← Technical Briefs

From Mission Concept to Certified Code

8/10/2025

Problem

GN&C programs commonly suffer from fragmented handoffs, duplicated models, and late discovery of interface/constraint conflicts. Small requirement changes ripple through navigation, guidance, control, and ops products—creating rework and schedule risk.

What We Do

Astro Aerospace executes your GN&C effort end-to-end—from early requirements through certified flight code and operational handover. We use our proprietary internal tools to maintain a single data model for interfaces, constraints, and verification artifacts across the stack.

Outcome: traceable requirements, validated design, flight-ready code, and a NASA-aligned compliance dossier.


Engagement Inputs

  • Mission objectives and success criteria
  • Vehicle configuration (sensors/actuators, buses, resource budgets)
  • Environmental regimes and operational constraints (power, thermal, antenna/FOV, rate limits)
  • Program standards and certification targets (NASA frameworks, company coding standards)

Delivery Flow (Concept → Certified Code)

01 — Discovery & Requirements

  • Capture stakeholder objectives, measurable performance targets, and operational constraints.
  • Define GN&C success metrics (e.g., pointing accuracy, propellant budget, settling time, latency).
  • Establish traceability structure linking requirements → models → tests → evidence.

Outputs: requirements set, risk register, initial test strategy.

02 — Architecture & Interfaces

  • Build the GN&C architecture with interface contracts (signals, units, timing, accuracy).
  • Allocate constraint budgets (power/thermal/FOV/rates/CPU) to subsystems.
  • Select algorithmic approaches and observability/controllability strategy.

Outputs: architecture spec, interface contracts, constraint budget table.

03 — Simulation & Design

  • Develop closed-loop simulations for key regimes and corner cases.
  • Design and tune navigation filters, guidance profiles, and control laws.
  • When a requirement changes, our toolchain flags dependent interfaces/constraints and triggers automatic re-validation in the affected campaigns.

Outputs: GN&C models, tuning pack with rationales, simulation results.

04 — Integration & Flight Code

  • Generate and/or implement C/C++ flight code aligned with project coding standards.
  • Provide scaffolds for unit tests and continuous integration.
  • Ensure determinism, resource compliance, and timing budgets are honored.

Outputs: flight-code modules, unit-test scaffolds, integration notes.

05 — Verification & Validation

  • Execute Monte-Carlo and worst-case search campaigns tied to requirements.
  • Maintain regression testpacks for changes and defect fixes.
  • Produce quantitative coverage summaries and evidence packets.

Note: Hardware-in-the-Loop (HIL) is optional via partner facilities; this brief assumes simulation-centric V&V.

Outputs: coverage and sensitivity reports, requirement pass/fail ledger, signed evidence.

06 — Certification Evidence & Ops Handover

  • Assemble a NASA-aligned compliance dossier: matrices, rationales, test evidence, and sign-offs.
  • Prepare operations materials: sequence/command templates, constraint checks, and on-call engineering support plan.

Outputs: compliance dossier, ops handbook, acceptance package.

Tooling Principles (How We Reduce Rework)

  • Single Data Model: interfaces, constraints, requirements, and verification artifacts are linked, so changes propagate deterministically.
  • Interface Contracts: strict signal/timing/units definitions prevent integration surprises.
  • Constraint Budgets: power/thermal/FOV/rate/CPU limits are tracked and re-validated when designs move.
  • Automated Re-validation: affected test campaigns re-run on change—before code merges.
  • Regression Packs: permanent guardrails built from real defects and edge cases.

Deliverables You Receive

  • GN&C Architecture Specification & Interface Contracts
  • Algorithms & Tuning Pack with rationales and operating envelopes
  • Flight Code (C/C++) with unit-test scaffolds and CI hooks
  • Verification Artifacts: Monte-Carlo campaigns, worst-case search, regression results
  • Certification Dossier: NASA-aligned matrices, evidence, and sign-offs
  • Operations Materials: sequence templates, constraint monitors, support plan

Acceptance & Exit Criteria (Typical)

  • All Level-1/Level-2 requirements verified with evidence and coverage thresholds met
  • Timing/resource budgets pass on final configuration
  • No open Cat-1 defects; Cat-2s have workarounds and are tracked
  • Compliance dossier accepted by program authority; ops handover complete

Why This Works

A unified model of requirements → interfaces → constraints → verification prevents late surprises. When something changes, the system pinpoints what must be updated and proves the change safe via targeted re-validation. That’s how we deliver faster cycles, lower rework, and certified flight code with confidence.