Neptune...
The blue ice giant was visible on our external cameras, as an orb slowly growing in size and blocking a larger portion of our view. Soon enough, that orb would become our horizon instead of an oblate spheroid in the distance.
All ships of The Fleet State were in retrograde orientation, decelerating to a safe speed before hitting the planet's atmosphere. I was watching our trajectory change over Mei's shoulder, on her navigation screen. Meanwhile, the enemy AI-driven motherhips were paying it safe; they were not rushing to catch up with us, because they knew very well the terrors of high velocity atmospheric entries.
It was one of those times during which Sir Isaac Newton was both a friend and foe.
"Expecting penetration in one hour." Mei said. This meant that, in about one hour, the ships would disengage their main engines and re-orient themselves for atmospheric entry. Failure to do so could lead to catastrophic failures; because during atmospheric entry, due to the compression of atmospheric gases in front of the ship, a super-heated plasma would form. With the high-G deceleration caused by friction, this was an excellent combination of forces to rip the strongest ships apart.
With those in mind, I sat in front of a computer console.
"Mei, please export the ship's entry trajectory data to my console."
"Yes, sir; here you go."
Using the trajectory data Mei provided, and some information in the ship's library on Neptune's atmosphere and the ship's design, I ran some calculations. Simulating various entry speeds and angles, I was trying to find the safest way to hit the atmosphere.
"Mei, I will be sending simulation results to help you out a bit. I expect a minimum 3100 Kelvin temperature peak, and about 4.5G of deceleration."
"That sounds somewhat harsh." Mei said. "Not for our ship maybe, but for mining vessels and such."
"You might be right." I said. "They aren't exactly designed to survive atmospheric entries."
"What will we do with them?" Mei asked.
"I have an idea." I said. "Those ships should use a shallower descent, on higher layers of the atmosphere. After they slow down enough, they can dive deeper into the planet to meet with the rest of the fleet."
"I really doubt those ships can stand much external pressure. I don't think we can get them so far down into the atmosphere." Mei argued.
"Ugh." I said. "Why did you have to be right about that?"
"I have an idea." Professor Yamamari joined the conversation. "Why don't they just stay in the higher layers of atmosphere?"
"Because then, they will be easy targets for the enemy ships." I said. "We will need those mining ships later on."
The conversation abruptly ended there. All of us spent the next five minutes thinking in silence.
"I know." Mei was the first one to speak. "If we time it right, we can get those mining ships to escape without getting caught by the enemy."
"How?"
"The mining ships simply won't decelerate; instead, they will accelerate, but of course without ever getting into the atmosphere." Mei said. "By the time the enemy ships come on top of us, the mining ships will be on the other side of the planet, thus unseen by the motherships. They will just perform a gravity assist and continue on their way. We can set a rendezvous point to meet with them later, once we get rid of the enemy."
"Hmm... What do you think?" I asked the professor.
"Well, I couldn't come up with anything better." he said. "Looks like her knowledge of orbital mechanics far surpasses mine."
"Alright, it is decided then." I said. "Mei, send your instructions to the mining vessels."
"On it." she said.
The mining ships left the main fleet and started moving on their new trajectory. Only within a few minutes, they turned into small dots and rectangles on our telescopes.
Not long after the separation of The Fleet, remaining ships deactivated their main drives. Using small thruster firings, Mei re-oriented Lodos for atmospheric entry.
"Since the aerodynamic properties of our ships are different, not all ships may experience the same forces." Mei said. "The Fleet might get spread apart a bit, but we can rendezvous inside the atmosphere later."
"Okay." I said. "It's alright as long as no ships bump into each other."
Some cargo ships which had retractable heat shields were in the process of deploying them. On the other hand, most warships had active cooling systems which could help the ship's outer armor layers survive atmospheric entry.
"All ships; retract radiators, solar panels and external antennas." I ordered. "Close airlock covers."
This was an important step since any protrusions from a ship's main hull would instantly get destroyed.
"All hands, brace for atmospheric entry. Get to your seats and fasten your seatbelts."
And with that last instruction, I also fastened my seatbelt.
"Engineering, report."
"No problems down here. We are GO for entry." George reported. "Exactly." said Omar, to agree with his colleague.
"I can detect the heat buildup." I said, looking at the sensors console screen.
"We should start feeling it in a few seconds." Mei said.
And just like she said, we were slowly being pushed against the bottom of our seats. The ship's accelerometers had detected the rising G forces and automatically tightened our seatbelts.
Under these uncomfortable circumstances, Mei was continuing to manually navigate the ship into Neptune's atmosphere.
"Mei, careful." I said. "We are getting excessive loads on bottom-front parts of the armor plating."
"I can see it." she said. "Coming up on peak loads, let's try to reduce drag here a bit."
Mei rotated the ship a little nose-first into the airstream. We were now being pushed against the seatbelts instead of the seat itself. As the G forces were getting higher and higher, I was feeling as if my bones were going to break.
"We are getting 5G." said Mei. "Just hold on."
Just then, I saw a ship starting to tumble on the sensors screen.
"Oh, please, no!" I yelled.
"Did something break?" Mei asked. "Did I break something?"
"No." I said. "One of our cargo ships seem to have trouble."