thisweeksf 4 June 1996, the first launch attempt of Ariane 5, which ended with the rocket destroyed at T+37 seconds after liftoff. Despite ESA still proclaiming “[Ariane 5] was not derived from [Ariane 4] directly – it was developed from scratch” https://t.co/zvER4sUrEf 1/4 #thisweeksf 4 June 1996, the first launch attempt of Ariane 5, which ended with the rocket destroyed at T+37 seconds after liftoff. Despite ESA still proclaiming “[Ariane 5] was not derived from [Ariane 4] directly – it was developed from scratch” https://t.co/zvER4sUrEf 1/4
Should have been:
thisweeksf 4 June 1996, the first launch attempt of Ariane 5, which ended with the rocket destroyed at T+37 seconds after liftoff. Despite ESA still proclaiming “[Ariane 5] was not derived from [Ariane 4] directly – it was developed from scratch” https://esa.int/About_Us/ESA_history/Ariane_5_the_story_behind_the_100_launches 1/4
this evidently didn’t apply to the flight control software on the rocket which is a big proviso. Some of the software was “domestically repurposed” from Ariane 4. A software bug in the Inertial Reference System let to data precision loss and a diagnostic value 2/4
for the rocket’s horizontal bias known as BH. The designers had also disabled an error-handling routine to trap conversion errors for BH, seeking increased performance which wasn’t necessary on Ariane 5. The backup IRS encountered the same software bug. 3/4
At this point the rocket pointed 90 degrees off trajectory, the solid boosters sheared off due to aerodynamic stress, and the rocket self-destructed. Adding further insult to injury, BH wasn’t even essential for Ariane 5, but had been left over from Ariane 4. 4/4
Looks like the same text is being appended each time, and not enough times!
This tweet is an exemplar.
Should have been:
Looks like the same text is being appended each time, and not enough times!