Navicomputer calibration after a gravitic anomaly
The hardware usually survives. The almanac quietly does not, and a corrupted lane solution looks exactly like a good one until you are committed.
Ships pass through gravitic anomalies more often than the incident statistics suggest, because most passages produce no immediate symptom at all. The navicomputer keeps working. That is the problem.
What an anomaly does to stored data
A steep gravitic gradient induces state changes in dense storage. It does not usually damage the core, the interfaces or the display. It flips a small number of bits in a very large number of stored lane solutions.
A lane solution with a few flipped bits is still a syntactically valid solution. It will load, it will display, and it will plot a course that is subtly wrong in a way that a plot review will not catch — because the plot review is reading the same corrupted data.
The verification procedure
After any transit through a gradient above 5 g, before your next jump:
- Run a full almanac verification, not a spot check. On the NC-1701 this takes about forty minutes and re-verifies every stored solution against its checksum.
- Read the repair report. Self-healing storage will silently fix what it can. You want to know how much it fixed. A handful of corrected solutions is routine. Several thousand means the exposure was worse than you thought and you should verify twice.
- Cross-check one known lane by hand. Pick a route you have flown, plot it, compare to your own records. This catches the case where the corruption reached the checksums themselves.
- Check the secondary core independently. Hot standby cores are exposed to the same gradient. Two cores agreeing is not confirmation if both were corrupted the same way.
- Log the exposure. Peak gradient, duration, corrections applied. The next crew will want it.
Why spot checks are worse than nothing
A spot check verifies a sample and returns clean, which produces confidence rather than information. Corruption from a gradient is not uniformly distributed — it concentrates in whichever physical storage regions were oriented unfavourably. A sample drawn from a clean region says nothing about the affected one, and the crew now believes the almanac is verified.
On not having local storage
Some operators respond to all of this by preferring a relay-dependent navicomputer that fetches solutions on demand and therefore cannot hold corrupt ones. This trades a manageable problem for an unmanageable one: the relay is unavailable exactly where anomalies are common, which is exactly where you most need to re-plot.
Carry the almanac. Verify it after events. The procedure above has caught real corruption on customer hulls eleven times that we know of, and in at least two of those the crew had already plotted a jump.