Juno perijoves 2 and 3, October 19 and December 11, 2016 |
Juno perijoves 2 and 3, October 19 and December 11, 2016 |
Oct 26 2016, 04:44 PM
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Junior Member Group: Members Posts: 23 Joined: 13-October 13 Member No.: 7013 |
A lot has happened and it seemed like a good time to start a new post. We will be staying in 53 day orbits until the project has a full understanding of the risks that may or may not be associated with reducing the orbit period to 14 days per our previous plan.
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Dec 21 2016, 11:11 PM
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#2
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Senior Member Group: Members Posts: 1669 Joined: 5-March 05 From: Boulder, CO Member No.: 184 |
Gerald - here is the correction term for the orbital acceleration as it appears in my vintage (1970s) software. I'm unsure how easy it would be to retool this to run for Jupiter, though we could at least do some type of scale analysis on this, or augment another simulation program accordingly. The RDRD or r dot rdot term is sensitive to how elliptical the orbit is as one might expect.
! ADD PERTURBATIVE ACCELERATION DUE TO GENERAL RELATIVITY RDRD=X(I)*XD(I)+Y(I)*YD(I)+Z(I)*ZD(I) VSQ=XD(I)*XD(I)+YD(I)*YD(I)+ZD(I)*ZD(I) A=FOURM*RLCM1-VSQ*CM2 B=FOURM*RDRD*RLCM3 XDD(I)=XDD(I)*(1.D0-A)+B*XD(I) YDD(I)=YDD(I)*(1.D0-A)+B*YD(I) ZDD(I)=ZDD(I)*(1.D0-A)+B*ZD(I) The terms are defined as follows: RDRD - r dot rdot - dot product of position and velocity XYZ - position vector in AU XD,YD,ZD - velocity vector XDD,YDD,ZDD - acceleration vector FOURM - 4 times the mass of the central object RLCM1 - inverse distance between the two bodies CM2 - 1 / c squared (c = speed of light) I should try and look up the Cowell Astronomical Papers reference where I obtained this. The above just applies to calculating the GR perturbed positions. The clock changes are a different calculation. -------------------- Steve [ my home page and planetary maps page ]
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