Vol 2 Chapter 460: Daylight meteor

Latest URL: Under the watchful eye of everyone, the rocket drew a white smoke line in the blue sky. As the breeze blew, the smoke lines began to dissipate.
And the rocket, flying higher and higher, to the end there was only a flashing bright spot. If it were not for the sky to be clear and clear, it would have disappeared into the public's field of vision.
"21070 meters, the rocket started to land!"
"The optical tracking observation team reported that the heat shield at the top of the rocket had been detached and the guide umbrella had been thrown."
"Pay close attention to the rocket landing attitude!"
"The grid plate is open, the posture is normal!"
"21000, 20000, 19000 ..."
As the broadcasted figures gradually fell, everyone also clearly saw the figure of the rocket falling. The rocket was like a daytime meteor, dragging a faintly visible wake, and fell to the ground.
"16000, the main umbrella is thrown!"
"The optical tracking observation team reported that all three main umbrellas were open and in a normal condition."
Papapap ... Everyone in the control center and outside watching this scene applauded warmly. As long as the main umbrella is open, this means that most of the return experiment was successful, and the next part waited for the rocket to land.
And Wu Hao, they can see through the naked eye that the rocket dragged three huge red and white parachutes and started to descend slowly. At this moment, the people in the control center also ran out. Everyone looked up at the sky and watched the rocket slowly descend.
"Affected by the increase in wind speed at high altitude, the rocket started to drift northwest."
"How much is it?"
"Expect about a kilometer."
"Continue to observe closely and notify the ground recovery team to prepare for the relevant area to prepare for the rocket's fall."
Upon hearing this order, Wu Hao beckoned and said, "Let's go, let's go to the scene to see."
Zhang Jun nodded, then boarded an off-road vehicle with Wu Hao and then raced towards the place where the rocket fell.
After their car, they followed many other cars. Sitting in the car, Yu Chengwu urged the driver to hurry up, while holding the walkie-talkie: "Anything can happen when the rocket is landing, and there is still a lot of fuel remaining inside the rocket. Yes, so inform everyone to keep a safe landing distance to avoid possible danger.
When it landed safely, immediately set up a separation line, except for professionals, forbid anyone to approach. Especially Mr. Wu and Mr. Zhang, they took hold of him to protect them and kept them away. "
Having said that, Yu Chengwu shouted at the driver in front: "Hurry up!"
Wu Hao. To be honest, they were uncomfortable in the car. While they were close to the window watching the falling rocket in the sky, they had to endure the bumps of the vehicle driving on the sand dunes.
This guy Zhang Jun couldn't stand it after a few bumps, his face was pale, and he was holding it back.
Fortunately, this time did not last long, and the vehicle stopped on top of a high dune. Many vehicles have been parked on this dune, these are the members of the ground recovery team.
At this moment, the rocket was very close to the ground, and visual inspection also had an altitude of 800-900 meters. The approximate landing site was in the sand about a hundred or two hundred meters in front of them.
Everyone can no longer move forward from this distance, who knows whether there will be problems with the height of five or six hundred meters.
"Mr. Wu, why are you running so fast?" Yu Chengwu got out of the car panting, and then angrily directed at Wu Hao.
"Oh, I just want to see it at the scene. If you are busy with you, don't care about us, we will take care of ourselves." Wu Hao smiled back, and then glanced over there and drank water Zhang Jun.
"Come down, get down." Someone shouted at this time.
This shouting focused all the attention on the growing rockets and parachutes overhead.
Zhang Jun, who was pale, walked to Wu Hao at this moment, and then looked at the rocket above his head seriously.
I saw the rocket slowly falling under their gaze, and everyone's heart was mentioned on their throats.
This time before the landing, the rocket engine's ignition and reverse thrust is very important. If it fails, even if there is a parachute, the rocket will crash because of too fast speed.
According to design requirements, after the main umbrella is opened, the rocket will descend at a speed of 9 meters per second. Although this speed is much slower than free fall, it is still very fast.
Although the area of ​​the parachute can be further increased to further reduce the landing speed, it will also cause some other problems.
First of all, the increase in the area of ​​the parachute means that the volume of the folded parachute will increase, and the weight will increase. It also means that the rocket will bear more extra weight, which will increase launch costs.
Second, the larger the area of ​​the parachute, the larger the wind surface, and the greater the influence of the air flow. In this way, the rocket is more sensitive to the influence of the air flow when landing. The wind speed is slightly higher, and the rocket may be deflected by the parachute. This affects landing accuracy, and may even cause problems such as recovery failure.
Therefore, the size of the parachute and the weight of the rocket must be controlled at a relatively balanced point. When landing, it must be neither too fast nor too slow.
To this end, scientists installed a rocket reverse thruster at the tail of this type of returnable spacecraft. In order to start the rocket to accelerate the deceleration immediately before the spacecraft landed. When the spacecraft is landing, it can reach a lower speed that can withstand, and protect the spacecraft from being damaged due to falling too fast.
Take the first rocket body of the return rocket they tested this time, it will instantly ignite the engine at about ten meters from the ground ~ EbookFREE.me ~ and make the engine's thrust reach the maximum in an instant.
However, these engines that are close to the original are definitely not enough. The design team also has three small solid fuel rockets on the three sets of landing gear of the rocket to provide additional thrust.
The height of ten meters is still very high for us, but it is also the height of the rocket itself. And the speed of the rocket's descent is nine meters per second, which means that the rocket has only one second of response time.
In this second, the rocket engine must be fully ignited. This will have very demanding requirements not only on the arrow control system, but also on the reliability of the rocket.
Either all fired successfully and the rocket landed safely, or the fire failed and the rocket landed and crashed.
At the same time as Wu Haoyu, a huge parachute appeared in front of him, and the rocket under the parachute quickly fell under the attention of everyone.
Then, when approaching the ground, the tail engine suddenly ignited and emitted a huge flame, and this flame also rolled up a huge dust on the ground mixed with the smoke generated by the combustion and immediately enveloped the rocket.