There’s no north or anything, are there coordinates or you just point at a planet and go for it?
In: Physics
The US has ground stations with radar transmitters and receivers at 3 places on Earth.
This is called the Deep Space Network.
It sends a radio signal to the probe, the probe shifts the frequency and transmits it back.
By comparing the signal, the shift, and what got back, they can use math and physics to figure out where the probe is.
Stars or Pulsars. Both are common waypoints for a civilisation trying to cross the galaxy. On the golden disc we sent on Voyager 1 [I think?] It has a pulsar map leading to Earth.
[Here you go.](https://youtu.be/YAnxt1YPWbk). Curious Droid did a great video on exactly this.
You have to lead your shot. Thankfully, space bodies are very predictable, so you can use math to always know where it will be.
As for turning which way and how far, your own spaceship has a top/bottom/front/back/left/right. There’s a special vocabulary, like prograde/retrograde, etc., but your turns and burns will be given in degrees related to where your spaceship is already pointing.
No, you can’t just point at a planet and “go for it”. For two main reasons.
The first is that if you pointed at where you needed to be, you would never get there. Space travel is unintuitive. Nothing goes in a straight line because there is always some planet or moon (and the Sun) bending the path. For example, instead of pointing straight up, you need to point sideways and accelerate in oder to get further from the surface. If you did point straight up, you would get further away, temporarily; until your fuel ran out. Then after coasting to a stop you would fall back to the surface.
The second reason is that planning a route takes a lot of work. Most of the weight of a spacecraft is fuel. It takes a tremendous amount of fuel to get something into space. Missions are very carefully planned to uses the least possible amount of fuel. It is very common for deep space missions to fly close to a planet(s) in order to steel a little bit of velocity from it. That’s called a “gravity assist”. Sometimes making many passes – each time increasing velocity so that it can reach a higher orbit.
A combination of Inertial Navigation, Radio Navigation and Astro Navigation are used to keep track of position.
Inertial Navigation is keeping track of your speed and direction using very sensitive devices. It is accurate in the short term but it needs to be updated using other methods.
Astro Navigation is using distant stars to figure out your orientation. This is very accurate in determining where you are pointing but less so in pinning down exactly where you are. Planets, moons or other bodies can also be used.
Radio navigation can determine very accurately how far you are away from Earth. Basically by timing the radio signals.
I out solar system you use the [Ecliptic_coordinate_system](https://en.wikipedia.org/wiki/Ecliptic_coordinate_system)
The sun is ins the center and the zero plane is the orbit of the earth. That makes it simpler for us to use. The direction is measured relative to the stars. The relative moment of start is minuscule in our solar system, the closes might shift a fraction of a degree so you do not use the.
There is north for orbits too it is an [Orbital_pole](https://en.wikipedia.org/wiki/Orbital_pole). You use the right-hand rule. Take the right hand and curve your finger and point up with your thumb [like this](https://en.wikipedia.org/wiki/Right-hand_rule#/media/File:Right-hand_grip_rule.svg). If the finger curves like the orbit the tum point to the orbital north.
For position in the solar system, you look at the angle of planets and the sun relative to the stars and you can determine location. Radio communication from earth has delays and you can get the distance to earth and the speed from the doppler shift.
You do not point to a planet to go there. You make a burn so you and the planet arrive at the same time. You can compare to if you would throw a ball to someone that is running. You aim to a point in front of them so they meat there. If you aim at where they are you will miss them.
Navigation and positioning in space (far from earth) is typically done by tracking your position as it relates to stationary or plotted objects like stars or planets https://en.wikipedia.org/wiki/Star_tracker
In summary, you see specific planet out a specific window, this acts as a point of reference, with a few you can triangulate, with computers doing calculations many times a second it can be very accurate.
There are other methods too, including Transponder pings, GNSS sattelites, inertial sensing, dead reckoning, etc https://en.m.wikipedia.org/wiki/Positioning_system
and yes when “aiming” for a specific planet, you actually aim at empty space ahead of it’s path, to intercept catch up to it months later on opposite side of solar system at good angle and speed
It’s highly dependent upon where you’re going! Aerospace engineering student here, and essentially you base your location entirely off of other celestial objects but there are hugely different “frames of reference” to choose from. For example, if you’re just trying to go from the earth to the moon, you consider the three-dimensional origin to be the center of the Earth and then the moon is in orbit around the Earth and you can track your location relative to the Earth. You still have to account for atmospheric drag, solar radiation pressure, and gravities of the moon and sun but that’s the gist.
However, if you are trying to move from the Earth to Mars, then you want your three-dimensional origin to be centered on the sun and then you launch from the Earth aiming at a currently empty point in space where the math tells you Mars is going to be in the ~6 months that it takes to get there. This way, your location, the Earth’s location, and Mars’ location are all defined in relation to the position of the Sun so you can determine where all three objects are currently and where they will all be in 6 months or whatever it may be.
An interesting point here is that contrary to TV you don’t just fly straight towards another planet in a rocket. Increasing your speed in an orbit also increases the distance of the orbit trajectory from the object you are orbiting around. Thus, you can increase your speed so high that you exit the orbit but you’re still moving in an elliptical trajectory (oval-shape) so you basically slingshot out of Earth’s orbit towards the point in space where you need Mars to be, which means there are certain windows of time where it’s not actually possible to make the journey because Mars simply wouldn’t be where you want to end up and there’s no possible way to reach it at that time. This is due to the difference in distance from the Sun of the planets and also how fast those planets are moving around the Sun, but you can actually pretty precisely calculate the window of possibility for when you can make a journey and space missions are generally designed to be well well WELL within the window as absolutely every possible safety precaution is taken.
Well, i just think of a place and I’m there, it is more a positioning situation than a travelling one.
you point at where the planet will be when you get there because it will move while you are moving toward it. its just a bit confusing because you’re moving from one frame of reference to another, going to the moon for example, you’re moving from the earth being your frame of reference to the moon being the frame of reference. its a bit like jumping into a car moving 60mph from standing still. if you started running first and made it upto 59mph you could slip into the car with a minor speed differential but you’d probably die doing it from a standstill. or miss. the idea is to match the speed and direction and rendezvous with whatever it is somewhere a long its orbit. you’re matching orbits at least for a period of time so you and the target are on the same trajectory.
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