Check out some interesting facts about rocket launching based on SpaceX Falcon 9 and SpaceX Falcon Heavy takeoff broadcasts.
SpaceX has been very successful in its plan to produce reusable rockets. Until the time of publication of this post, according to the site SpaceX Stats, the company had already made 25 Falcon 9 landings without problems, and 13 missions occurred with retired vehicles.
SpaceX attracts a lot of attention to its releases, probably due to the combination of factors such as …
- The visual spectacle that is a rocket launch and the images of the 1st stage returning to Earth and landing successfully;
- The excitement of the SpaceX team during live broadcasts, which vibrates with every correct procedure;
- The statements of the company’s CEO and space exploration enthusiast Elon Musk, and his dedication to the purpose of bringing the human being to Mars.
After the company sent a car into space in February 2018 aboard the Falcon Heavy rocket, it seems that even more people have turned their eyes to SpaceX. So why not take advantage of this whole scenario to learn about some interesting aspects of a launch event? Good reading!
1. T Minus
If you notice the countdown, you will notice that before the release the counter is marked “T-” and the number on the side. In the case of the image, the counter is in T minus 2 minutes, or “T minus 2 minutes”.
OT represents the moment of release. It is also worth noting that when the meter reaches 0, the indicator becomes “T +” and begins to show the elapsed time after the start of the launch.
At T-1 minute, computers take control of the countdown – an event known as “startup.”
At this point, during the SpaceX broadcast, we can see the warning “The Falcon 9 flight computers have taken control of the countdown”. This means that the rocket’s own systems will check all sensors and indicators and if they detect any anomalies they may abort the launch.
3. LD is go for launch
In some releases, about T-45 seconds, we can hear the phrase “LD is go for launch”.
LD stands for Launch Director, or launch director. Within the control center, he is the professional responsible for making the final decision to let the count proceed or abort the engine ignition – an event also known as “go / no go”.
4. Water jets
A few seconds before launch, you can see a series of water jets towards the base of the rocket. They serve to cool the platform and reduce the damage that intense heat can cause on it.
In addition, they have the function of absorbing the acoustic energy released during the ignition, preventing it from reflecting on the platform and damaging the rocket and / or payload.
The concept of telemetry is as follows: communication process in which a remote equipment transmits data with measurements or other information about its state to an operator or command center. In the case of Falcon 9 and Falcon Heavy, some telemetry data that we can clearly follow during the launch transmission are speed and altitude.
6. Point of maximum dynamic pressure
Shortly after reaching the speed of sound (about 1235 km / h) and just over 10 km altitude, the SpaceX transmission shows that the vehicle arrives at a point known as Max Q, or maximum Q. the message: “Falcon is currently experiencing max-q or maximum dynamic pressure. This is the point where the largest amount of aerodynamic stress is exerted on the vehicle.”
This means that the rocket has reached the point of maximum dynamic pressure – the time when the vehicle suffers the most stress during flight.
To understand what the Max Q represents, we need to understand that the rocket is accelerating to reach space, and as its velocity increases, the pressure on the vehicle also increases. At the same time, we have to remember that the density of the atmosphere decreases as we reach higher altitudes, which reduces the pressure on the vehicle.
That is, there will come a time when it will be fast enough and high enough that the friction with the air causes the maximum dynamic pressure in its structure. After the Max Q, this pressure decreases, as the density of the atmosphere gets smaller and smaller.
Ok, but why “Q” max? Where did this “Q” come from?
It comes from the physical formula below, which determines that the dynamic pressure is given by the letter q, where ρ the density of the air at the site and v the speed of the vehicle.
q= 12ρ v2
7. Main Engine Cutoff (MECO)
The Falcon 9 rocket has two stages.
The 1st stage is the largest, it has nine (and therefore Falcon 9) Merlin engines and is reusable, since it has the ability to land safely after its re-entry into Earth. This allows the company to restore it for use in other releases.
The second stage is smaller, has a Merlin engine specially developed to work in vacuum, is not reusable (at least until the moment of publication of this post) and carries the payload (satellite, capsule, probe, etc.).
For the 1st stage to release the 2nd and return to Earth, there must be the separation event between the two. And before that happens, it is necessary to interrupt the 1st stage engines, which is called the Main Engine Cutoff (MECO), or cut off the main engine – here we consider “engine” as a generalization, which, in fact, refers to all engines of the 1st stage.
Shortly after that cut, a pneumatic system enables separation, as the transmissions usually show clearly.
Did you like the post? Do you know other interesting facts that we can observe during rocket launches? Then share with us. Leave your comment!