Dream Chaser Electric Braking System

Software Developer · 2022 · 3 years · 12 people · 1 min read

Developed safety-critical bare-metal C firmware for NASA's Dream Chaser Space Shuttle, achieving 95% code coverage and DO-178C certification

Overview

Senior team member developing electric braking system firmware for NASA's Dream Chaser Space Shuttle program. Delivered safety-critical software with high reliability for space missions

Problem

NASA required DO-178C Level C certification for all flight software. The electric braking system was safety-critical and needed rigorous testing and documentation

Constraints

  • DO-178C aerospace software standards
  • 95% code coverage requirement
  • TI ARM TMS570 safety microcontroller
  • Zero defects tolerance for space missions

Approach

Developed bare-metal C firmware meeting DO-178C standards. Achieved 95% code coverage using VectorCAST unit testing framework. Created test firmware from ground up to validate hardware during development

Key Decisions

Use bare-metal C on TI TMS570

Reasoning:

No RTOS overhead, deterministic timing critical for safety systems, proven in aerospace applications

Alternatives considered:
  • RTOS - Additional certification complexity
  • Linux - Not suitable for safety-critical

VectorCAST for unit testing

Reasoning:

Industry standard for DO-178C testing, automates code coverage analysis

Tech Stack

  • C (bare-metal)
  • TI ARM TMS570
  • VectorCAST
  • DO-178C
  • MISRA C
  • Git

Result & Impact

  • 95%
    Code Coverage
  • DO-178C Level C
    Certification Level
  • Zero flight software defects
    Defect Rate
  • Dream Chaser Space Shuttle
    NASA Program

Delivered safety-critical flight software that passed NASA review on first submission. System now flying on Dream Chaser cargo missions

Learnings

  • Bare-metal C provides deterministic timing for safety systems
  • VectorCAST automates DO-178C compliance
  • Early test firmware development speeds up hardware bring-up