tapering cone is left open to air. When the explosive explodes, it finds an easy way out of the open end of the cone and funnels most of its energy out from there, before the entire metal casing has a chance to explode, thus focusing most of the energy of the explosive in one directed jet out of the end of the cone.
This is not possible with a nuclear device. There is no known metal or any other material tough enough to form a cone, which can withstand the heat and the pressure of a nuclear explosion, even for the miniscule fractions of seconds, to direct most of the energy in one direction. The moment the nuke would explode, any known material out of which a casing is made would simply evaporate into plasma spreading the entire energy uniformly in a spherical pattern.
Humans had revived basic nuclear weapons design after a period of nearly hundred years to solve this problem. They had come up with a partial solution. A single large yield thermonuclear weapon is surrounded by a hemisphere of small and simple fission bombs.
If all of the bombs could be detonated simultaneously, then a fairly large fraction of the energy of the large yield thermonuclear bomb could be focused directly ahead towards the open end of the hemisphere. The reason was simple. The small bombs in a hemispherical geometry formed a hollow bowl made of energy.
At the center of this bowl exploded the bigger yield bomb. For the first few milliseconds, the energy of the smaller bombs held up one hemisphere from which the energy of the bigger bomb could not escape, while the open end of the hemisphere was available for the bigger bomb to freely escape.
So for the first few milliseconds, all the energy of the big bomb was directed in this open direction before the bigger blast overwhelmed the smaller blasts of the hemisphere and spread out in every direction. Those first few milliseconds directed a significant proportion of the energy of the nuke in a single direction to make it far more effective when aimed at an alien ship.
The best result the US military had been able to achieve had been to concentrate 15% of the yield of a thermonuclear weapon in a cone 30° wide which was considered the kill zone for a closely placed missile.
If the missile could be detonated point blank on the skin of an alien ship, then the kill zone increased to a cone 60° wide, where they were able to focus consistently over repeated experiments 40% of the total yield.
To give some perspective, if the Chinese had this bomb design with the same 2 megaton yield in the encounter with the alien ship, then the first bomb itself would have burnt a hole through and exited from the other side of the weapon devastating it completely if not blowing it to bits outright, or so it was thought.
The key here was that it had enough power focused in a small enough area to not just make a hole in the hull, but continue pumping energy inside, which is what did the trick finally with their third bomb that blew up inside.
This design wasn’t without its problems though. It was big and bulky for starters. It was three times the width of a conventional thermonuclear bomb of the same yield and weighed twice as much. The second and bigger problem was reliability. The entire design depended on all the bombs detonating at the same time.
If any of the bombs detonated early, then it would destroy all the other bombs. In the worst case if it was one of the smaller bombs that triggered early, then all you got was the yield of one small fission bomb. In the best case if it was the big bomb, then you got the yield of a large thermonuclear bomb but spread all around like a conventional bomb. With so many more of the small bombs compared to just one big one, the probability of the worst case was higher.
The design did also have a problem with late triggering, but that was not such an issue if it was a small bomb that triggered late. I would only spoil the geometry a bit, but the efficiency would not degrade much unless many of the small bombs fail in timing.
If it was however the big bomb that triggered late, it was the same as the worst case scenario. However the probability of that was low in case of late triggering, for the same reason that there were many more small bombs to fail than one big bomb.
Ironically, the problems with the precision of timing was not a nuclear physics problem but a computer engineering problem. All the triggers were electronically timed and switched. They were made of silicon circuits and essentially were mini computers.
The precision of timing asked from these devices was such that it was at the borderline of the current capability of silicon based switches and computers. That was one of the many reasons DARPA was funding research to improve speed of computers both conventional as well as quantum computers.
The reason the design needed wider missiles was also partly due to computer limitation. The smaller bombs had been spaced out further to give the computer more leeway and tolerance in timing. The closer you packed the smaller bombs, the faster, more precise and more coordinated the computer timing has to be.
Needless to say that the Chinese, Russians, Europeans and the Indians were also testing their own designs. What those designs were no one knew in the US, although the US design had been shared with the Europeans.
It was believed that in another 5 to 10 years, with increasing incremental speed of the silicon based computers, it may become reliable enough to be put into a weapon, and perhaps even in a thinner missile.
It was in the context of these troubled times that Jorge especially enjoyed the carefree little time he could enjoy every afternoon with Mischa holding hands in this little refuge of theirs on the park bench. Today however turned out to be different. He kept getting a continuous buzz on his personal com.
He had even refused the first few call notifications and messages, but whoever was calling, had not taken the hint. It was pretty rude of his normally understanding colleagues to disturb him, especially at this time of the day.
“Sorry darling, someone is really insistent. Let me check my messages to see who is bugging me.” Jorge said and gently pushed Mischa aside to be able to open his jacket and take out his tablet. Mischa sat up with a sigh straightening her hair and after a few moments was about to curse Jorge’s entire astrophysics department. When she looked at Jorge to say something, she stopped however.
Jorge’s face was ashen. His eyes were big and wide and his mouth open. Mischa quickly looked at the tablet Jorge was holding and turned pale herself. The message was a single line that said “They have returned.”
Chapter 18
The opening move
If ever there was a patch of sky that had been watched keenly by humans in history, none could beat the patch of sky that was being watched now on the large wall screen by Jorge and his colleagues in the department. This was the patch of sky that pointed to Shaitan the home planet of the aliens.
It was not visible in this spectrum which this image displayed, but had been artificially inserted by the computer as a dot with a small arrow pointing to it, to indicate where the planet Shaitan was. There were many dedicated telescopes in space watching this sector scanning every spectrum of the electromagnetic wave. There were entire departments in government and academia which watched and monitored this patch of sky full time.
So this time it did not require an intrepid young astronomer to figure out from old photograph of the sky about the arrival of the aliens. It was noticed almost simultaneous across the world and the word spread like wild fire. There was no possibility of this being classified and hidden from the world. It had spread through the internet in matter of minutes. And this time, the stock market did crash.
Jorge had other worries than how the human society was behaving. Those were for the politicians, the president and public officials to think about. Right now he had a job to do. Technically he was not an employee of t
he University, he was a government employee. For all practical purposes though he was part of the academic staff of the university.
His project and the wages of everyone on the project was funded by the US government. The project had the objective of studying everything possible about the planet Shaitan and try to look for its moons which must be where the aliens really had to originate from. It also was tasked to look for similar planets orbiting the sun at similar distance at the border between the Kuiper belt and the Oort cloud.
The project’s first and foremost task however was to be on the lookout for approaching Shaitan space crafts and give as early a warning as possible. Right now Jorge and his team had to find out as much as possible about this approaching craft as quickly as possible. He knew that he was going to get a call from the government, most probably the presidential advisors as well, any time and he would need as much information to give them as possible.
“Ok people. We have prepared for this for a long time, so we do this by the book slow and easy, going down the check list one by one. First order of business is to determine if they just switched on their thrusters to decelerate or whether it has been on much longer and is just coming into view for us. Could we please know the current luminosity of the ship’s drive and calibrate it against the known sensitivity of our telescopes?” Jorge said out loud to his team gathered in the room.
“Already done that.” Said a cocky young researcher, just having earned his PhD and just a few months into the project. Marion Garret reminded Jorge a lot of himself at that age. Cocky but brilliant. Hardworking but sometimes could be a bit of a jerk. Hopefully Jorge had improved with time, and perhaps Mischa deserves all the credit for that. “And the answer is…?” Jorge said testily giving Marion a sharp look.
“The answer is that they definitely switched on the ion thrusters right now. The luminosity is an order of magnitude higher than our lowest sensitivity, so it is not the case that the ship is coming to view just as it crosses the threshold of our telescope sensitivity. We would have seen them even if they had switched on their drives a 100 AU further.”
“Alright the next thing on the checklist is spectrum analysis to confirm the signature of the ion drive plasma…” Jorge started but was cut off again by Marion “Done that too.”
This time Jorge was slightly irritated and positively glaring at Marion who realized that in his excitement he must have breached some social etiquette which he usually was in the habit of doing, so he didn’t wait for Jorge to ask once again and proceeded to give the answer. “The spectrograph gives a perfect match to the previous Shaitan ship’s ion plasma signature. It is the same Helium plasma with the exact same isotopic composition. We have 100% certainty on this one boss.”
“Mr. Garret, since you seem to be well familiar with the checklist, why don’t you enlighten all of us on what you know.” Jorge said in an exasperated manner. He might as well let the kid have his say and let his steam out.
Realizing that he had been addressed formally by Jorge, which is a mild rebuke in academic circles, he straightened up and spoke to the room a bit formally. “The next item on the checklist is to estimate the speed of the alien ship. The Doppler shift of the ion plasma spectrograph has been analyzed by the computer and the velocity of Shaitan ship has been calculated at 4,800 Km/s or about 1.6% the speed of light. This is much faster than the estimated top speed of the first ship, which was at 0.7% of light.
The next item was to estimate the distance of the ship. As per pre-arranged protocols, Samantha has been in touch with all our US observatory assets in space as well as the EU and Australian ones. We have shared the pictures with each other.
The widest separation we have right now in the direction of approaching ship is between the European Herschel and the Australian Deep View orbital telescopes. Both of them are orbiting the sun in the same orbit as earth.
Herschel is leading the earth in its orbit, while Deep View is trailing. They are almost at the opposite ends of earth’s orbit and are nearly perfectly poised for measuring the parallax. The telescopes were being repositioned to point in the direction of Shaitan, when Samantha last spoke to her contacts, I am not aware of what the current situation is.” Marion looked sideways towards Samantha with a look of enquiry in his face.
Samantha spoke up to the room after looking at her terminal once more to get the figures right. “The results just came in. The Deep View was pointed almost in the opposite direction and took some time to reposition. The parallax calculation estimates the distance at about 5,400 AU within an accuracy of 1%.
That translates to 31 light days. So we are seeing events which are 31 days old. They lit up their engines over a month ago.” Samantha spoke with a sense of awe. As an astrophysicist she was used to seeing events that had happened millions even billions of years ago. However it was a new experience for her and humanity in general, to work on interactive events like tracking hostile ships, that needed to be measured with light lag delays measured in months and years.
Taking a cue from Samantha, Marion continued. He had taken upon himself the role of the announcer seriously. “The next item is to estimate mass of the ship. We began by estimating the volume of the ion plasma being ejected out of the drive. Since we know the distance, we know the brightness or Luminosity of the ion plasma discharge, and we know that the ion plasma is made of Helium, we can make fairly accurate estimate of the volume.
We also know the velocity at which the ship is travelling, assuming that intends to come to a stop somewhere next to earth, we know what rate it needs to decelerate, so using all that knowledge as input, we came up with an estimate of the current mass of the ship at about 65 thousand tons.
However taking into account that it will lose mass in form of reaction mass as it decelerates. It would reach earth with a mass of 40 thousand tons. That makes it about 4 times the size of the previous Shaitan Ship.”
Marion let the figure sink in. They were looking at a monster here. It made the previous goliath of an alien ship look like a small child. But Marion hadn’t finished giving the bad news. “It gets worse. Assuming it continues its current rate of uniform deceleration, it will arrive at earth in about 5 years and four months, out of which we have already lost one month in the light reaching earth.
So that leaves us with 5 years and three months give or take a few days. This is about the same as it took the last Shaitan ship, so nothing unexpected there. What is unexpected is that, when you do the back calculation knowing their maximum speed and the rate of acceleration.
We know the distance to their home planet of Shaitan, so we calculated that they have been traveling for just 15 odd years now, and will be here in 5 more. That is a whole new capability they have demonstrated. The last Shaitan ship took 39.5 years, so we assumed that is the amount of time it takes for them to reach our world.
We had made our timetable for the next arrival accordingly including our preparations for defense. Now we find that they are capable of traveling to our world in half the time. They will reach earth in 20 years and, if you excuse the expression, catch us with our pants down.”
This was indeed not good news thought Jorge. He noted that pain in the ass Marion might be, but he had run through the entire checklist and completed the task even while he was gallivanting with Mischa on their ‘date’ in the park. He kicked himself mentally. He needed to be on the top of his game now with the return of the aliens.
The first thing he needed to do was to make an executive summary for the government and the president specifically. He expected one of the presidential advisors to be calling him any moment. Just as he thought about this, as if by telepathy his personal com unit buzzed. He looked at the caller, sighed and said.
“Yes Jack, I know you need to know. I am sending within the next few minutes all that the president needs to know immediately. I am afraid the news is not good Jack. I will be sending a detailed report after a few hours after we have verified all the data with our peers and internally
discussed the conclusions within ourselves. Yeah… bye… call me if you need any clarifications after you get the report.” Jorge hung up his com.
Thus began the preparations for the second incursion of the Shaitans into our solar system. It was funny that we humans call it ‘our’ solar system. Technically the planet Shaitan also rotates around the Sun albeit at a huge distance, and as such should be considered as part of our solar system. The Shaitans could equally argue that this is ‘their’ solar system.
Humanity had expected the return of the Shaitans and had been preparing for it ever since the first incursion. From their calculations of the travel time of the first ship, they had expected the next one to occur after 40 years that much is true, although they hoped they would get more time.
Contrary to young Marion’s averring however humanity had not been caught completely with its pants down. Less prepared than they would like to be certainly, but far better prepared than the last encounter. Unfortunately the Shaitans must have done the same.
Human’s now had bigger, sturdier and more reliable ships capable of carrying humans fairly easily to Mars and back. If pushed to the limits the latest ships could even carry a fair number of people to Saturn and back, although the furthest humans had been physically was the last two missions of NASA which carried a team of 6 people to orbit around Jupiter and its moons.
They had not even landed on any of the moons of Jupiter. Humans had plenty of experience of landing, though all of it had been on Mars or earth’s moon. The ESA-ISRO conglomerate had also developed similar capabilities. Their manned Jupiter orbit mission was underway and would reach Jupiter orbit in a few months.