In space there is no GPS or compass, how autopilot can work there?
How to make two spacecrafts find each other completely by computer control?

Isn't it good thing that object will continue to move without changing speed or direction in space?
Would be difficult to travel longer if you would need to steer all time, few days to moon for example, very hard to maintain direct course in such empty space. How about mars then? Few years you have too keep gripping from that wheel

Pythagoraen theorem. 'Nuff said

You just get two satalites, and find the distance between the satalites and the space shuttle. Then, you find the distance between the two satalites, and you draw a line down the center of the triangle. Then you find the length of the third side of the two congruent triangles. That is how you find altitude of a space shuttle. It is actually quite simple geometry when you dumb it down a little.

But how computer finds distance then, by laser I guess?

Flights are precalculated in direction and speed, so there shouldn't be a need for an autopilot. Once in free-space, there is no gravity and hardly any friction so the spacecraft will keep moving on its course.
Also, spacecraft do have compasses. And Fly-By-Wire computers.

http://en.wikipedia.org/wiki/Spacecraft

Quote from JTbo :

But how computer finds distance then, by laser I guess?

No, by using satalites... Just like GPS except in space. Do you understand how GPS works? Invert it and there you go lol.

Quote from (SaM) :

Flights are precalculated in direction and speed, so there shouldn't be a need for an autopilot. Once in free-space, there is no gravity and hardly any friction so the spacecraft will keep moving on its course.
Also, spacecraft do have compasses. And Fly-By-Wire computers.

But what North they will point to? Not earth's north for sure

If I would travel in space and found out some planet system I would like to visit I certainly would like to have some sort of autopilot where I could plot course.
Perhaps better reconsider of that space craft building few more times, sounds complicated

Quote from wheel4hummer :

No, by using satalites... Just like GPS except in space. Do you understand how GPS works? Invert it and there you go lol.

But there is no satellites near Alpha Centauri for example, wouldn't it take too long data to travel such long way ?

It's a GPS compass that uses multiple sattelites to define its 3 dimensional position.

Also, a spacecraft can change its course by orbiting a planet, wich will basically slingshot the craft, bending its direction.
Though, that is a cumbersome method, as I believe spacecraft can alter their direction with so called booster engines.. but I'm not sure. There's little to boost upon compared to being within earth's atmosphere.

You seem really curious about how to build a spaceship.. found some extra cardboard and duct-tape lying around? Good luck.

Quote from (SaM) :

It's a GPS compass that uses multiple sattelites to define its 3 dimensional position.

Also, a spacecraft can change its course by orbiting a planet, wich will basically slingshot the craft, bending its direction.
Though, that is a cumbersome method, as I believe spacecraft can alter their direction with so called booster engines.. but I'm not sure. There's little to boost upon compared to being within earth's atmosphere.

You seem really curious about how to build a spaceship.. found some extra cardboard and duct-tape lying around? Good luck.

Yes, they can change direction and rocket engines does work in space unlike jet engines that do work only in athmosphere.

Ion drive is then what can be used for longer trips, that is very good and promising power source for future space flights.

Current space shuttles are rather useless space crafts compared what is to come as some day we travel in space as we travel now on roads.

Surely there have to be some navigation system possible for use in longer trips, maybe some kind of map that has all stars and planets, then it runs that as simulation so map is always accurate. However again is problem how to know what is position of ship...

Oh no, I got this tinfoil lying around here....

Inertial navigation can be used to know your location, that is using gyroscopes to measure acceleration from which you know where you are if you know where you started. Such systems get drift over time so they aren't perfectly accurate, but you usually dont steer that much, the spacecraft is launched with such a course that it will reach it's destination without much (or any) "steering".

If you know where you've been, you know where your going.

If I let you travel to Alpha centuri under your own speed with you taking note as we went then you would know where you are and how to get back.

If I just picked you up, covered your eyes and your ears and instantaniously transported you there then you wouldn't have a clue where you where. Nothing would look the same and you would have no reference points to work from. You wouldn't even be able to tell me which Star was Sol.

Taking note(s)? I can imagine it on autoroute

1. Turn left after leaving Earth orbit
2. Travel through nothingness at the speed of light for 4.4 years
3. Arrive at your destination

Quote from Bob Smith :

Taking note(s)? I can imagine it on autoroute

1. Turn left after leaving Earth orbit
2. Travel through nothingness at the speed of light for 4.4 years
3. Arrive at your destination

ROFL

Yes, I think currently there is only possibility to travel in space as good as throwing a rock.

Only some kind of system that runs virtual space and updates ship position based on speed and user input might work, but how about when you plot course wrong, virtual space shows you are at jupiter even you don't see any planets nearby, then what?

Science fiction movies are bit lack of realism here

Normally spacecrafts use gyroscopes to establish their own position. its like these toy-ball thingis

Quote from JTbo :

but how about when you plot course wrong, virtual space shows you are at jupiter even you don't see any planets nearby, then what?

Then the mission has failed miserably and the project leader gets fired

Quote from JTbo :

virtual space shows you are at jupiter even you don't see any planets nearby, then what?

What's your point? You think all the mars rovers are faked or some sort of conspiracy theory? Who cares how autopilot works in space, it just does. Someone, somewhere must know how it works. You should do some reasearch for yourself, because if you ask on a public forum, you are likely to get horribly wrong answers.

They just press 'engage autopilot' and the camera shows the ship(s) pass from left to right.

Unless there's Kilrathis nearby.

Quote from wheel4hummer :

What's your point? You think all the mars rovers are faked or some sort of conspiracy theory? Who cares how autopilot works in space, it just does. Someone, somewhere must know how it works. You should do some reasearch for yourself, because if you ask on a public forum, you are likely to get horribly wrong answers.

I don't think today, I think future

I think something that has not been invented yet, as I usually do

And I ask here because I'm interested to know who has imagination and who does not

Quote from (SaM) :

...... Once in free-space, there is no gravity ....

Er...I'm afraid that you will find that there IS gravity in free space...
ALL celestial objects :davosmili regardless of size have their own gravitational field, and this affects every other body in space.
It is partially through the study of the effects of gravitational fields that scientists/astronomers can deduce the existence of stars/planets/black holes etc :alien2: that would otherwise be invisible to the means currently available.


Besides...to get back on topic....in Freelancer you just hit Ctrl-A to engage autopilot

Yes there is, but in my context, it's so small it's irrelevant.

In deep space flight there are few things to note (I think)...

What kind of coordinate system(s) to use. Like GPS has the origo in centre of Earth, while flights inside the solar system would benefit from the sun centered system. In interstellar flights you could use the solar centered and then switch to Alpha Centauri (or what ever star) centered when it comes closer. Otherwise you could use galaxy (or solar) centered system to define the positions of all stars.

For nearby objects the starship centered is the best. Like when docking to space station. For that short distances radar would be good to get the distance.

For aiming towards a distant star the auto pilot could aim the light point (star). For distance measurements the same methods could be used as for stars in general and close you could just measure the angle and get the distance (because we know the star type and size quite well for nearby stars) (d=radius/tan(angle/2)). But you need to be quite close to the star and requires very accurate instruments. This is almost like the parallax method used to measure closest stars (there the earth's motion around the Sun is used as the measuring stick and thus it is better for much longer distances, but still not much more than 100ly) (note: 1 parsec=parallax second=c. 3.26ly=distance to object which has 1 arc sec movement during 6 months).

If you are dropped into an orbit around a random star there would be difficulties finding out where you are. This is because stars and constellations at the sky would look different from what they look on Earth. Having a large 3D coord database of stars and their positions in the galaxy would help, but generally we do not know exactly how far they are from Sun. The closest stars like Alpha Centauri (4.3ly) and Sirius (8.7ly) are fairly accurately known, but in more distant stars they are huge (tens of lys) inaccuracies. That's why I do not have much faith in how some programs like Celestia display the star positions.

(end of science part... now starts the science fiction part)

In one scifi book they were not allowed to have computers. Instead they harvested some 'spice' from a surface of a planet (called Arrakis) and spaceship pilots used this 'stuff' to improve their thinking and allowed them to navigate between stars w/o computers (remember what book and computer game? Does sand worms help at all? )

I remember some of that book

Good explanation of navigation, thanks.

How about electro magnetic radiation of stars, you could regonize star by that when you know that you should be near some star so you can compare that signature to data you have and find out if you really are close to proper location.

Of course charting of space will be going on at some point I believe, putting those stars more accurately on place.

Quote from Aquilifer :

In one scifi book they were not allowed to have computers. Instead they harvested some 'spice' from a surface of a planet (called Arrakis) and spaceship pilots used this 'stuff' to improve their thinking and allowed them to navigate between stars w/o computers (remember what book and computer game? Does sand worms help at all? )

Not really sure...I'll have to ask my mate Paul Atriedes if he or Duncan knows the answer...
I feel a right Herbert sometimes!!