A bug and a crash, failure of a decade work

1. European Space
Agency’s
Ariane 5
IN 2200
145049J

2. Ariane 5 - A decade hard work
failure by a bug
Ariane 5 rocket is the huge investment worthing 7 billion dollars designed by European
Space Agency (ESA) after the success of Ariane 4 ,that took a decade and ended as a failed
mission by a careless data type casting. The first launch took place on Tuesday 4th June 1996 .
It was a powerful technology of the time which was capable of transporting a pair of
satellites. The main focus was to create a high capacity launch vehicle that is reliable which
may contribute to the International Space Station and intended to provide devastating
supremacy in the commercial space business for European Union.

3. Design of Ariane 5
Flight control system of Ariane 5
Inertial Reference System (SRI)
On Board Computer (OBC)
Flight program

4. Introduction to launch failure
 Approximately 39 seconds after successful lift-off,
the Ariane 5 lost control. Incorrect control signals
were sent to engine and these swivelled so that
unsustainable stresses were imposed on the
rocket which resulted in the breaking up of the
vehicle.
 This was a result of careless typecasting .

5. The ESA nominated an investigation board to
investigate the launch failure that was requested to
determine the following
 to determine the causes of the launch failure
 to investigate whether the qualification tests and acceptance tests were
appropriate in relation to the problem encountered
 to recommend corrective action to remove the causes of the anomaly and
other possible weaknesses of the systems found to be at fault.

6. Software Failure
 The shutdown of the rocket took place when the guidance system's own
computer tried to convert one piece of data -- the sideways velocity of the
rocket -- from a 64-bit format to a 16-bit format.
 This particular variable was not subjected to range checks , though
conversions of other variables in the code were protected. The exception
ceased the reference platforms, resulting in the demolition of the flight.
 Terminated but not assorted software.
 The software that failed was reused from Ariane 4 launce vehicle.

7.  Taking after the disappointment, four substitution Group II satellites were
assembled. These were dispatched in sets on board Soyuz-U/Fregat rockets in
2000.
 The dispatch disappointment carried the high dangers connected with complex
figuring frameworks to the consideration of the overall population, legislators,
and officials, bringing about expanded backing for examination on guaranteeing
the unwavering quality of security basic frameworks. The resulting mechanized
examination of the Ariane code was the primary illustration of substantial scale
static code investigation by conceptual interpretation.[6]
 The disappointment likewise hurt the fabulous achievement record of the
European Space Organization's rocket family, set by the high achievement rate
of the Ariane 4 model. It was not until 2007 that Ariane 5 dispatches were
perceived as being as dependable as those of the forerunner
model.[7][verification needed]

8. Lessons from the failure
 Do not run software in critical system unless it is actually needed.
 Testing the system for what the system should not do is also important as
testing the system for what it should do.
 Use of real equipment wherever possible, than simulations.
 Reviewing all assumptions and improving the review process to include
internal participation.
 Practising accurate programing codes.