by Marti Ward
“That’s my thinking too. But it would add up to another week’s delay…” Sideris ground his teeth, only to be surprised by Simba rubbing by, calming him. “If the gate mirror is destroyed, but the probes survive we could try to program EMP-A, EMP-G and EMP-NE to combine their mirrors as a makeshift gate mirror – a triple mirror would reduce the time versus using just one EMP mirror by about 40%.”
“My current calculations suggest the neutron wave will take 2 to 2.5 days to pass. At 2 days of 0.1G burn each way they would use 75% of their initial fuel load. At 2.25 days they would use 95% – except that they do not have that much left. The fuel cost and delay will be reduced for the probe heading for PTL4 as it is taking it in the right direction, although new trajectories to PTL4 will have to be calculated and validated.”
Al paused as he so often did, to allow Sideris time to think. They would have to estimate the appropriate acceleration factor based on available fuel, temperature overload constraints, and predictions of the wave duration. Their fuel load will not significantly affect the delay, but will affect survivability.
Al checked the Captain’s facial expression and body language again, before summarizing the possible outcomes: “If three probes make it back to PTL4, a combined mirror would reduce transit time from 460 days with one mirror to 266 days with three. If only two combine, it reduces it to only 325 days. But the probability of EMP-G or EMP-NE surviving is low. There is as a last resort the option of sending MD9 using Casindra’s SECASM as the mirror, with an expected transit of 144 days – and an approximately 10% chance of destroying or severely damaging Casindra instead.”
“Yes, that is a last resort, one way or the other – literally a do or die message,” agreed Sideris quietly, “Even if EMP-G and EMP-NE make it back on station at PTL4, they will be effectively dead in space – as they’ll have used up almost all their fuel! And realistically, they are unlikely to make it, which means effectively a year and half to get an acknowledgement – or a fleet of LETOs.”
“If the EMPs make it, they will still have solar panels, batteries, chemical thrusters… EMP-A and EMP-NE each will have a message drone, and instructions to send the waiting information through the wormhole. If three make it to PTL4, I suggest configuring them to send the usual 13 weeks apart, even though no response can be expected for over a year. We should receive a couple of incoming message drones in that time and could then send them back as well with the latest updates. Otherwise, eventually they should at least send an EmProbe or a LETO.”
“That’s a plan then! Please arrange programming contingent on the duration of the shockwave, initially programming with figures based on the time to pass through the Kuiper Belt but aim for 2% fuel reserves on return to PTL4, but make sure you provide them with updated figures based on the time the shockwave takes to pass Acerba.”
“Acknowledged!”
“Initiate all agreed plans re protection from the shockwave.”
“The shockwave plan is operational: the agreed orders have been transmitted to all probes. In addition, default failsafes have been integrated so that EmProbes, and Casindra, will maintain their safety even if other conditions have not been satisfied. EMP-A will redeploy to PTL4 if at least one of the other probes makes it to PTL4, to allow combining their mirrors. Otherwise it will await orders at PTL5.”
“Good! Now… What do we do about those asteroids? We need to send through maximum information as soon as possible, whatever opportunity presents itself.”
Assuming there is still a Solar Command, or an Earth for that matter… In all of his nightmares, he hadn’t dreamt of them being wiped out by a radiation storm, here or there.
Sideris stood and started to pace the bridge, as he tried to fathom their situation, and uncover the possibilities among the overwhelming morass of impossibilities and unknowns.
For all he knew the media had finally uncovered the Paradisi conspiracy and the world governments had put a stop to it – or they’d blown each other up already. The first message drone back from Sol had been five months late, the next one over eight months late, the third… who knows?
We are two years into the mission and according to the mission protocol we should have had at least six message drones by now – all with a cache of food supplies. But we have received exactly two message drones – none with any food supplies. And we have no way of letting people know what’s happening to us – there’s no message drone at the gate to send. Though we could send through the EMP-G.
There was a good chance that Casindra would survive the shockwaves, but the chance of the Gate surviving was essentially nil. There was close to a 50:50 chance the EmProbes that could shelter in the umbra or penumbra of a planet or the sun could survive. Al had not been able to give a good survivability estimate for the two EmProbes that were relying purely on running, trusting in the extra shielding provided by the EmDrives. Best estimate was that he might have the LETO and one maybe two EmProbes, with at most four M-drones between them.
Al
24 July 2077 09:00
Al was struggling to answer the question the Captain had posed, What do we do about those asteroids?
Al not only had no answer, he had no place to start. But they had one more chance to send through a warning, and hopefully a plan – if they sent EMP-G. Yet they might need it here if they needed to push multiple asteroids at once. They couldn’t count on a response from Solar Command, let alone action.
The Captain had suggested they try to think as broadly and laterally as possible. To start with, whenever two moving bodies are going to collide there are three basic solutions, blow up one of them, push aside one of them, or some combination of the first two.
One of the bodies, New Eden, is rather big, and in any case we don’t want to destroy it or push it aside, so the Captain suggested we should concentrate on the asteroids individually, or else consider the total cost of handling them as one.
The Captain and the cats had gone off to the gym, but Al continued to cogitate! He was sure the Captain was still thinking about the problem – he often had new ideas after a meal or a sleep, and he usually seemed a lot calmer after some exercise.
The problem was made much more difficult in that there are so many potential meteors, but the Captain had suggested to concentrate on the biggest of the four that looked like they would impact on New Eden.
What did ‘biggest’ mean? Al decided that ‘heaviest’ would be the appropriate criterion, as there were two that were almost 10km long. Those that would be pulled in by NE gravity had estimated densities around 3g/cc while the Petra or Acerba type member nearest the actual Lagrangian had densities around twice that. To make things even more interesting, the irregularly shaped asteroids all had their own individual spins as well as their mutual rotation in their clusters and subclusters. The heavy nucleus of the entire PTL345 group weighed about a hundred million times as much as the SS Casindra fully laden. The weight of the biggest asteroid in the target cluster was about half that, and the combined weight of the four large members about double, or two hundred million Casindras.
Considering ‘blow one up’ didn’t sound very constructive, they would be better off applying their force to push the asteroid rather than to accelerate themselves into it in the hope of smashing it – even if they did, conservation of energy and momentum dictates there would be little difference in the effect on most of the fragments, which would continue more or less on course.
Considering ‘push all aside’ then, formalized as ‘apply a force’, there would need to be an effective leverage of twenty billion to 1. Given Casindra’s 0.1G sustained acceleration of her own 30720 tonne mass, a first estimate was that this 30000N thrust could shift it 6600km, if we could shift it all at once. That’s barely enough to miss New Eden – and how do we shift the whole cluster?
Considering ‘push one aside’ then, we could shift it 130000km – that’s about the distance to Acerba, and half the distance to Caeruleum. But there are four asteroids we need to shift – and wou
ld either of the moons be in the way for any of the four asteroids?
How do we make all of them miss the planet and its moons… with perhaps three ships of LETO specs, plus a limited number of probes and drones that all taken together might make the equivalent of half a LETO?
Chapter Twelve
NE–Acerba L2 – pre-shockwave
Sideris
26 July 2077 06:00
Captain Jerome Sideris strode onto the bridge in a fury of frustration.
He should have been basking in the praise for a task well done – with more to come as he reported on his close survey of the three channel islands that he’d dubbed The Three Mouseketeers – and named individually after Dumas’s characters. It should have been his moment of triumph as the pioneer that had validated the potential of this star system for colonization – and now he’d gone further by being the first to breathe New Eden air and eat New Eden food. Al too deserved great praise for making all this possible – doing the work of a whole army of scientists.
Instead, he was angry – angry at the circumstances that had compromised their last message drone, angry at the lack of regular communication from Solar Command, angry at having to depend on Sol message drones coming in to be able to send one out, angry at himself for not establishing greater redundancy and holding back a message drone at the Gate… or in the cavum for that matter. Since Solar Command was ignoring the communication protocol, he should have been faster to drop protocol and prioritize the needs of the mission as he saw them.
It had seemed for a moment that everything was going as it should. A message drone had arrived through the wormhole just as they emerged from radio shadow – he suspected that somebody had timed it carefully to do just that. It had provided little news, no supplies, no new orders and no major updates, although the ecology team was excited by the survey results, and the extensive collection of specimens due to his ground missions – they had encouraged him to spend some more time extending the biota survey on New Eden rather than heading to Ardesco as planned. But most importantly the drone provided the wherewithal to send back their latest analyses and reports.
Eleven weeks ago, the message probe had been dispatched through the wormhole with all the data from the scans and analyses for Acerba and New Eden, and most importantly reports on the unstable asteroid cluster he’d discovered near Paradisi-Tenebra Lagrange Point 3.
Today he’d woken to find a message from a return message probe sent through the wormhole from the Sol–Jupiter Lagrange 4 station – it must have been dispatched within around two days of receiving theirs… But why couldn’t they have provided the protocol-mandated two weeks or less return for the previous probes! The probe had acknowledged safe receipt of the Tenebra samples and the New Eden biota and pathogen reports – and included messages of congratulations from Sol Reach and all ten Founders, along with orders to plot a rendezvous with the Ardesco probe and a return journey with the samples from Ardesco and New Eden.
But no mention of the asteroids… No mention of the shockwave… And why cut the mission short and skip Ardesco?
However, there was a short note from a technician, apologizing that there had been a problem transferring the logs and messages for the last 48 hours before dispatch, and asking if he could resend them… ‘We apologize for any inconvenience!’ That was why they’d got the minimum turnaround time return…
The message had arrived hours ago, but the AI hadn’t sent a response. It had obeyed his orders to the letter: ‘I need my beauty sleep – do not disturb me before 06:00 unless it is an emergency… I need the opportunity to make sure everything is up-to-date and any last-minute messages are included – do not dispatch any message probe without notifying me and giving me a chance to do so…’ Of course, providing they could ride out the ion storm, there was no particular hurry as the incoming drone would take 6 days to slow down into orbit around PTL4.
Sideris forced himself into a state of calm, as he seated himself in the command chair and waited for the screens to curl around him.
“Al, please designate the arriving message drone as MD15 and ensure the Gate probe gives priority to uploading it with the information requested in the message received this morning, including storing all logs and messages since the discovery of the asteroids with quadruple redundancy across multiple physical media and media types. Arrange for all automated systems on the message probe to flag both an asteroid warning and an ion storm warning. Include a time-stamped warning for each significant wavefront’s type, arrival and duration. Explicitly request them to send as many EmProbes and LETO-ships as possible, noting that we will be unable to retrieve or send further message probes because of our ion storm measures and the anticipated destruction of the Gate: they should assume that neither the SV-mirror nor our EmProbes will survive, and that while we do have plans to protect ourselves and the probes as documented in the logs, we do not have a plan to protect the SV-mirror. Keep it up-to-date with logs and program to automatically return as soon as it reaches the Gate – we may be out of action due to the shockwave.”
“Acknowledged! Please be advised that the ion storm will reach PTL4 and the drone around 25 minutes before it reaches us, and is estimated to reach PTL4 in 3 hours 22 minutes, almost 6 days before proposed wormhole entry. There is nothing we can do to ensure a reasonable likelihood of survival of either the gate mirror or the drone – survival probability for both is estimated at 0, but we can still send EMP-G through the Gate.”
“Thank you for your optimism, Al… Please prioritize update of the M-drone over download of newsvids, and program it to target the Gate and initiate wormhole entry without deceleration. Include up-to-date reports on the asteroids, the shockwaves and the ion storm preparedness of the four EmProbes.”
“Message drone reprioritization and updates are being transmitted! The drone can be programmed to target the Gate without deceleration, but it is not possible to initiate the wormhole to Sol without matching velocity and reversing the vector. Shouldn’t we be sending the EmProbe not the M-drone?”
“I do mean the M-drone not the EmProbe.” Sideris was still processing how that was going to work, but Al continued with the preparedness report he was in the process of uploading.
“The EmProbe from Ardesco to PTL5 is back in eclipse and should emerge into the shelter of Paradisi in 5 hours 32 minutes – EMP-A will pass near the Ring of Fates asteroids inside Ardesco’s orbit and take additional scans. Survival probability estimated at 83% with fuel reserves of 73%.” Sideris felt that was a good option, but was skeptical of the accuracy of Al’s probability estimate.
“The EmProbe from Tenebra to New Eden is already in the shelter of New Eden and is decelerating to match New Eden orbit at New Eden – Acerba Lagrange Point 2, arriving in 10 hours 22 minutes. Survival probability estimated at 88% with fuel reserves of 78%.” Again, Sideris agreed with Al’s assessment in general terms, and was happy that the plan provided a good chance, but there were too many factors to be able to accurately assess how good.
“The EmProbe from New Eden to PTL4 and the EmProbe at PTL4 are both scheduled to commence 50 hours of 0.1G acceleration away from the shockwave followed by 60 hours reverse acceleration, approximately 500 hours coasting and 10 hours acceleration back onto their previous course and heading. Some individual optimization for more efficient rendezvous at PTL4 will be attempted by adjusting the final delta-V phase, but this will only improve fuel estimates by about 2 or 3% respectively, or time by 2 or 3 days at the expense of their remaining fuel. Optimizing for fuel, they have a 20% probability of arrival back at PTL4 in around a month, with expected fuel reserves of 2%.” This report confirmed Sideris in his suspicions that these would mostly likely be lost – with most of their samples from New Eden on board EMP-NE.
“SS Casindra survivability is estimated at 93%, with gamma rays the primary risk. Crew and animal specimen survivability is estimated at 66%. I recommend the crew wear radiation hardened pressure suits, and zoological specimens be re
turned to cryostasis for at least the minimal 3-day sleep cycle. All waves of the ion storm involve extreme risk.”
Sideris wasn’t sure whether to interpret that as meaning that one in three crew/animals would die – one out of Simba, Samba and Sideris himself? Or did it mean that the unknowns were sufficiently variable that this was a one in three chance that they would all die – based on estimates about the likelihood of unknown variables and contingencies, based on experiences in another galaxy. The effect of radiation always involved probabilities, and the composition and distribution of shockwaves too, but they compounded quickly.
“Thank you Al, although I don’t feel that you have enough information to compute meaningful odds! Nonetheless, I confirm that I do plan on wearing my environmental suit and will put the cats in cryo for three days and the kits indefinitely. I’ll leave you to handle your specimens, and maximize radiation hardness of the bridge and vetlabs. Please drift Casindra a little closer to Acerba and hold position with continual EM-thrust towards Lagrange Point 2 – aim for an average of 0.05G.”
“Acknowledged! The 25% EM-field will provide additional protection from ionized radiation, but the reactor shielding will provide only limited protection from neutron scatter. This procedure is estimated to increase crew survivability to 76% and specimen survivability to 92% - odds are calculated using normalized estimates from the sensor data and historical Earth-based estimates for the unknown variables.”
Three chances in four of him surviving; better than nine out of ten for the cats – he’d take those odds!
“OK Al, now let’s talk about coming up with a new protocol for sending the message drone back through the Gate without decelerating and turning around – the probability of losing the message drone and the gate mirror is pretty much 100% with the existing protocol, so we need a new protocol. Gus Reach’s previous message to me had information about AGG research that had led to a new level of understanding of the wormhole, and technological enhancements that allowed specifying the exit velocity arbitrarily. We can already tune the directional vector of the wormhole substantially. Please review his message and the referenced technical data. I can’t see why the dimensional folding can’t be programmed for Sol irrespective of the entry velocity and vector, even if it means being in the wormhole a bit longer. What’s the difference between programming arbitrary exit relative to the entry and programming arbitrary entry relative to the exit? If we are bending space, why not just bend it a little more?”