how is spacecraft?

We may all have questions about how a spacecraft works and can travel that takes years over the years, how to communicate and what fuel it uses to drive the satellites. There are so many questions like that that come to mind, and start looking for those stories on various websites to satisfy our curiosity. Here I want to share the story hopefully we can keep learning new things, thanks. Maybe useful!!!

spacecraft

^{spacecraft.source}

The easiest way to move from one planet to another, an example of a spacecraft going from Earth to Mars is by utilizing the gravitational force of the Sun.

First, we send the spacecraft out of the Earth using a rocket. These rockets must be enormous (depending on the weight of the rides they carry) as they have to fight the Earth's gravitational forces and also the friction with the Earth's atmosphere in its early stages. To ease the rocket into space, rockets are usually built into several stages, and empty fuel tanks are immediately disposed of. In this way, the load carried becomes lighter.

^{rocket stage,credit image}

Facing Earth's atmospheric drag force

To overcome the problem of interaction with the Earth's atmosphere as the rocket sped from the Earth's surface into space, the trick can be thought through by understanding the drag. The inhibitory force occurs when a solid object moves across the fluid. The Earth's atmosphere can be thought of as a fluid, and rockets traveling through the atmosphere will experience a drag force that is opposite to the direction of the motion of the rocket. The magnitude of this drag is directly proportional to the rocket speed, the faster the rocket the greater the rocket drag. Tricks for coping with drag? The rocket is accelerated slowly, so it moves slowly until it reaches the upper Earth's atmospheric layer, where the atmospheric density is more tenuous and the drag force is consequently lower even though the rocket is rushed. It is at the top of the rocket that the rocket is so rigorously accelerated that it reaches the speed required to escape the gravitational pull of the Earth.

^{The appeal of the Earth's atmosphere,credit image}

We may have heard that an object must reach a speed of 40 320 km / h to be able to escape from Earth's gravitational pull (This number is called escape velocity or the freelance language of freelance). This is true when we are on the surface of the Earth, but if we are already in the upper layers of Earth's atmosphere, the velocity off is slightly smaller.

The rocket fuel to be able to escape from the gravity of the Earth varies, but early versions of the rocket that successfully took humans to the Moon using kerosene burned with liquid oxygen. Yep, kerosene! Certainly, not the usual kerosene sold, but refined kerosene to reach a certain steam point and freezing point. Some other variations use liquid hydrogen which is also ignited with liquid oxygen. The main principle of rocket fuel is that it must be able to produce a chemical reaction that can produce a thrust force capable of lifting the entire rocket load.

Navigation between planets

^{rockets with the pull of the Sun..source}

When the spacecraft has reached the outer space, then the vehicle will fire jet thrust so that it gets the speed to move in a certain direction that has been calculated before. Further movement of the pure rocket comes from the pull of the gravitational force of the Sun. That is, it actually orbits the Sun in an elliptical trajectory, in such a way that its path will be close to Mars. Of course to calculate a suitable path we need to know the current position of the Earth and also the position of Mars in the future. With an understanding of Newton's Law of gravity, this can be calculated, and the most suitable schedule for launching a rocket can be determined.

Gravitational slingshot

Is the motion of spacecraft thus "patent" when it is launched into its path? Meaning this trajectory cannot be disturbed anymore? In principle not, and the plane can still maneuver in the other direction or change its speed. The most efficient way that has been used and need not involve much of the propulsion system of its own (because we know the additional machine will add a load to the rocket at the time of the launch from the surface to the space) is again-by using the energy of the object's gravitational force others passed by the rides.

^{gravity between a spacecraft with a planet.source}

As the vehicle passes through a planet, there is a gravitational interaction between the two. From this interaction arises the movement of momentum from the planet that is moving into the spacecraft. As a result, the spacecraft gains additional energy and hence its speed increases and the direction of its motion changes with the velocity vi, will change direction toward the velocity vf, due to the gravitational interaction between the rides with a planet).

It sounds unreasonable because the speed of the rides before and after the planet has not changed, the kinetic energy obtained by the approaching vehicle should disappear as the vehicle away from the planet. This is true from the point of view of the planet, but we know the planet is also moving at a certain speed relative to the Sun. As a result, when viewed from the frame of reference of the Sun, there is a transfer of momentum from the planet to the vehicle due to the movement of the planet. This means that the planet actually loses its motion energy to be transported to the rides, but this loss of energy is only a fraction of a million of the planet's total energy, because of the difference in mass between planets and rides that are very, very different, hhehehehe ... (racial mass approximately 1 ton = 1000 kilograms, while the planet ranges from 1024 - 1027 kilograms).

^{A "gravity catapult" analogy, illustrated by Charles Kohlhase and Gary Hovland. NASA.source}

A simple analogy can be imagined in Figure on the side. A train travels at 50 miles per hour. A boy then throws a tennis ball at 30 miles per hour. Suppose the collision between the tennis ball and the train is an elastic collision (no energy lost before and after the collision), then the tennis ball will approach the train at 80 miles per hour and will bounce back from the train at 80 miles per hour. this is seen from the point of view of the train driver who is stationary relative to the train. However, from the point of view of the person sitting on the side of the track, the tennis ball will bolt back at 130 miles per hour. Tennis balls gain additional kinetic energy from those derived from the kinetic energy of the train.

This analogy is not exactly perfect because we know the rides are not touching the planet at all, and the movement of momentum takes place through gravitational interactions.

The interaction results between planets and rides can lead to accelerated rides, but can also slow down the rides. This depends on the direction of the arrival of the relative to the direction of planetary movement.

^{Montage of planets and some moons the two Voyager spacecraft have visited and studied,credit image}

Interactions that utilize the gravitational interactions between planets and rides are often called "gravity slingshots", and are the most effective mechanism for changing the direction and velocity of a vehicle. This method has been successfully used by Voyager 1 and Voyager 2, two spacecraft that successfully utilize the gravitational force of Jupiter and then Saturn to gain additional speed that allows them to escape from the gravitational attraction of the Sun. Of course, to schedule, the most appropriate time to launch a rocket requires a very good understanding of Earth's orbit, Jupiter, and also Saturn, as well as mature calculations.

^{The trajectories that enabled Voyager spacecraft to visit the outer planets and achieve velocity to escape the Solar System,credit image}

In other words, the "fuel" of a spacecraft to reach other planets is not just petroleum and liquid oxygen, but also coffee and physics. Physicists whose specialty is astrodynamics and orbit counting can calculate the most suitable trajectory, but without the intake of coffee in the morning frankly want to think to be a bit difficult bro (for some others, cigarettes are also important) .hahhahaha.....

Communication with Earth

^{Space Communications with Mars,credit image}

Radio waves can propagate in a vacuum because radio waves are a disturbance in electromagnetic fields in radio frequencies, and electromagnetic fields are ubiquitous in the universe. Communication between the control room on Earth and the spacecraft is done with radio frequency, but because the distance between the two is very far and the speed of light is moving with infinite speed (in one second a beam of light can travel 300 000 kilometers), the radio signal from Earth time to reach the rides on Mars, and vice versa. The waiting time to between Earth-Mars ranges from 8.5 minutes to 42 minutes, depending on the distance between Earth-Mars.

Okay, bro n sis so the first story of me hopefully can be useful for all lovers of space and also lovers fellow creatures live hehehehe ... hopefully, we can continue to multiply the new and useful science for others. Thanks!!!