FA-69435 / Orbital propagation / Member archive

Two-line element set line 2: Line number column is not checked · case 05

A line from another record type is decoded as orbital elements.

Member previewVariant 5 · 3 implementations · 7 checks per implementation

Case contract

Input one TLE line-2 string. It must be exactly 69 characters and start with "2", else None. Fields by 1-based columns: inclination 9-16, RAAN 18-25, eccentricity 27-33 with an implied leading decimal point, argument of perigee 35-42, mean anomaly 44-51, mean motion 53-63, revolution number 64-68, checksum 69 (sum of digits in columns 1-68, "-" counts 1, mod 10). Return [inc, raan, ecc, argp, M, n, rev, checksum_ok].

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
two-line element set line 2 "1 11111 0.0543 359.9999 0000050 0.0000 180.0000 1.00271798 12"	`[0.0543, 359.9999, 5e-06, 0.0, 180.0, 1.00271798, 1, false]`	`null`	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.