FA-69712 / Orbital propagation / Member archive

Elliptic time of flight between anomalies: Arcs crossing periapsis get negative durations · case 02

Flights through periapsis report negative time.

Member previewVariant 2 · 3 implementations · 7 checks per implementation

Case contract

Input [a, e, nu1, nu2, mu] (degrees). Convert each true anomaly to eccentric anomaly with the half-angle atan2 form and to mean anomaly in [0,2pi); flight always proceeds forward, so dM=(M2-M1) mod 2pi. Return dM/n seconds rounded to 3 with n=sqrt(mu/a^3).

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
elliptic time of flight between anomalies [1.0, 0.3, 300.0, 60.0, 1.0]	`-5.111`	`1.172`	Failed

MEMBER ARCHIVE

The complete case is available to members.

This record includes three runnable implementations, regression fixtures, execution results, and source hashes.

Member access is invitation-based. Sign in with your invited account to inspect the sources.