FA-69779 / Orbital propagation / Member archive

Radial in-track cross-track projection: In-track axis points backwards · case 04

Deputies ahead of the chief are reported behind it.

Member previewVariant 4 · 3 implementations · 7 checks per implementation

Case contract

Input [rc, vc, rd]: chief position and velocity and deputy position. R=rc/|rc|, C=(rc x vc)/|rc x vc|, I=C x R. Return the deputy offset rd-rc projected onto [R, I, C], rounded to 6.

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
radial in-track cross-track projection [[5000.0, 5000.0, 1000.0], [-5.0, 5.0, 1.0], [5003.0, 4998.0, 1002.0]]	`[0.980196, 3.240487, 2.353394]`	`[0.980196, -3.240487, 2.353394]`	Failed

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