Compasses don't work on Mars, so how do you navigate?
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Re: Compasses don't work on Mars, so how do you navigate?
#2GPS
Re: Compasses don't work on Mars, so how do you navigate?
#3GPS
We haven't put GPS satellites around Mars quite yet. I'm guessing that won't happen until it gets terraformed.
Re: Compasses don't work on Mars, so how do you navigate?
#4Re: Compasses don't work on Mars, so how do you navigate?
#5stellar inertial navigation - It means that as well as an inertial system you track the stars... which are actually visible even during daylight through an automated telecope system... although not through cloud I guess.
Pricey but so is getting to Mars
Re: Compasses don't work on Mars, so how do you navigate?
#6Earlier quoted context omitted.
We haven't put GPS satellites around Mars quite yet. I'm guessing that won't happen until it gets terraformed.
On the other hand if we are coming in from space in the first place, it might not be too terribly hard to drop a few satellites off on your way down?
Further if you're not looking for realtime direction finding and you're willing to wait a few minutes for a fix, you can get away with far fewer satellites.
Putting 6 small satellites in orbit and getting position fixes every hour would still be way better than nothing.
Re: Compasses don't work on Mars, so how do you navigate?
#7Already done? More than 40 years ago, but probably still workable:
https://en.wikipedia.org/wiki/Lunar_Roving_Vehicle#Control_a...
Re: Compasses don't work on Mars, so how do you navigate?
#8Celestial navigation plus accurate clocks. I'd think this would be especially good on a planet without clouds (as long as your planet rotates fast enough, so I guess Mercury is out). Anyone know if Mars has any polar stars?
Re: Compasses don't work on Mars, so how do you navigate?
#9Celestial navigation plus accurate clocks. I'd think this would be especially good on a planet without clouds (as long as your planet rotates fast enough, so I guess Mercury is out). Anyone know if Mars has any polar stars? https://en.wikipedia.org/wiki/Celestial_navigation
The planet doesn't have to rotate to use celestial navigation. As long as you can see the stars you are fine.
So the dark side of mercury would work fine. On the hot side as long as you are not exactly on the equator the sun acts as a fixed direction and you can use that.
> Anyone know if Mars has any polar stars?
The orbital tilt of Mars is 1.85 degrees (vs 0 for earth) and the Axial tilt is 25.19 vs 23.44 for Earth. So Polaris would be pretty close to being a polar star for Mars as well.
Re: Compasses don't work on Mars, so how do you navigate?
#10Earlier quoted context omitted.
On the other hand if we are coming in from space in the first place, it might not be too terribly hard to drop a few satellites off on your way down?
Further if you're not looking for realtime direction finding and you're willing to wait a few minutes for a fix, you can get away with far fewer satellites. Putting 6 small satellites in orbit and getting position fixes every hour would still be way better than nothing.
How would the satellites themselves maintain their proper positions relative to Mars, without ground stations to orient against?