Archives For Ariane 501

Technical debt

05/09/2015

St Briavels Castle Debtors Prison (Image source: Public domain)

Paying down the debt

A great term that I’ve just come across, technical debt is a metaphor coined by Ward Cunningham to reflect on how a decision to act expediently for an immediate reason may have longer term consequences. This is a classic problem during design and development where we have to balance various ‘quality’ factors against cost and schedule. The point of the metaphor is that this debt doesn’t go away, the interest on that sloppy or expedient design solution keeps on getting paid every time you make a change and find that it’s harder than it should be. Turning around and ‘fixing’ the design in effect pays back the principal that you originally incurred. Failing to pay off the principal? Well such tales can end darkly. Continue Reading…

Ariane 501 Launch

In 1996 the European Space Agency lost their brand new Ariane 5 launcher on it’s first flight. Here’s a recently updated annotated version of that report. I’d also note that the software that faulted was written using Ada a ‘strongly typed’ language, which does point to a few small problems with the use of such languages.

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Ariane 501 Launch

I was cleaning up some of my reference material and came across a copy of the ESA board of investigation report into the Ariane 501 accident. I’ve added my own personal observations, as well as those of other commentators, to the report. Continue Reading…