Old Cat quickly figured out what was going on. One of the sensors on the Eagle had malfunctioned. It had given the lander's computer an incorrect signal, causing the computer to mistakenly believe that it had reached the predetermined orbit. Thus, it had shut down and abandoned the first-stage rocket early. This was twenty seconds earlier than the predetermined shutdown time.
In other words, the Eagle had shut down its engine 180 seconds after launch.
This mistake could have been avoided. As long as Kunlun Station maintained contact with the Eagle, Kunlun Station would have been able to correct the error in time. Unfortunately, when the computer malfunctioned, the communication between the two parties had been cut off. No one had come to stop the lander's system from going crazy.
Shutting down the engine early was an extremely serious mistake. The result was a failure to enter orbit.
The Eagle had completely failed to enter the predetermined parking orbit. It had entered an elliptical orbit with an apoapsis of 280 kilometers and a perigee of 110 kilometers. Simply put, it had derailed.
Old Cat grabbed his ears in frustration and pinched them … Damn it, he had just praised this kid for being obedient. How did this problem occur in the blink of an eye?
This was going to be troublesome.
Tang Yue hugged the antenna and staggered back.
He placed the antenna on the floor and sat down to catch his breath. "How was it?
Did that kid succeed? "
Old Cat turned around. "Succeed my ass. Your son is about to be shot by the Germans."
Tang Yue jumped in fright. "What?
What happened? "
He did not even have time to take off his Bright Light Armour. He scrambled over and leaned in front of the computer screen, his entire body emitting cold air.
The computer had already displayed two trajectories. One was the predetermined orbit of the outer circle, indicated by a red dotted line.
The other was the actual orbit of the Eagle, indicated by a solid blue line.
Clearly, the altitude of the actual orbit was lower than the predetermined parking orbit.
"Right now, the Eagle is only at an altitude of 280 kilometers."
Old Cat pointed at the cursor on the computer screen. "But it should be 350 kilometers high."
"Is it very troublesome?"
"Very troublesome."
The Old Cat nodded. "This little thing did not enter the correct parking orbit, which means that all our previous plans have been scrapped. The subsequent orbit change and rendezvous procedures have to be redesigned. Because the initial orbit altitude is too low, we have to spend more propellant to accelerate … But that's not the most troublesome thing."
Tomcat nimbly dragged the mouse and zoomed in on the image. Then, it pointed out the other end of the orbit to Tang Yue. "This is the orbit's perigee, which is also the place with the lowest altitude. Its altitude should be 150 kilometers, but it's only 110 kilometers now … This altitude is too low."
"110 kilometers has already entered the atmosphere. Although the atmosphere at this altitude is very thin, it will still produce resistance."
The Old Cat explained, "Every time the Eagle passes a perigee, it will expend energy due to the atmospheric resistance. Its altitude will constantly decrease, and the final result will be …"
The Old Cat hit the enter key, and the computer showed the simulation results.
The simulation result was a tight blue spiral that looked like a mosquito coil. This meant that the orbit altitude was constantly decreasing, approaching the surface of Mars, and finally plunging into the atmosphere, burning everything to ashes.
Tang Yue's mouth was agape, and he was stunned for a moment before he realized that he had broken out in a cold sweat.
"We have to change its orbit as soon as possible!"
"I want to too, but we can't let the Eagle accelerate recklessly."
The Old Cat said, "Don't forget that we don't have enough propellant. The consequences of recklessly accelerating will only turn the lander's payload module into a piece of trash in space."
"How much longer?" Tang Yue asked. "How much longer does the lander have?"
"The Eagle's current operational cycle is fifty-three minutes. It orbits Mars every fifty-three minutes."
The Old Cat answered, "Before it descends to the lowest safe altitude, it can still fly around Mars …"
The Old Cat entered the parameters on the computer, and the computer quickly showed the results.
"Sixteen orbits."
Sixteen orbits.
One orbit took fifty-three minutes, so the Eagle had fourteen hours left.
They had to make the lander change its orbit within fourteen hours and leave this orbit that would eventually lead to death. Time was tight, but this was something that could not be rushed.
Tang Yue and the Old Cat both stared at the Eagle on the screen. The Old Cat pulled the image slightly further away, allowing the second orbit to enter their field of vision. Another cursor moved slowly on the orbit. This was the orbit of the Joint Space Station, an elliptical orbit at a higher altitude. The perigee was 380 kilometers, and the apogee was 480 kilometers.
The Joint Space Station's operational cycle was one hour and twenty minutes. Fourteen hours was only enough for it to orbit Mars ten times.
"Within these fourteen hours, there are only seven suitable orbital change windows."
As the Old Cat spoke, it stretched out its paw and pointed at the apogee of the lander's orbit on the screen. "The linear speed of the lander at the apogee is 3.2 kilometers per second. According to the normal orbital change method, it should accelerate at the apogee and then enter a new orbit …"
The Old Cat tapped on the keyboard, and the Kunlun Station's computer system gave the results of the calculations.
A brand new circle was drawn and marked in an eye-catching bright yellow color. It was placed outside the elliptical parking orbit of the Eagle, and the parking orbit was inscribed with it.
The intersection of the two inscribed circles was the place where the lander would accelerate its transfer.
To put it simply, if the Eagle accelerated at the apogee of the parking orbit and ignited the upper stage rocket, it would enter a circular orbit about 280 kilometers above the ground. However, it would not be able to dock with the Joint Space Station in this orbit because the latter's orbit was at a higher altitude. The perigee of the Joint Space Station's orbit was as high as 380 kilometers.
Therefore, the Eagle still needed to perform a second orbital change.
It needed to accelerate again.
The second acceleration required the upper stage rocket to give the Eagle a push, allowing the lander to jump into the space station's orbit.
This was the safest method. Using two intermediate orbits to perform two accelerated orbital changes was the most widely used orbital change method.
"But doing this is very risky."
The Old Cat shook its head. "Using two intermediate orbits to perform two orbital changes seems to be the safest method, but it also consumes the most propellant. If we adopt this strategy … then we will use up all the propellant in the Eagle."
"If we perform two orbital changes, how many times can we dock and rendezvous?"
The Old Cat raised a paw and said slowly.
"One time, at most one time."
One time.
Tang Yue's hands and feet were a little numb. There was only one chance to try, so the success rate was only 5%.
It was either succeed or die trying.