Dear Lars,
Thanks for the answer. I understand and actually know quite in detail the
problems of the first Ariane 5 flight. What I meant was that russian
officials actually denied the programming error and mambo jambooed... the
following statement which can also be found on the URL that I previously
sent: " The flight task was tested exclusively for the Vostochny
Cosmodrome, which was checked by specialists in accordance with existing
methods. The reason for the accident is a combination of several factors at
the Vostochny Cosmodrome… [that are] impossible to detect by any existing
mathematical models."
What is impossible to detect by existing mathematical models? The flight of
a launcher is described by exterior ballistics equations; I hardly can
believe that it is impossible to detect by existing mathematical models the
behaviour of a space launcher.
I observe a tendency of waving arguments (Lars, I am reffering to officials
not to you! :-) ).
Let's talk in concrete terms. I found the following "more" technical
explanation:
http://www.russianspaceweb.com/meteor-m2-1.html
By grazing over the technical explanation it seems that the rocket didn't
know in which quadrant it actually is (on roll axis); it also seems that
the firing of Fregat thruster is not dependent on angular orientation
(since it was able to fire it when the roll was not correct) and it seems
like a typical faulty Euler angle guidance implementation- this type of
confussions typically arise when one uses Euler angle formulation for
guidance methods.
Maybe a closer look to the explanation can actually bring us closer to what
REALLY happened.
Best regards,
Florin
On Fri, Feb 9, 2018 at 11:10 AM, Lars Osborne <lars.osborne@xxxxxxxxx>
wrote:
Florin,
That explanation seems perfectly reasonable, considering how the upper
stage actually performed in flight. It is common for the first-stage to be
on a pre-programmed trajectory and then the 2nd stage will try to find
itself in space and do some guidance. This would not be the first time a
software error that simple has caused a failure. The first flight of Ariane
5 was caused by re-using old code. When maintaining some legacy flight
software that is decades old, it seems reasonable that someone could have
simply Fregat to update the launch coordinates.
Lars
Thanks,
Lars Osborne
On Thu, Feb 8, 2018 at 2:56 PM, Florin Mingireanu <
florin.mingireanu82@xxxxxxxxx> wrote:
Hello,
https://techcrunch.com/2017/12/28/russian-space-agency-denie
s-programming-error-bungled-rocket-launch/
I read this news at the end of last year and re-found it earlier today.
Does anybody have any more information on what was the cause of the failure?
The official explanation seems a little bit... far fetched.
Thanks,
Florin