SpaceX's Falcon 9 crashes and lands in the water

Today, SpaceX has made its 20 launch in the year. Like the 19 others, the mission given is the mission accomplished. The Dragon capsule was placed exactly on orbit to find the space station and deliver more than three tons of supplies, experiments and mouse food. More a few thousand verses. The only negative was the landing of the first leg of Falcon 9. The latter had an anomaly.

To understand what happened, we first need to understand the complexity of landing a Falcon 9, something no one else in the world does; Rockets are like a 0-km truck that delivers a refrigerator and is then thrown into the sea.

Not so simple, a rocket reversing its course is the least natural act that one knows man or woman, if it is Katherine Johnson or Gwynne Shotwell.

SpaceX has two maneuvers to land. When the mission consumes a lot of fuel, the Falcon 9 follows a parabolic trajectory and lands on the raft. If the mission is less noisy, it resumes its direction and lands in the same region where it was launched:

For the return to the launch site, Falcon 9 performs the following maneuvers: [19659005] 1 – Guided tour 180 degrees and triggers three of its nine Merlin engines, which cancels the horizontal speed and changes the direction of its movement. It uses only three engines because it is much lighter, without charging the second stage or most of the fuel used before.

2 – When the Falcon 9 begins to fall to the landing, it begins to accumulate speed. So that it does not go down too fast and does not burn during the re-entry, it performs what is called re-entry, which triggers the engines again.

3 – In the last moments of the landing, the Falcon 9 remains supersonic. It has to slow down, but it is so light that even a single, minimal power motor would make it go up, though it was pulled to the ground. The descent is calculated so that the deceleration caused by this engine causes the Falcon 9's speed to be zero when the altitude is zero.

A rocket can be modified in four different ways, but it does not seem to work properly.

A rocket can be modified in four different ways The aeronautical experience led the designers to use the same control methods: a stabilizing surface with a moving part that modifies the air flow and, thanks to Newton, the rocket moves in the opposite direction. Note the end of the fins of this rocket V2, the moving bits. The problem here is that the higher you climb, the less the rudders have aerodynamic authority, and in the void, they are more useless than your brother-in-law, the pointless.

Another way to control the direction of a rocket is to change the output of the escapement, if instead of following the velocity vector of the rocket, the exhaust tilts, the corresponding. the movement is applied to the rest of the rocket. This can be done with fins through the exhaust, like the V2. Of course, this does not work for larger rockets and with warmer exhaust gases. Then the solution is to move the integral engine cap:

The disadvantage is that it does not work for subtle maneuvers and the engine must be on. Engaging the main engine when you engage with the Space Station is a great way to get a kick in the bad and never drive a vehicle as powerful as the Lada.

3 – Vernier Engines

The idea here is to use vector thrust. but fixed. Vernier is a name given to small auxiliary engines driven at variable power, generating an unbalanced thrust, forcing the rocket in a certain direction. They are also used to avoid scenes at the time of separation, as in Saturn V.

Here, a Soyuz propeller, note that there are four Vernier engines around the main engines.

The disadvantage is that they are heavy, complex and consume a valuable fuel.

4 – Maneuvering Jets

Vernier engines are cool, but placing engines where the rocket needs to turn would make everything expensive and complex. Sometimes a precise adjustment is needed, and this is done with low power jets scattered around the boat. The Apollo landing module had 16 maneuvering engines:

Nevertheless, 16 engines did not increase their weight as much as they were extremely simple. They used hyperglycemic fuel, a clbad of substances that come in contact with an oxidant, ignites automatically, without depending on external factors.

SpaceX (and everyone else) uses something simpler: jets of maneuver. Cold gas C is simplicity in person, a gas tank under high pressure, usually nitrogen, a solenoid valve and an exhaust tip.

I I said that he had to do everything by always calculating the speed of descent to reach the ground at 0 km / h.

I do not know where to start such software, and I'm pretty sure it's not done in PHP, but whatever the technological mess used by SpaceX users, it worked much more than expected. The software corrected the rotation at the last moment and almost landed in the water:

In this video, you can see how the vector buoyancy is used to the maximum, the engine Correcting the rotation and tilt at the last moment:

According to Elon Musk, the four networks use the same hydraulic system, with the same pump, when the pump stopped working . Since it is not an essential mission system, there is no redundancy, but it intends to install a second pump and a new one. set of hydraulic lines, so that never happens again.

The Falcon 9 is always better than its competitors. . After landing in the sea, he continued to float and send telemetry like a good boy.

For the moment, he has already sent a ship to inspect the rocket and, just a few hours ago, the aircraft still floated very badly, waiting for the engineering team to strike at the head to know how.

While if we ignore the very experimental landing of the Falcon Heavy's central servomotor, there will be THREE successive landings. You can say that SpaceX is used to bad people, but the best part is that they themselves are not happy. Even a secondary point, such as the landing of the rocket, must always be perfect, and that is apparently what will happen.