Notes on integration, testing, and remote ops in aerospace.

Integration testing is the worst place to find an integration bug

By integration, the bug is already expensive. How to push interface defects left — into modeling and SIL — before hardware shows up.

Dan Zaidenband·3 min read

Integration & Testing

Integration testing is the worst place to find an integration bug

By integration, the bug is already expensive. How to push interface defects left — into modeling and SIL — before hardware shows up.

Dan Zaidenband·3 min read

Start Testing Before Hardware: A Practical SIL Plan for Integration Teams

A step-by-step SIL plan you can run before the first board arrives — what to stub, what to model, and which interfaces to lock down first.

Dan Zaidenband·5 min read

The 5 Types of ICD Ambiguity That Create Late Defects (and How to Catch Them Early)

The five recurring ICD ambiguity patterns that surface as integration defects — with concrete examples and how to flag each one at review time.

Dan Zaidenband·5 min read

Integration & Testing

How to build integration tests that catch real bugs before hardware shows up.

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Integration & Testing

The Box Was Qualified Against a Spacecraft That Never Flew

Every ICD lists what the component must do. What the spacecraft owes the component is never written down, and never verified.

Dan Zaidenband·8 min read

Integration & Testing

Simulation Is the Only Rehearsal a One-Shot Interface Gets

Separation and deployment interfaces execute once. Qualification tests the mechanism; only simulation ever tests the interface.

Dan Zaidenband·6 min read

Integration & Testing

Your Simulator Only Fails the Way You Told It To

excerpt: A green simulation only proves you survived the failures you imagined. Someone has to be paid to invent the one that ends the mission.

Dan Zaidenband·7 min read

Integration & Testing

The Box Was Qualified Against a Spacecraft That Never Flew

Every ICD lists what the component must do. What the spacecraft owes the component is never written down, and never verified.

Dan Zaidenband·8 min read

Integration & Testing

Simulation Is the Only Rehearsal a One-Shot Interface Gets

Separation and deployment interfaces execute once. Qualification tests the mechanism; only simulation ever tests the interface.

Dan Zaidenband·6 min read

Interface Control (ICDs)

Authoring, reviewing, and generating ICDs that don't drift.

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Integration & Testing

The ICD Stopped Being True When It Became a Deliverable

ICDs don't go stale from carelessness. They go stale because changing one is a contract action, so the truth moves somewhere cheaper.

Dan Zaidenband·6 min read

Integration & Testing

Everything Generated From One File Agrees. That Proves Nothing.

Generate the ICD, the parsers and the simulator from one file and they can never disagree. Hubble shows what that costs.

Dan Zaidenband·4 min read

Integration & Testing

Nothing in the ICD Says Which Message Is Legal Now

An ICD lists every message that can cross an interface. It never says which are legal right now. SOHO shows the cost.

Dan Zaidenband·7 min read

Lessons from Missions

Post-mortems and case studies from the missions that shipped — and the ones that didn't.

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Integration & Testing

Changing a Shared Interface Without Breaking Downstream

Putting the interface in one schema is the easy half. Changing it mid-program without breaking the vendor downstream is the hard half.

Dan Zaidenband·6 min read

Integration & Testing

Schiaparelli's tests passed. The mission failed anyway

ESA's lander hit Mars at 300 km/h with green test reports behind it. A look at how passing tests can still miss the failure mode that matters.

Dan Zaidenband·4 min read

Industry Perspectives

How the space industry actually works — and where it's broken.

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Integration & Testing

Defense Made Open Interfaces the Law. Space Made Them Optional.

Defense made open interfaces federal law in 2019. Space still treats them as optional, and pays for it at integration.

Dan Zaidenband·7 min read

Integration & Testing

"We tested it" isn't an answer at CDR

At Critical Design Review, "we ran the tests" doesn't prove integration readiness. Here's what reviewers should ask instead — and what teams should bring.

Dan Zaidenband·3 min read

Integration & Testing

What space vendors should ship instead of source code

Source code drops are the wrong deliverable. What primes actually need from suppliers: executable interface models, conformance tests, and traceable behavior.

Dan Zaidenband·4 min read

Integration & Testing

Defense Made Open Interfaces the Law. Space Made Them Optional.

Defense made open interfaces federal law in 2019. Space still treats them as optional, and pays for it at integration.

Dan Zaidenband·7 min read

Integration & Testing

"We tested it" isn't an answer at CDR

At Critical Design Review, "we ran the tests" doesn't prove integration readiness. Here's what reviewers should ask instead — and what teams should bring.

Dan Zaidenband·3 min read