P.E.R.C. 170E9A is 2 light-years out from its next target system when the stars change.

Radio data jumps, suddenly. The stellar localization system that keeps track of P.E.R.C.'s position relative to the nearby stars experiences a spike of observed-improbability.

Location Tracking: Lost position lock. Possible cosmic ray damage. Running self-check ...

Cosmic rays flipping bits in memory does sometimes happen out here, where P.E.R.C. sails unsheltered by a planetary atmosphere or terrestrial magnetosphere. The hydrogen scoop has a secondary purpose of helping redirect some of them, but occasionally a cosmic ray comes in too hot to be caught by the tenebrious magnetic fields that keep P.E.R.C.'s ramjet running.

This is why P.E.R.C. is built with 3-of-5 synchronized CPUs, shielded NVRAM, and backups of its core operating system on magnetic tape.

Location Tracking: Self-check reports no errors.

Location Tracking: No position lock, recovery failed, unknown course. Waking guidance module ...