I ask you to build tractors, but you build rockets?

"lift off!"

A newly built Falcon 9 rocket lifted off from Cape Calaveral with the spacecraft code-named "Dragon-Gravity". This was an unmanned launch.

Almost a year ago, Musk proposed the "flexible gravity solution". After a long period of development, Lockheed and SpecaX turned it into a reality.

In fact, the most basic and important rope technology is easy to solve. The Dragon spacecraft weighing less than 20 tons has a mass of less than 10 tons at one end after being separated. The centrifugal force of rotation can be easily solved.

The FGD part was solved in three months, but the design of the spacecraft required major changes, which took more than half a year.

The original cabin design of the Dragon spacecraft did not consider the issue of gravity. In order to allow astronauts to obtain the correct direction of gravity, a re-docking in space was required.

After entering space, the command module must detach from the service module, rotate 180 degrees, use the top cable to dock with the service module to deploy the module, and then release the cable to a predetermined length to start rotating.

Re-docking means that the command module needs to be improved, and special attention must be paid to the docking part. After all, it has to bear the extremely large centrifugal force during rotation.

Then there is the attitude control system, which is as important as the cable system, that is, a powerful RCS. The service module must have it, and the command module must have it. That is, they provide the speed of rotation and stopping. They must be precise enough and work for a long time.

Finally, there is the issue of trimming the rotation of the entire system, which is the biggest trouble in the design.

Although the weight difference between the two parts is not large, under high-speed rotation of 2 revolutions per minute, a small weight difference or uneven center of mass will cause the attitude or orbit of the entire rotating body to deviate.

But the mass and center of mass of both the service module and the command module are changing in real time. The former is constantly consuming fuel, and the latter has people walking around inside.

The changes in the center of mass of the rotating bodies at both ends are unpredictable, so the computer that controls the RCS needs to be able to respond in time and intervene in time when the attitude exceeds the set limit. However, generally it will not work as long as there is no major problem, because the RCS needs to save fuel. Use it.

The essence of the entire FGD system lies in this automated attitude control system, which is much more difficult than the material of the rope.

The launch mass of the "Gravity Dragon" spacecraft obtained more than 10 months later reached an unprecedented 19 tons, which is more than 30% higher than the original Manned Dragon. Therefore, the Falcon 9 rocket that launched it cannot be reused, otherwise the transportation capacity will not be available. Meet the standards.

Musk originally planned to use a longer-serving Falcon 9 to perform the mission, but Lockheed was afraid that the spacecraft it had finally built would be destroyed by the N-hand spacecraft, so it insisted on wasting a new rocket.

At 8 o'clock central time on the 22nd, mankind's first artificial gravity spacecraft arrived in low-Earth orbit.

Houston spent three hours checking the overall condition of the spacecraft and then confirmed re-docking.

The command module and the service module were gently separated. In the past, the two were connected by explosive bolts that could only be used once. Now they have been changed to a ring-shaped interface that can provide high strength. In order to free up the cable link part in the middle, A lot of effort was spent on the interface.

The separated command module first turned 180 degrees with the help of RCS, turned its head towards the command module and then threw away the top cover, exposing the cable release end interface.

This was originally the docking port of the spacecraft, but now this situation obviously does not have the ability to dock with other spacecrafts. Lockheed's solution to this problem is to change the side exit into a docking port, but this "Gravity Dragon" is No.

It took another hour and a half to complete the docking.

Houston continued to check various parameters, and it was not until 16:00 that the rotation test was confirmed.

The rope used by "Gravity Dragon" is a braided net hollow design, which is very space-saving and has very high tensile strength. Each thin rope is wrapped in a multi-layer structure, and the design redundancy reaches 500%. The instantaneous maximum bearing capacity is higher, so there is no need to worry about the rope breaking.

The two re-docking modules began to gradually pull apart under the action of RCS, and the gray-white cable between the two was slowly released. It has a total length of 220 meters, which can be used without the astronauts feeling obvious dizziness. It produces a comfortable gravity of 0.5G, but the total weight is not as heavy as Musk before losing weight.

Releasing the rope is a slow and careful process. If it is released too fast, the two parts will move irregularly in opposite directions under the stress of the rope. The speed must be accurately controlled. The releaser is also capable of measuring real-time tension. detection device.

The entire release process took a long four hours, and it had already entered Ami's summer night.

The new director Robert was present in person. Of course, "Gravity Dragon" is also strongly supported by NACA. If it can win the first successfully operating artificial gravity device in mankind, it will definitely be a great thing that can be touted in front of Congress.

Because the cable release process was very careful, the relative position of the command module and service module is now quite good, almost in a perfect straight line, and the cable is basically straight but not stressed.

Musk, who was still in Florida, also connected remotely through the control room there and said into the phone:

"Let it spin, Mr. Director, I have confidence in it - not confidence in getting the experimental data, I am sure it will work."

Robert nodded and gave the order to increase the rotation speed to 1 revolution per minute. If the cabin can generate a gravity of about 0.1G, the speed can continue to increase.

After the command from the ground is issued, the respective RCS systems of the command module and the service module first release gas in the outward direction to tighten the rope to the predetermined tension, and then, under everyone's expectation, in a direction of about 85 degrees to the rope Producing an opposite thrust, it began to rotate around the non-existent central axis.

1 revolution per minute, then the speed of the rotating body is 11.5 meters per second. This speed is very easy to achieve. Even if the RCS has been started at the minimum power, the speed of the two cabin sections is still rapidly increased, and it will be over in less than 20 seconds. Each turns off the RCS of the direction of motion.

In an orbit at an altitude of 400 kilometers, two spacecraft each weighing about 9.5 tons are connected by a cable and orbit around like a binary star system.

The gravity meter placed in the command module is accurate to the third decimal place, and its display number now jumps back and forth between "0.121" and "0.127".

Let’s look at the stability of the entire rotating system. According to the detection of the ground antenna array, no obvious orbit deviation was found, indicating that the RCS system successfully controlled the symmetry of the rotating body.

Now, mankind's first artificial gravity system is officially put into use.

There were simultaneous applause and cheers in Houston and Florida.