FA-69586 / Orbital propagation / Open access

J2 secular node and perigee drift: Days are converted to seconds with an hourly factor · case 01

Accumulated drift is 24 times too small.

Verified by executionVariant 1 · 7 checks per implementationDownload source bundle ↓JSON ↗

ROOT CAUSE

The interval uses days*3600.

VERIFIED REPAIR

Use 86400 seconds per day.

Unsuccessful approach: Using 1440 treats the factor as minutes per day.

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.

1 / The failure

Exit 1

"""Failure Map reference implementation. Python standard library only."""
import json
import math
N = 1
observations = []
def solve(x):
    a,e,i,days=x
    mu,Re,J2=398600.4418,6378.137,1.08263e-3
    n=math.sqrt(mu/a**3)
    p=a*(1-e*e)
    ci=math.cos(math.radians(i))
    fac=n*J2*(Re/p)**2
    dO=-1.5*fac*ci
    dw=0.75*fac*(5*ci*ci-1)
    t=days*3600
    sso=abs(math.degrees(dO)*86400-0.9856)<0.01
    return [round(math.degrees(dO*t),4),round(math.degrees(dw*t),4),sso]
def check(label, actual, expected):
    observations.append({"check": label, "actual": actual, "expected": expected, "passed": actual == expected})
fixtures = [[('j2 secular node and perigee drift [7078.0, 0.001, 98.19, 1]', [7078.0, 0.001, 98.19, 1], [0.986, -3.1094, True]), ('j2 secular node and perigee drift [7078.0, 0.001, 51.6, 1]', [7078.0, 0.001, 51.6, 1], [-4.2991, 3.2153, False]), ('j2 secular node and perigee drift [26560.0, 0.74, 63.4, 10]', [26560.0, 0.74, 63.4, 10], [-1.4793, 0.004, False]), ('j2 secular node and perigee drift [7000.0, 0.2, 28.5, 3]', [7000.0, 0.2, 28.5, 3], [-20.5825, 33.5103, False]), ('j2 secular node and perigee drift [6878.0, 0.0, 97.4, 2]', [6878.0, 0.0, 97.4, 2], [1.971, -7.0169, True]), ('j2 secular node and perigee drift [7500.0, 0.05, 82.0, 5]', [7500.0, 0.05, 82.0, 5], [-3.9523, -12.8241, False]), ('j2 secular node and perigee drift [12000.0, 0.3, 120.0, 7]', [12000.0, 0.3, 120.0, 7], [4.6102, 1.1525, False])], [('j2 secular node and perigee drift [7078.0, 0.001, 51.6, 1]', [7078.0, 0.001, 51.6, 1], [-4.2991, 3.2153, False]), ('j2 secular node and perigee drift [7000.0, 0.2, 28.5, 3]', [7000.0, 0.2, 28.5, 3], [-20.5825, 33.5103, False]), ('j2 secular node and perigee drift [6878.0, 0.0, 97.4, 2]', [6878.0, 0.0, 97.4, 2], [1.971, -7.0169, True]), ('j2 secular node and perigee drift [7500.0, 0.05, 82.0, 5]', [7500.0, 0.05, 82.0, 5], [-3.9523, -12.8241, False]), ('j2 secular node and perigee drift [12000.0, 0.3, 120.0, 7]', [12000.0, 0.3, 120.0, 7], [4.6102, 1.1525, False]), ('j2 secular node and perigee drift [42164.0, 0.0, 0.1, 30]', [42164.0, 0.0, 0.1, 30], [-0.4024, 0.8049, False]), ('j2 secular node and perigee drift [7078.0, 0.001, 81.81, 1]', [7078.0, 0.001, 81.81, 1], [-0.986, -3.1094, False])], [('j2 secular node and perigee drift [26560.0, 0.74, 63.4, 10]', [26560.0, 0.74, 63.4, 10], [-1.4793, 0.004, False]), ('j2 secular node and perigee drift [12000.0, 0.3, 120.0, 7]', [12000.0, 0.3, 120.0, 7], [4.6102, 1.1525, False]), ('j2 secular node and perigee drift [42164.0, 0.0, 0.1, 30]', [42164.0, 0.0, 0.1, 30], [-0.4024, 0.8049, False]), ('j2 secular node and perigee drift [7078.0, 0.001, 81.81, 1]', [7078.0, 0.001, 81.81, 1], [-0.986, -3.1094, False]), ('j2 secular node and perigee drift [8000.0, 0.1, 45.0, 0.5]', [8000.0, 0.1, 45.0, 0.5], [-1.6264, 1.7251, False]), ('j2 secular node and perigee drift [7078.0, 0.001, 98.19, 1]', [7078.0, 0.001, 98.19, 1], [0.986, -3.1094, True]), ('j2 secular node and perigee drift [7078.0, 0.001, 51.6, 1]', [7078.0, 0.001, 51.6, 1], [-4.2991, 3.2153, False])], [('j2 secular node and perigee drift [7000.0, 0.2, 28.5, 3]', [7000.0, 0.2, 28.5, 3], [-20.5825, 33.5103, False]), ('j2 secular node and perigee drift [8000.0, 0.1, 45.0, 0.5]', [8000.0, 0.1, 45.0, 0.5], [-1.6264, 1.7251, False]), ('j2 secular node and perigee drift [7078.0, 0.001, 98.19, 1]', [7078.0, 0.001, 98.19, 1], [0.986, -3.1094, True]), ('j2 secular node and perigee drift [7078.0, 0.001, 51.6, 1]', [7078.0, 0.001, 51.6, 1], [-4.2991, 3.2153, False]), ('j2 secular node and perigee drift [26560.0, 0.74, 63.4, 10]', [26560.0, 0.74, 63.4, 10], [-1.4793, 0.004, False]), ('j2 secular node and perigee drift [6878.0, 0.0, 97.4, 2]', [6878.0, 0.0, 97.4, 2], [1.971, -7.0169, True]), ('j2 secular node and perigee drift [7500.0, 0.05, 82.0, 5]', [7500.0, 0.05, 82.0, 5], [-3.9523, -12.8241, False])], [('j2 secular node and perigee drift [6878.0, 0.0, 97.4, 2]', [6878.0, 0.0, 97.4, 2], [1.971, -7.0169, True]), ('j2 secular node and perigee drift [26560.0, 0.74, 63.4, 10]', [26560.0, 0.74, 63.4, 10], [-1.4793, 0.004, False]), ('j2 secular node and perigee drift [7000.0, 0.2, 28.5, 3]', [7000.0, 0.2, 28.5, 3], [-20.5825, 33.5103, False]), ('j2 secular node and perigee drift [7500.0, 0.05, 82.0, 5]', [7500.0, 0.05, 82.0, 5], [-3.9523, -12.8241, False]), ('j2 secular node and perigee drift [12000.0, 0.3, 120.0, 7]', [12000.0, 0.3, 120.0, 7], [4.6102, 1.1525, False]), ('j2 secular node and perigee drift [42164.0, 0.0, 0.1, 30]', [42164.0, 0.0, 0.1, 30], [-0.4024, 0.8049, False]), ('j2 secular node and perigee drift [7078.0, 0.001, 81.81, 1]', [7078.0, 0.001, 81.81, 1], [-0.986, -3.1094, False])]]
for label, args, expected in fixtures[N-1]:
    check(label, solve(args), expected)
print(json.dumps({"observations": observations, "passed": all(x["passed"] for x in observations)}, ensure_ascii=False))
raise SystemExit(0 if all(x["passed"] for x in observations) else 1)

Boundary fixture	Actual	Expected	Outcome
j2 secular node and perigee drift [7078.0, 0.001, 98.19, 1]	`[0.0411, -0.1296, True]`	`[0.986, -3.1094, True]`	Failed
j2 secular node and perigee drift [7078.0, 0.001, 51.6, 1]	`[-0.1791, 0.134, False]`	`[-4.2991, 3.2153, False]`	Failed
j2 secular node and perigee drift [26560.0, 0.74, 63.4, 10]	`[-0.0616, 0.0002, False]`	`[-1.4793, 0.004, False]`	Failed
j2 secular node and perigee drift [7000.0, 0.2, 28.5, 3]	`[-0.8576, 1.3963, False]`	`[-20.5825, 33.5103, False]`	Failed
j2 secular node and perigee drift [6878.0, 0.0, 97.4, 2]	`[0.0821, -0.2924, True]`	`[1.971, -7.0169, True]`	Failed
j2 secular node and perigee drift [7500.0, 0.05, 82.0, 5]	`[-0.1647, -0.5343, False]`	`[-3.9523, -12.8241, False]`	Failed
j2 secular node and perigee drift [12000.0, 0.3, 120.0, 7]	`[0.1921, 0.048, False]`	`[4.6102, 1.1525, False]`	Failed

SHA-256 / d9e45fb2e78f56efe6a6d5ae38d4e37040dfdebfa57515fe8f7dbd1d8c90b7e7

2 / The unsuccessful fix

Exit 1

"""Failure Map reference implementation. Python standard library only."""
import json
import math
N = 1
observations = []
def solve(x):
    a,e,i,days=x
    mu,Re,J2=398600.4418,6378.137,1.08263e-3
    n=math.sqrt(mu/a**3)
    p=a*(1-e*e)
    ci=math.cos(math.radians(i))
    fac=n*J2*(Re/p)**2
    dO=-1.5*fac*ci
    dw=0.75*fac*(5*ci*ci-1)
    t=days*1440
    sso=abs(math.degrees(dO)*86400-0.9856)<0.01
    return [round(math.degrees(dO*t),4),round(math.degrees(dw*t),4),sso]
def check(label, actual, expected):
    observations.append({"check": label, "actual": actual, "expected": expected, "passed": actual == expected})
fixtures = [[('j2 secular node and perigee drift [7078.0, 0.001, 98.19, 1]', [7078.0, 0.001, 98.19, 1], [0.986, -3.1094, True]), ('j2 secular node and perigee drift [7078.0, 0.001, 51.6, 1]', [7078.0, 0.001, 51.6, 1], [-4.2991, 3.2153, False]), ('j2 secular node and perigee drift [26560.0, 0.74, 63.4, 10]', [26560.0, 0.74, 63.4, 10], [-1.4793, 0.004, False]), ('j2 secular node and perigee drift [7000.0, 0.2, 28.5, 3]', [7000.0, 0.2, 28.5, 3], [-20.5825, 33.5103, False]), ('j2 secular node and perigee drift [6878.0, 0.0, 97.4, 2]', [6878.0, 0.0, 97.4, 2], [1.971, -7.0169, True]), ('j2 secular node and perigee drift [7500.0, 0.05, 82.0, 5]', [7500.0, 0.05, 82.0, 5], [-3.9523, -12.8241, False]), ('j2 secular node and perigee drift [12000.0, 0.3, 120.0, 7]', [12000.0, 0.3, 120.0, 7], [4.6102, 1.1525, False])], [('j2 secular node and perigee drift [7078.0, 0.001, 51.6, 1]', [7078.0, 0.001, 51.6, 1], [-4.2991, 3.2153, False]), ('j2 secular node and perigee drift [7000.0, 0.2, 28.5, 3]', [7000.0, 0.2, 28.5, 3], [-20.5825, 33.5103, False]), ('j2 secular node and perigee drift [6878.0, 0.0, 97.4, 2]', [6878.0, 0.0, 97.4, 2], [1.971, -7.0169, True]), ('j2 secular node and perigee drift [7500.0, 0.05, 82.0, 5]', [7500.0, 0.05, 82.0, 5], [-3.9523, -12.8241, False]), ('j2 secular node and perigee drift [12000.0, 0.3, 120.0, 7]', [12000.0, 0.3, 120.0, 7], [4.6102, 1.1525, False]), ('j2 secular node and perigee drift [42164.0, 0.0, 0.1, 30]', [42164.0, 0.0, 0.1, 30], [-0.4024, 0.8049, False]), ('j2 secular node and perigee drift [7078.0, 0.001, 81.81, 1]', [7078.0, 0.001, 81.81, 1], [-0.986, -3.1094, False])], [('j2 secular node and perigee drift [26560.0, 0.74, 63.4, 10]', [26560.0, 0.74, 63.4, 10], [-1.4793, 0.004, False]), ('j2 secular node and perigee drift [12000.0, 0.3, 120.0, 7]', [12000.0, 0.3, 120.0, 7], [4.6102, 1.1525, False]), ('j2 secular node and perigee drift [42164.0, 0.0, 0.1, 30]', [42164.0, 0.0, 0.1, 30], [-0.4024, 0.8049, False]), ('j2 secular node and perigee drift [7078.0, 0.001, 81.81, 1]', [7078.0, 0.001, 81.81, 1], [-0.986, -3.1094, False]), ('j2 secular node and perigee drift [8000.0, 0.1, 45.0, 0.5]', [8000.0, 0.1, 45.0, 0.5], [-1.6264, 1.7251, False]), ('j2 secular node and perigee drift [7078.0, 0.001, 98.19, 1]', [7078.0, 0.001, 98.19, 1], [0.986, -3.1094, True]), ('j2 secular node and perigee drift [7078.0, 0.001, 51.6, 1]', [7078.0, 0.001, 51.6, 1], [-4.2991, 3.2153, False])], [('j2 secular node and perigee drift [7000.0, 0.2, 28.5, 3]', [7000.0, 0.2, 28.5, 3], [-20.5825, 33.5103, False]), ('j2 secular node and perigee drift [8000.0, 0.1, 45.0, 0.5]', [8000.0, 0.1, 45.0, 0.5], [-1.6264, 1.7251, False]), ('j2 secular node and perigee drift [7078.0, 0.001, 98.19, 1]', [7078.0, 0.001, 98.19, 1], [0.986, -3.1094, True]), ('j2 secular node and perigee drift [7078.0, 0.001, 51.6, 1]', [7078.0, 0.001, 51.6, 1], [-4.2991, 3.2153, False]), ('j2 secular node and perigee drift [26560.0, 0.74, 63.4, 10]', [26560.0, 0.74, 63.4, 10], [-1.4793, 0.004, False]), ('j2 secular node and perigee drift [6878.0, 0.0, 97.4, 2]', [6878.0, 0.0, 97.4, 2], [1.971, -7.0169, True]), ('j2 secular node and perigee drift [7500.0, 0.05, 82.0, 5]', [7500.0, 0.05, 82.0, 5], [-3.9523, -12.8241, False])], [('j2 secular node and perigee drift [6878.0, 0.0, 97.4, 2]', [6878.0, 0.0, 97.4, 2], [1.971, -7.0169, True]), ('j2 secular node and perigee drift [26560.0, 0.74, 63.4, 10]', [26560.0, 0.74, 63.4, 10], [-1.4793, 0.004, False]), ('j2 secular node and perigee drift [7000.0, 0.2, 28.5, 3]', [7000.0, 0.2, 28.5, 3], [-20.5825, 33.5103, False]), ('j2 secular node and perigee drift [7500.0, 0.05, 82.0, 5]', [7500.0, 0.05, 82.0, 5], [-3.9523, -12.8241, False]), ('j2 secular node and perigee drift [12000.0, 0.3, 120.0, 7]', [12000.0, 0.3, 120.0, 7], [4.6102, 1.1525, False]), ('j2 secular node and perigee drift [42164.0, 0.0, 0.1, 30]', [42164.0, 0.0, 0.1, 30], [-0.4024, 0.8049, False]), ('j2 secular node and perigee drift [7078.0, 0.001, 81.81, 1]', [7078.0, 0.001, 81.81, 1], [-0.986, -3.1094, False])]]
for label, args, expected in fixtures[N-1]:
    check(label, solve(args), expected)
print(json.dumps({"observations": observations, "passed": all(x["passed"] for x in observations)}, ensure_ascii=False))
raise SystemExit(0 if all(x["passed"] for x in observations) else 1)

Boundary fixture	Actual	Expected	Outcome
j2 secular node and perigee drift [7078.0, 0.001, 98.19, 1]	`[0.0164, -0.0518, True]`	`[0.986, -3.1094, True]`	Failed
j2 secular node and perigee drift [7078.0, 0.001, 51.6, 1]	`[-0.0717, 0.0536, False]`	`[-4.2991, 3.2153, False]`	Failed
j2 secular node and perigee drift [26560.0, 0.74, 63.4, 10]	`[-0.0247, 0.0001, False]`	`[-1.4793, 0.004, False]`	Failed
j2 secular node and perigee drift [7000.0, 0.2, 28.5, 3]	`[-0.343, 0.5585, False]`	`[-20.5825, 33.5103, False]`	Failed
j2 secular node and perigee drift [6878.0, 0.0, 97.4, 2]	`[0.0328, -0.1169, True]`	`[1.971, -7.0169, True]`	Failed
j2 secular node and perigee drift [7500.0, 0.05, 82.0, 5]	`[-0.0659, -0.2137, False]`	`[-3.9523, -12.8241, False]`	Failed
j2 secular node and perigee drift [12000.0, 0.3, 120.0, 7]	`[0.0768, 0.0192, False]`	`[4.6102, 1.1525, False]`	Failed

SHA-256 / d44926dedc0f7e0e6a5f31fe614a2a76fdad5451f422712f7972d81ac4fd8ece

3 / The verified repair

Exit 0

"""Failure Map reference implementation. Python standard library only."""
import json
import math
N = 1
observations = []
def solve(x):
    a,e,i,days=x
    mu,Re,J2=398600.4418,6378.137,1.08263e-3
    n=math.sqrt(mu/a**3)
    p=a*(1-e*e)
    ci=math.cos(math.radians(i))
    fac=n*J2*(Re/p)**2
    dO=-1.5*fac*ci
    dw=0.75*fac*(5*ci*ci-1)
    t=days*86400
    sso=abs(math.degrees(dO)*86400-0.9856)<0.01
    return [round(math.degrees(dO*t),4),round(math.degrees(dw*t),4),sso]
def check(label, actual, expected):
    observations.append({"check": label, "actual": actual, "expected": expected, "passed": actual == expected})
fixtures = [[('j2 secular node and perigee drift [7078.0, 0.001, 98.19, 1]', [7078.0, 0.001, 98.19, 1], [0.986, -3.1094, True]), ('j2 secular node and perigee drift [7078.0, 0.001, 51.6, 1]', [7078.0, 0.001, 51.6, 1], [-4.2991, 3.2153, False]), ('j2 secular node and perigee drift [26560.0, 0.74, 63.4, 10]', [26560.0, 0.74, 63.4, 10], [-1.4793, 0.004, False]), ('j2 secular node and perigee drift [7000.0, 0.2, 28.5, 3]', [7000.0, 0.2, 28.5, 3], [-20.5825, 33.5103, False]), ('j2 secular node and perigee drift [6878.0, 0.0, 97.4, 2]', [6878.0, 0.0, 97.4, 2], [1.971, -7.0169, True]), ('j2 secular node and perigee drift [7500.0, 0.05, 82.0, 5]', [7500.0, 0.05, 82.0, 5], [-3.9523, -12.8241, False]), ('j2 secular node and perigee drift [12000.0, 0.3, 120.0, 7]', [12000.0, 0.3, 120.0, 7], [4.6102, 1.1525, False])], [('j2 secular node and perigee drift [7078.0, 0.001, 51.6, 1]', [7078.0, 0.001, 51.6, 1], [-4.2991, 3.2153, False]), ('j2 secular node and perigee drift [7000.0, 0.2, 28.5, 3]', [7000.0, 0.2, 28.5, 3], [-20.5825, 33.5103, False]), ('j2 secular node and perigee drift [6878.0, 0.0, 97.4, 2]', [6878.0, 0.0, 97.4, 2], [1.971, -7.0169, True]), ('j2 secular node and perigee drift [7500.0, 0.05, 82.0, 5]', [7500.0, 0.05, 82.0, 5], [-3.9523, -12.8241, False]), ('j2 secular node and perigee drift [12000.0, 0.3, 120.0, 7]', [12000.0, 0.3, 120.0, 7], [4.6102, 1.1525, False]), ('j2 secular node and perigee drift [42164.0, 0.0, 0.1, 30]', [42164.0, 0.0, 0.1, 30], [-0.4024, 0.8049, False]), ('j2 secular node and perigee drift [7078.0, 0.001, 81.81, 1]', [7078.0, 0.001, 81.81, 1], [-0.986, -3.1094, False])], [('j2 secular node and perigee drift [26560.0, 0.74, 63.4, 10]', [26560.0, 0.74, 63.4, 10], [-1.4793, 0.004, False]), ('j2 secular node and perigee drift [12000.0, 0.3, 120.0, 7]', [12000.0, 0.3, 120.0, 7], [4.6102, 1.1525, False]), ('j2 secular node and perigee drift [42164.0, 0.0, 0.1, 30]', [42164.0, 0.0, 0.1, 30], [-0.4024, 0.8049, False]), ('j2 secular node and perigee drift [7078.0, 0.001, 81.81, 1]', [7078.0, 0.001, 81.81, 1], [-0.986, -3.1094, False]), ('j2 secular node and perigee drift [8000.0, 0.1, 45.0, 0.5]', [8000.0, 0.1, 45.0, 0.5], [-1.6264, 1.7251, False]), ('j2 secular node and perigee drift [7078.0, 0.001, 98.19, 1]', [7078.0, 0.001, 98.19, 1], [0.986, -3.1094, True]), ('j2 secular node and perigee drift [7078.0, 0.001, 51.6, 1]', [7078.0, 0.001, 51.6, 1], [-4.2991, 3.2153, False])], [('j2 secular node and perigee drift [7000.0, 0.2, 28.5, 3]', [7000.0, 0.2, 28.5, 3], [-20.5825, 33.5103, False]), ('j2 secular node and perigee drift [8000.0, 0.1, 45.0, 0.5]', [8000.0, 0.1, 45.0, 0.5], [-1.6264, 1.7251, False]), ('j2 secular node and perigee drift [7078.0, 0.001, 98.19, 1]', [7078.0, 0.001, 98.19, 1], [0.986, -3.1094, True]), ('j2 secular node and perigee drift [7078.0, 0.001, 51.6, 1]', [7078.0, 0.001, 51.6, 1], [-4.2991, 3.2153, False]), ('j2 secular node and perigee drift [26560.0, 0.74, 63.4, 10]', [26560.0, 0.74, 63.4, 10], [-1.4793, 0.004, False]), ('j2 secular node and perigee drift [6878.0, 0.0, 97.4, 2]', [6878.0, 0.0, 97.4, 2], [1.971, -7.0169, True]), ('j2 secular node and perigee drift [7500.0, 0.05, 82.0, 5]', [7500.0, 0.05, 82.0, 5], [-3.9523, -12.8241, False])], [('j2 secular node and perigee drift [6878.0, 0.0, 97.4, 2]', [6878.0, 0.0, 97.4, 2], [1.971, -7.0169, True]), ('j2 secular node and perigee drift [26560.0, 0.74, 63.4, 10]', [26560.0, 0.74, 63.4, 10], [-1.4793, 0.004, False]), ('j2 secular node and perigee drift [7000.0, 0.2, 28.5, 3]', [7000.0, 0.2, 28.5, 3], [-20.5825, 33.5103, False]), ('j2 secular node and perigee drift [7500.0, 0.05, 82.0, 5]', [7500.0, 0.05, 82.0, 5], [-3.9523, -12.8241, False]), ('j2 secular node and perigee drift [12000.0, 0.3, 120.0, 7]', [12000.0, 0.3, 120.0, 7], [4.6102, 1.1525, False]), ('j2 secular node and perigee drift [42164.0, 0.0, 0.1, 30]', [42164.0, 0.0, 0.1, 30], [-0.4024, 0.8049, False]), ('j2 secular node and perigee drift [7078.0, 0.001, 81.81, 1]', [7078.0, 0.001, 81.81, 1], [-0.986, -3.1094, False])]]
for label, args, expected in fixtures[N-1]:
    check(label, solve(args), expected)
print(json.dumps({"observations": observations, "passed": all(x["passed"] for x in observations)}, ensure_ascii=False))
raise SystemExit(0 if all(x["passed"] for x in observations) else 1)

Boundary fixture	Actual	Expected	Outcome
j2 secular node and perigee drift [7078.0, 0.001, 98.19, 1]	`[0.986, -3.1094, True]`	`[0.986, -3.1094, True]`	Passed
j2 secular node and perigee drift [7078.0, 0.001, 51.6, 1]	`[-4.2991, 3.2153, False]`	`[-4.2991, 3.2153, False]`	Passed
j2 secular node and perigee drift [26560.0, 0.74, 63.4, 10]	`[-1.4793, 0.004, False]`	`[-1.4793, 0.004, False]`	Passed
j2 secular node and perigee drift [7000.0, 0.2, 28.5, 3]	`[-20.5825, 33.5103, False]`	`[-20.5825, 33.5103, False]`	Passed
j2 secular node and perigee drift [6878.0, 0.0, 97.4, 2]	`[1.971, -7.0169, True]`	`[1.971, -7.0169, True]`	Passed
j2 secular node and perigee drift [7500.0, 0.05, 82.0, 5]	`[-3.9523, -12.8241, False]`	`[-3.9523, -12.8241, False]`	Passed
j2 secular node and perigee drift [12000.0, 0.3, 120.0, 7]	`[4.6102, 1.1525, False]`	`[4.6102, 1.1525, False]`	Passed

SHA-256 / 70cb4fafeeaa1e398812b40098fdc59bf5b873a8df509da8041d5c793930ef3a

Verification & scope

A deterministic toy two-body model with stipulated constants and conventions; not flight dynamics software or a validated SGP4 implementation. This reproducer isolates one failure mechanism. Results cover the supplied fixtures. Variants within a family share a test contract and should remain grouped when constructing evaluation splits. Related mechanisms with a shared evaluation_group must also remain together; these controlled models are not independent production incidents.

Observations recorded using Python 3.12.14 at 2026-09-29T14:48:12.758512+00:00.

Case digest / b18a019aa9d56bc14a0dc30c0d06c781b876a8192ac0f9bdc2dc86cd8899346c