Space Agencies Editing and Proofreading Services

The flight readiness review lists a known issue with an O-ring's cold-weather performance as an open item, accepted for flight, with a one-line rationale: "acceptable based on flight history." Flight history includes several previous flights where the same component showed the same erosion pattern and nobody was hurt. The rationale does not explain why erosion that has occurred before and not caused a failure means it will not cause one this time, particularly not at a temperature colder than any previous launch. The distinction between "this has not failed yet" and "this will not fail" is exactly the distinction the rationale was supposed to make, and it does not make it.

We edit what space agencies and mission teams produce for flight readiness and risk decisions — flight readiness review documentation and risk acceptance rationales, open item and waiver dispositions, mission assurance and safety review board material, anomaly and in-flight problem reports, post-mission and post-failure investigation reports, and the dissenting or minority opinion documentation that a review process is supposed to be able to carry. Our editors work on the sentence that has to justify flying with a known, unresolved risk.

The risk acceptance rationale is what a flight readiness review is actually for, and its failure is a conclusion that restates the decision instead of justifying it. Acceptable based on flight history describes what was decided, not why it is sound. We work through these so the rationale distinguishes evidence that the failure mode is understood and bounded from evidence that it simply has not caused a loss yet, since a component behaving unpredictably within tolerances that happen not to have been exceeded is not the same as a component whose behaviour is actually characterised and predictable; so any condition present on this flight that differs from prior flights — temperature, loading, a design change — is stated explicitly and addressed, given that a rationale relying on flight history has to show the history actually applies to the conditions now present, not merely that it exists; so a dissenting engineering opinion, where one exists, is recorded and addressed on its merits rather than smoothed into a unanimous recommendation, because a review record with no visible disagreement where disagreement is known to have occurred is a record that has already failed as documentation; so the rationale states what specifically would change the acceptance decision, as a risk accepted with no stated limit is a risk accepted indefinitely; so an open item's status is tracked against what closing it actually requires, rather than carried forward flight after flight as familiar and therefore lower priority; and so post-mission reports distinguish what was learned from what merely confirmed existing belief, given that a launch that succeeds despite an accepted risk is evidence about luck as much as about the risk itself. Rationales written this way are the ones that hold up when someone reads them again after something has gone wrong.

Everything you send is treated in confidence, including technical data, review material and personnel information. We are editors rather than engineers, safety officers or mission planners, and we offer no view on risk, safety or flight readiness decisions. What we can do is make sure the reasoning is actually visible on the page.