Streak candidates on pre-Sputnik Hamburg plates and a test of orbital recurrence

Two narrow features on Hamburg Lippert astrograph plates exposed on 13 and 14 August 1953 are examined using public APPLAUSE DR4 scans. Each feature persists in two scans made with the plate rotated, establishing repeatability on the same physical negative without establishing an optical origin or the date of formation. The initially selected segment on LA08021 spans approximately 143 arcsec, with median transverse Gaussian-core widths of 4.73 and 4.55 arcsec in the two scans. A second feature on LA08025 lies about 8.8 arcmin away. Its direction varies from 86.6 to 92.0 degrees across native-pixel fitting choices, weakening an initially close directional agreement. Initially circular Earth-orbit constructions with the J2 perturbation can connect the selected points when both event times are fitted within the exposure windows. Twenty-two illustrative connections were retained; fifteen cross an independent plate, LA08017, during its exposure on 12 August. Trajectories and the extraction region were recorded before receipt of the test pixels. No convincing third trail was recovered from 86.1 million native pixels. Injection recovery was 29/60, 32/60 and 53/60 at three scan-contrast levels, limiting exclusion power. A targeted simultaneous Vatican comparison also supplied no corroboration for the selected geosynchronous geometry. The result is an unresolved candidate pair and a reproducible negative corroboration test, with no established orbital recurrence or artificial object. This is an exploratory research preprint and has not been peer reviewed. The companion research supplement contains the analysed native image crops and third-plate stripe, metadata, analysis code, recorded predictions, numerical results, manuscript source, checksums, and reproduction instructions.