Die on Mars

Lao Mao quickly figured out what was going on. There was a problem with a certain sensor on the Eagle spacecraft. It gave an incorrect signal to the lander computer, causing the computer to mistakenly think that it had reached the predetermined orbit, so it moved ahead of schedule. The first stage rocket was shut down and jettisoned, twenty seconds before scheduled shutdown.

In other words, the Eagle spacecraft turned off its engine one hundred and eighty seconds after launch.

This error could have been avoided. As long as the Kunlun Station maintained contact with the Eagle spacecraft, the Kunlun Station could correct its error in time. However, unfortunately, when the computer error occurred, the communication between the two parties was interrupted, and no one came to stop the lander's system from going crazy.

Shutting down the engine early is an extremely serious mistake and will result in failure to enter orbit.

The Eagle spacecraft completely failed to enter the planned parking orbit. It entered an elliptical orbit with an apogee of 280 kilometers and a perigee of 110 kilometers. To put it simply, it derailed.

The old cat grabbed his ears in annoyance and pinched them... Damn it, he just praised this kid for being obedient, why did something go wrong in the blink of an eye? Now we're in big trouble.

Tang Yue staggered back holding the antenna.

He put the antenna on the floor, then sat down and gasped: "How was it? Did the kid succeed?"

The old cat turned around and said, "Succeed, your son will be shot by the Germans soon."

Tang Yue was startled, "What? What happened?"

He didn't even have time to take off his Mingguang armor, so he rolled over and got in front of the computer screen, with air-conditioning emanating from his whole body.

The computer has already displayed two trajectories. One is the planned orbit of the outer circle, represented by a red dotted line.

The other is the current actual orbit of the Eagle spacecraft, represented by a solid blue line.

It is obvious that the actual orbital altitude is lower than the intended parking orbital altitude.

"The current altitude of the Eagle spacecraft is only 280 kilometers." Old Cat pointed to the cursor on the computer, "But it should have been at an altitude of 350 kilometers."

"Is it troublesome?"

"It's very troublesome." Old Cat nodded, "This little thing didn't enter the correct parking orbit, which means that all our previous plans were cancelled. The subsequent orbit changes and rendezvous procedures had to be redesigned, because the height of the initial orbit was too high. Low, we have to spend more propellant to accelerate...but the most troublesome thing is not this."

The old cat quickly dragged the mouse to enlarge the image, and then pointed to the other end of the orbit to Tang Yue, "This is the perigee of the orbit, which is the lowest altitude. Its altitude should have been 150 meters." miles, but it is only 110 kilometers now... This altitude is too low."

"One hundred and ten kilometers have entered the atmosphere. Although the atmosphere at this height is very thin, it will still produce resistance." Lao Mao explained, "Every time the Eagle spacecraft passes perigee, it will consume energy due to the resistance of the atmosphere. It The height will continue to decrease, and the final result is..."

Lao Mao hit the Enter key, and the computer gave the simulation results.

The simulation result is a tight blue spiral that looks like mosquito coils, which means that the orbital altitude is constantly decreasing, approaching the surface of Mars, and eventually plunging into the atmosphere, where everything will be burned to ashes.

Tang Yue opened his mouth and was stunned for a long time before he realized that he was breaking out in a cold sweat.

"We have to derail it as soon as possible!"

"I think so too, but we can't let the Eagle spacecraft accelerate recklessly." Old Mao said, "Don't forget that we don't have enough propellant. The consequences of random acceleration will only make the payload bay of the lander turn into a monster in space." A piece of trash.”

"How long will it take?" Tang Yue asked, "How long will it take for the lander?"

"The current operating cycle of the Eagle spacecraft is fifty-three minutes. It orbits Mars every fifty-three minutes." Old Cat replied, "It can still fly around Mars before lowering to the lowest safe altitude... "

Lao Mao entered the parameters into the computer, and the computer quickly gave the results.

"Sixteen laps."

Sixteen laps.

One lap is fifty-three minutes, so the Eagle spacecraft has fourteen hours left.

They had to change the orbit of the lander within fourteen hours and leave the orbit that would eventually lead to death. Time was very tight, but damn, this was something that couldn't be rushed.

Tang Yue and Lao Mao both stared at the Eagle spacecraft on the screen. Lao Mao zoomed out slightly to allow the second orbit to enter their field of vision. Another cursor was slowly running on the orbit - this is the orbit of the United Space Station. , a higher elliptical orbit with a perigee of 380 kilometers and an apogee of 480 kilometers.

The operating cycle of the Joint Space Station is one hour and twenty minutes. Fourteen hours is only enough for it to fly around Mars ten times.

"Within these fourteen hours, there are only seven suitable orbit change windows." said the old cat. It stretched out its paw and pointed at the apogee of the lander's orbit on the screen. "The linear flight speed of the lander at the apogee is 3.2 per second. kilometers, according to the normal orbit change method, it should accelerate at apogee and then enter a new orbit..."

The old cat tapped the keyboard, and the system computer at Kunlun Station gave the calculation results.

A new large circle was drawn, marked in eye-catching bright yellow, and placed outside the oval parking orbit of the Eagle spacecraft, with the parking orbit incising it.

The place where the two circles meet inscribed is the place where the lander accelerates its transfer.

To put it more simply, if the Eagle spacecraft accelerates at the apogee of the parking orbit and ignites the upper-stage rocket, it will enter a circular orbit more than 280 kilometers above the earth, but it will not be able to communicate with the joint space station on this orbit. The docking is carried out because the orbit of the latter is still higher, and the perigee of the orbit of the Joint Space Station is as high as 380 kilometers.

Therefore, the Eagle spacecraft still needs to undergo a second orbit change.

Use force to accelerate again.

Accelerate for the second time, and let the upper-stage rocket push the Eagle spacecraft again, so that the lander can jump into the orbit of the space station.

This is the most reliable method. Using two intermediate tracks to perform two accelerated orbit changes is the most widely used orbit change method.

"But it's very risky." Old Cat shook his head. "Using two middle tracks and making two orbit changes seems to be the safest, but it also consumes the most propellant. If we take this decision... then We're going to use up all of the Eagle's propellant."

"If we make two orbit changes, how many times will we be able to rendezvous and dock in the end?"

The old cat raised a paw and said slowly.

"Once, at most, once."

once.

Tang Yue's hands and feet were a little numb. He only had one chance to try, so the success rate was only 5%.

If you don't succeed, you will be benevolent.