Chapter 160 - Sol Two Hundred and Eighty-One, Am I Still Alive? (1/2)

The five Raptor 10D engines could provide more than 400 tonnes of thrust, and after the dismantling, Orion had a mass of 330 tonnes. Based on the conservation of momentum, the rocket engine had to expel enough high-speed mass to effectively reduce Orion’s high speed.

Orion’s computer precisely controlled the engine via a flight program that Tomcat had written. However, to reduce the errors in the Raptor 10D’s thick nozzles to the level of millimeters was impossible. Their original use case was not meant for the vertical descent of the spacecraft. For instance, the rockets that allowed the Falcon 9 to descend vertically relied on sensitive sensors and specialized feedback control mechanisms.

Tomcat didn’t have any of this, so it could only use the most brutal and simplest method. It directed the rocket engines’ nozzles outward to their maximums, crazily pushing the safety redundancies to the limits. This allowed Orion to hang in midair like a tumbler.

At this moment, if someone looked up from beneath the spacecraft, they would see the rocket’s exhaust drawing a gigantic cross in midair.

This was a Tomcat Cross.

In the final twelve seconds before the atmospheric entry.

“Flight-path angle adjusted again! Angle of attack leveled!”

“Raptor-05 at 85% thrust. The trajectory of flow increase for 01, 03, 07, and 09 is going as expected,” Tang Yue reported. “Orion’s speed at 4872.23 m/s… The pressure on the engine is too great. It’s just too fast.”

“Tomcat?”

“Got it.” Tomcat’s voice was heavy. “I’m monitoring it.”

The workstation’s heat-dissipating fans began to whirl crazily as the CPU fired up all its cores to indicate that not only was Orion under stress, it was also being stressed.

The five curves on the monitor rose, indicating that the five Raptor engines were increasing their thrust. To save propellant, Orion’s nine engines were ignited at different stages.

If this was the true descent, Orion would be hanging 12 kilometers high in the sky. It would decelerate by relying on the rocket engine’s reverse thrust while stabilizing itself.

Once it left orbit and began an atmospheric entry, there was no turning back.

Tang Yue and Tomcat stared at the monitor. At this point, they could do nothing but stare. Once the atmospheric entry began, most of the control was in the hands of Orion’s computer. Mission Control couldn’t easily intervene, nor could they do so in time.

Hold it.

Hold it.

Tang Yue whispered.

35 seconds into the atmospheric entry.

The Orion stably descended.

Kunlun Station remained silent in the heavy atmosphere. Only Tang Yue’s and Tomcat’s hurried, terse voices would occasionally sound.

“Take note, the IMU’s 1 errors are accumulating. The gyroscope drift has deviated beyond our initial estimates.

“The wind-facing surface’s atmospheric density is increasing. The resistance numbers are rising.”

As the atmosphere thickened, the situation faced by Orion and the workstation became complex. Flight in a vacuum and in an atmosphere were completely different. The air didn’t provide any deceleration properties to Orion and only made the environment more thorny. For the workstation, the fluid dynamical simulations were taxing, and the CPU was slowly unable to keep up.

Tang Yue swept his gaze across every number on the monitor. The numbers and diagrams that didn’t look obvious on the surface combined together to form a complete spacecraft that flew in his mind.

The altitude indicator on the monitor kept jumping. If it were a mechanical watch, the spinning gears might even produce sparks from the friction. Instead of describing the Orion as landing, it was more like a crash. A controlled and deliberate crash.

The HP workstation was unable to precisely simulate the environment of Orion’s atmospheric entry. Orion’s massive body, spanning tens of meters long, made the force distribution and work environment extremely complex. It was truly difficult for the workstation to simulate reality. After all, it wasn’t a supercomputer that physically occupied more than a hundred square meters.

In fact, Tomcat had simplified the workstation’s workload. Certain details were temporarily replaced with fixed ideal values that would be tested individually in the future. This wasn’t safe or precise, but it was a choice made from not having any options. Otherwise, the computer might really explode in protest.

“The GNC system probably still needs to raise its adaptability and robustness.” Tomcat frowned as it rapped the table. “The RCS tri-axial attitude stability can still be optimized. It can still be optimized further…”

Seventy-five seconds after the atmospheric entry.

Mai Dong sat silently in her seat, raising her hand from time to time to look at the time.

Tang Yue had told her that the atmospheric entry would be a terrifying period of sharp deceleration during the real descent. The immense pressure would press her down against her seat, preventing her from moving. During this period of time, she wouldn’t be able to raise her arm. Only after the deceleration was complete, allowing the spacecraft to reach a uniform speed would she be able to move her body.

That six minutes of deceleration was a critical period that determined life and death. If any problems were to happen to Orion, it would most likely be then.

“Tang Yue?”

“Yea,” Tang Yue replied. “I’m here.”