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Spacecraft navigation and celestial equator
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Topic: Spacecraft navigation and celestial equator (Read 1275 times)
Apollo-phill
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Posts: 650
UK
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Spacecraft navigation and celestial equator
«
on:
02/16/2012 02:44 pm »
I was reading a book about star names last night ( I know very quirky English Victorian traits ! ) and it was saying that 4000 years ago the celestial equator was 12 degrees below where it is currently . For instance,nowadays the celestial equator passes close to the star sometimes called Mintaka in the 'belt' of constellation Orion but was 12 degrees lower down 4000 years ago.
This got me thinking and couldn't find answer anywhere.
Do planetary probe planners and trajectory engineers have to take into account - for long duration missions like,say,Voyager or New Horizons - the minute change in the 'positional values' of the celestial equator over the course,of say, 5 or 10 years ?
I would not have thought it was too 'important' for inner planetary probes like MSL, Lunar Prospector and so on ?
Couldn't find any references in guidance books I have.
If they do have to use a value anyone any idea what value they use?
A-P
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Apollo-phill
Full Member
Posts: 650
UK
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Re: Spacecraft navigation and celestial equator
«
Reply #1 on:
02/16/2012 08:41 pm »
OK Forget question.
I have discovered the answer
A-P
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grakenverb
Full Member
Posts: 434
New York
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Re: Spacecraft navigation and celestial equator
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Reply #2 on:
02/17/2012 03:08 am »
Well, you have to share it with the rest of us now
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Proponent
Senior Member
Posts: 7277
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Re: Spacecraft navigation and celestial equator
«
Reply #3 on:
02/17/2012 03:48 am »
Precession
of the earth's axis of rotation, on a 26,000-year cycle.
«
Last Edit: 02/17/2012 03:50 am by Proponent
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kevin-rf
Elite Veteran
Senior Member
Posts: 8823
Overlooking the path Mary's little Lamb took..
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Re: Spacecraft navigation and celestial equator
«
Reply #4 on:
02/17/2012 02:11 pm »
So once you leave earth, you have a completely different coordinate system.
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