In the control center, about five kilometers away from Launch Pad B of Launch Site 39, a large number of people, including Tang, gathered, and farther away, Titusville, where a large number of tourists gathered. Every time the Kennedy Space Center launches a rocket, a large number of tourists gather in this small city, which is only separated from the Cape by the Indian River, because it is the best place to watch the launch of the launch vehicle from the launch site more than 10 kilometers away from this position and angle, and the effect of watching the rocket rise here is even better than watching it from the control center.

At this time, on the banks of the Indian River east of Titusville, at least more than 50,000 tourists have gathered, of course, there are also reporters among them, many long guns and cannons and some long-distance viewing equipment, all ready at this time, just waiting for the fire to break out more than ten kilometers away.

In the control center of the Kennedy Space Center, which is across the river, it is also crowded at this time, except for the control personnel sitting in front, other important visitors are standing in the back half of the control center, staring nervously at the big screen.

The huge white rocket stands on the launch pad five kilometers away, and this heavy launch vehicle has some differences from previous heavy launch vehicles, that is, at the bottom of it, there are four more thick brackets that can be retracted freely.

These four brackets are hidden in the rocket body before the rocket lifts off, and once the rocket body is detached, then when the rocket is recovered for soft landing, these four brackets play the role of supporting the entire first-stage core rocket body.

"Ten minutes to prepare!" With the sound of an electronic sound, all aspects became more nervous, even Houston Linden, which was more than 2,000 kilometers away. In the general control room of the Johnson Space Center, the atmosphere was also suddenly tense.

"Five minutes to prepare!"

At this time, the gas connector and filling connector on the rocket are automatically disconnected, and the connecting plugs of the telemetry system and external test system are automatically disconnected.

"Ready in a minute!"

Then. After 10 seconds of self-test normal, the cable connector will automatically fall off, and the cable pendulum will leave the launch vehicle and swing to a predetermined position. At this time, except for the cable at the bottom of the launch vehicle that is connected by a detachable plug, which is still connected to the ground, all other plugs connected to the ground have been completely disconnected.

"Thirty seconds ready!"

The TT&C system at the launch site and the TT&C tracking stations in various localities were activated.

"Ten Second Countdown, 10, 9, 8, 7"

Seven seconds before launch. High-speed cameras around the launch pad started filming and began to record the rocket's ignition and takeoff.

"6, 5, 4, main engine start 2, 1, ignition!"

In an instant, the engine vent, which had begun to spew flames outward, suddenly spewed out a large amount of blazing flames, and the white flames turned blue the moment they left the vent, and then gradually turned orange, and the high-temperature gas up to several thousand degrees was sprayed directly into the large pool at the lower part of the launch pad, and a large amount of water evaporated in an instant. It turned into a thick white fog, spraying hundreds of meters from the diversion grooves on both sides

Under the surging power of a total of 12 space engines, the 2,300-ton Xingkong-1 began to slowly leave the ground, and at this time, the only cable connected to the bottom of the rocket was pulled off, and the wired control between the rocket and the ground was completely interrupted. This cable is actually quite important, if the rocket engine is found to be not working properly before the rocket ignition leaves the launch pad. The ground can carry out emergency shutdown of the rocket through this cable, which can be said to be the last insurance before the rocket lifts off.

When this cable is completely detached from the rocket body. At this time, the launch vehicle has been completely disconnected from the physical connection with the control center, and the rest is to rely on the automatic program of the computer in the rocket to control the rocket.

The bottom of the huge Starry Sky 1 spewed out white, blue, and orange-red flames tens of meters long, this kind of flame mixed with three colors was in a section, the inner and close to the vent flames were almost transparent white flames, and the outer ring and the middle turned blue. The outermost and lowermost flames are red and orange.

After the rocket body weighing more than 2,300 tons slowly left the ground, it quickly rose into the air under the surging power of the engine, and in just a few seconds, the rocket broke through the speed of sound from zero speed. The rocket's speed would then continue to increase until the rocket's engine accelerated the behemoth to nearly Mach 6.

This process lasts for a short time, only a few tens of seconds, and in this short tens of seconds, the rocket will complete a series of programmed turning actions under the control of the control system, and finally adjust the flight attitude of the rocket to the best before the first-stage rocket disengages.

This period of time is also the time when the rocket is most prone to problems, and more than ninety percent of the previous launch vehicle launch failures are at this stage, so as long as the launch vehicle can pass this stage smoothly, it almost means that the entire launch process has been successful.

In this short period of tens of seconds, the change of the rocket's flight attitude was completed very well, and there was no mistake at all, which made Dr. Schmitz, who had been clenching his fists beside Tang Feng, slightly relieved, although the next action is the focus of this experiment, but to make the rocket safely lift, this is more important than rocket recovery.

Rocket recovery can fail, but it must not fail to launch, successful launch is the most fundamental task of a launch vehicle!

Starry Sky 1 is different from Falcon 9, when Falcon 9 is 74 kilometers above the ground, the first stage of the core stage rocket will fall off, and the recovery of the first stage of the core stage rocket at this altitude is undoubtedly much more convenient.

The separation of the first-stage core rocket and the second-stage rocket of the Starry Sky 1 was completed above the Kármán line height.

The Kármán line altitude is 100 kilometers above sea level. The Kármán line is the boundary between the atmosphere and space defined by the International Aeronautical Federation, and the Kármán line is used as the boundary between outer space and the earth's atmosphere.

The detachment of the first-stage core rocket at this altitude has actually reached the limit of the heavy-duty launch vehicle, but it is precisely because the heavy-duty launch vehicle can separate the first-stage rocket body at this altitude that these heavy-duty launch vehicles can send a larger mass of material to a farther orbit.

This is the biggest difference between the Heavy launch vehicle and the Falcon 9.

In fact, after reaching the height of the Kármán line, the gravity here is already very small. With the help of inertia, the detached first-stage core rocket drew a large upward parabola outside the atmosphere under the action of very little gravity, and then began to fall into the atmosphere. (To be continued.) )