FA-69584 / Orbital propagation / Member archive

J2 secular node and perigee drift: Perigee drift factor has the wrong sign · case 04

Critical inclination still shows perigee drift of the wrong direction.

Member previewVariant 4 · 3 implementations · 7 checks per implementation

Case contract

Input [a km, e, i deg, days]. With mu=398600.4418, Re=6378.137, J2=1.08263e-3, n=sqrt(mu/a^3), p=a(1-e^2): dRAAN/dt=-1.5 n J2 (Re/p)^2 cos i, dargp/dt=0.75 n J2 (Re/p)^2 (5cos^2 i-1). Return [RAAN drift deg, argp drift deg over the interval (rounded 4), sun-synchronous flag: |RAAN rate in deg/day - 0.9856|<0.01].

Why this case matters

Orbit determination and mission planning chain many small conversions; one wrong branch or unit silently moves a spacecraft by kilometres.

One recorded failure

Sample boundary fixture

This sample comes from the broken implementation of a controlled reproducer.

Boundary fixture	Actual	Expected	Outcome
j2 secular node and perigee drift [7000.0, 0.2, 28.5, 3]	`[-20.5825, -33.5103, false]`	`[-20.5825, 33.5103, false]`	Failed

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