Naked Science Forum
General Science => General Science => Topic started by: chris on 19/11/2010 09:15:50
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On Earth we have compasses, sat navs, maps, landmarks and even road signs (of dubious use).
But what about in space? How will the space voyagers of the future know where they are going? What's the reference point and how will they navigate?
Chris
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I always assumed triangulation from known points in the sky. We can already put together a fair 3d representation of our local area. Any three sufficiently distant known points (that are not on a single plane) will allow determination of position. If I was sitting in my tin can far above the moon - I would want many more points of reference and failsafe systems, but if push came to shove you could work out your position with observations, angles and a pad of paper.
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I always thought it would be dead reckoning until close enough to the interest object to orientate appropriately
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I tend to agree with both the above. There are plenty of known objects which are far enough away to be considered fixed reference points. And cloud isn't going to be a problem :-)
You could use dead reckoning too (also simpler without tides though you may have gravitational field to account for) but given that you should always have these references available it isn't really necessary. Plotting an optimum course would still be required.
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Haven't they invented IPS yet? (Intergalactic Positioning System)
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My suggestion, when I discussed this on the radio, was that, as others have said above, stars that are sufficiently distant so as to be considered stationary points can be used as fixed reference points; this means that space navigators would, ironically, be employing the same techniques that the early ocean explorers used to find their way around the Earth!
Chris
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Well apart from star charts, I would imagine such ships would have gyroscopic navigation, like nuclear subamarines.
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Good point - but a gyroscope can only keep you stable in one position; it can't tell you physically where you are or how far you have travelled...
Chris
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Good point - but a gyroscope can only keep you stable in one position; it can't tell you physically where you are or how far you have travelled...
Chris
Don't tell that to the guys that invented inertial navigation systems [:D]
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Yes, an inertial navigation system uses gyroscopes, accelerometers and a clock and then can dead reckon your position relative to your initial position and initial velocity vector. However, I don't really see why this would be necessary when you can always see the stars; maybe it could serve as a backup system for some peculiar region of space (such as occur in Star Trek) where the stars are not visible.
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Good point - but a gyroscope can only keep you stable in one position; it can't tell you physically where you are or how far you have travelled...
Chris
Nucelar subs can and do navigate in this way. Every few weeks they have to pop up to get gps to correct inaccuracies, but they are never miles away from where they thought they should be.
If you can detect a change in direction from stationary then you can detect changes in direction during movement. Mainly because there is no such thing as stationary - stationary with respect to what? Even a stationary boat is on the earth that is spinning, and orbiting the sun, and the gyroscopes detect this.
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On Earth we have compasses, sat navs, maps, landmarks and even road signs (of dubious use).
But what about in space? How will the space voyagers of the future know where they are going? What's the reference point and how will they navigate?
Chris
I can imagine a sort of a crows nest and the use of a Sextant, Trianglulation with referencing the Most well known Stellar points, Sun (Sol), Northern Star (Polaris), some othe well know point... maybe Earth....
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http://en.wikipedia.org/wiki/Sextant
Then there is that sign, located between here and there, a famous road, an Italian favorite, named after many, Called Una Via.