Human exploration of the unknown is the cornerstone of the development of human civilization, and it is also the most fundamental reason why human beings can become the overlord of the earth's creatures until today.

It's in our nature to be curious, just as a child likes to put anything in his mouth and bite or lick it, when in fact it is just a matter of checking to see if it is edible and what it tastes like.

This is a kind of biological instinct of human beings, and the act of sending an aerospace plane into space is actually no different from the behavior of a child sending something into his mouth, it is a kind of exploration of the unknown.

"Altitude 23000, speed of Mach 2.8, slope 5, heading due south, aircraft attitude normal, throttle output normal, flight system normal, scramjet engine start preparation."

As Xia Yu's voice ended, the other people in the cockpit also began to get busy, Wang Pengyu confirmed at the same time when Xia Yu began to read, and then contacted the flight control center according to the schedule. Wu Degao, Du Junbao and Wu Min monitored and operated the relevant instruments in their respective positions, and soon, the flight control center issued authorization, Xia Yu and Wang Pengyu both twisted the ignition knob at the same time, and the scramjet engine began to start.

The familiar feeling of pushing the back came again, but this time it was going to be directly advanced to the predetermined 12 Mach speed, and the conversion between the two modalities was also a test, Xia Yu and Wang Pengyu stared at the dashboard in front of them, and took turns to report the readings in real time, when Xia Yu reported the airspeed of Mach 6, Yuan Limin and other people in the Shenlong project team who were far away in the flight control center couldn't help but feel nervous.

"Airspeed Mach 7!" Wang Pengyu's voice came, the ramjet engine successfully entered the scramjet mode, and there was no problem with the conversion between the two modes, but Yuan Limin and the others did not seem relaxed in their hearts, and the test faced by the Shenlong had just begun. As the speed increases, the friction with the air becomes more intense, posing a new challenge to the overall structure of the aircraft and the heat resistance of the fuselage surface.

"The body shakes normally, the engine output is stable, how is the monitoring in the body?" Xia Yu clutched the armrests on both sides tightly and asked without looking back. As soon as the plane enters the cruising altitude, it starts to use autopilot, and when the scramjet engine is started, it is even more difficult to use your own hands to grasp the rudder, because driving manually at this speed is no different from walking on the edge of hell. If the angle of the rudder suddenly shifts too much due to vibration or other reasons during manual control, the huge instantaneous overload force can even be increased to more than 30 G, which is completely beyond the limit of what the human body can bear, and also exceeds the upper limit of the overload force designed by the aircraft itself. The consequences are obvious, all the pilots will be seriously injured, stunned or even killed, and the plane will disintegrate in a huge fireball.

"The monitoring is normal, the body response is normal, and there is no abnormality." The mechanic's answer was reassuring, when the speed of the Shenlong reached Mach 12 and maintained a flight time of fifteen seconds, Xia Yu and Wang Pengyu began to slowly retract the throttle and reduce the speed, and today's test content was basically completed.

Successfully returned to the ground, according to the predetermined plan, the fuselage skin and the leading edge heat-resistant materials of the Shenlong will be disassembled for study, so there will be no test flight activities for at least two months, just in time for the Shenzhou manned spacecraft to be launched again, Xia Yu and a few people rushed to the Jiuquan Satellite Launch Center with the invitation letter given by Yuan Limin.

Jiuquan Satellite Launch Center, located in the western part of Inner Mongolia, is China's only manned space launch site and one of the world's three largest space launch sites. Because when contacting Beijing, 'Dongfeng' is its own code, because it is also called Dongfeng Base. In 92 years, the No. 1 chief was interested in inspecting the Jiuquan Satellite Launch Center and wrote down a few big characters of Dongfeng Space City, and since then, people here have officially called this place Dongfeng Space City.

The Chang'e-5 lunar exploration satellite has been launched at the Xichang Satellite Launch Center some time ago, and Xia Yu and others were unable to catch up with the launch site because of their work. Because the construction of China's space station has reached the final stage, sending people up this time is equivalent to officially opening the space station.

In the satellite launch site, Xia Yu and the others had an invitation letter, so unlike other tourists, they could only observe the satellite take-off in the distant observation area, they entered in advance, and even greeted the three astronauts, and then walked to the exclusive observation area to wait for the rocket to be launched.

If you haven't watched a rocket take off, you can't appreciate how shocking it is when this human-made steel object tries its best to break free from the earth's gravity.

The rocket itself is not that huge, more than 60 meters high and about 3 meters in diameter. But when it was successfully ignited, the smoke that suddenly tumbled up from the ground, the deafening loud noise, and the orange-red tail flame that looked longer than the rocket itself when it detached from the launch pad, seemed to be a sensation that even the soul could not be felt anywhere else except at the launch site.

Until the rocket pierced the cloud curtain and disappeared into the boundless sky, Wang Pengyu and the others seemed to be able to feel their bodies trembling with the air, and Wu Degao, Du Junbao and Wu Min were even more envious from the bottom of their hearts.

The three astronauts who took off they all know each other, they are all comrades-in-arms who have been training and learning together for so many years, and now they have achieved their goals one step ahead of themselves, when can they really go to outer space and really see the earth in space, the home of mankind? Wu Degao and the three of them couldn't help but turn their heads at the same time, and the direction they were looking at was the space plane Shenlong, which was ready to fly in the sky again at any time.

Although I couldn't wait in my heart, in fact, everyone knew that Shenlong should not have any plans to fly to outer space in the short term, so I had to suppress my eagerness and tell myself in my heart that as long as I waited, I would definitely be able to go to space in the envy of others one day.

The five people who rushed to the airport in an off-road vehicle still have a trace of excitement in their hearts after watching the rocket take off, but they don't think that a life full of accidents will always give you a surprise or fright from time to time.