The Ariane5 launcher accident
Case studies
Insulin pump
Internet worm
Ariane 5
Airbus FCS
London Ambulance
SE 8 Web


In June 1996, the new Ariane 5 rocket was launched on its maiden flight. It carried a payload of scientific satellites. Ariane 5 was commercially very significant for the European Space Agency as it could carry a much heavier payload than the Ariane 4 series of launchers. Thirty seven seconds into the flight, software in the inertial navigation system, whose software was reused from Ariane 4, shut down causing incorrect signals to be sent to the engines. These swivelled in such a way that uncontrollable stresses were placed on the rocket and it started to break up. Ground controllers initiated self-destruct and the rocket and payload was destroyed.

Use in teaching

This case study illustrates issues with requirements specification, multi-organisational working, critical systems validation and some of the problems of software reuse. The example illustrates that good software engineering practice (reuse, don't introduce changes unless necessary) can have problems. It also shows the organisational complexity of systems development and how organisational issues can lead to systems failure.I have used it in conjunction with lectures on critical systems validation.

Related chapters

Chapter 7: Requirements engineering processes
Chapter 9: Critical systems specification
Chapter 24: Critical systems validation

Supporting documents

Overview of the Ariane 5 failure

My Powerpoint presentation giving an overview of the causes of the system software failure. Download PDF from here.

Enquiry report

The failure of the rocket led to a public enquiry. This is the text of its published report.

Analysis and discussion

An analysis and discussion of the findings of the report.