Updates ExoMars News & Updates

If the heatshield separated ahead of time, then that would clear the radar and point the finger at software and/or IMU/accelerometers.
 
RGClark said:
The decision to jettison the heat shield could also have been based on the altitude reported by the radar.

Bob Clark
Click to expand...

In all honesty, I have no clue where the radar is (or was), or how many were there, but most likely there was only one and it was located on the lander, thus it could only "see" the surface after heatshield separation.
 
RGClark said:
Just saw this on another forum:

http://www.spiegel.de/wissenschaft/...-liess-schiaparelli-abstuerzen-a-1118370.html

It states the cause of the crash was a communication error between the radar altimeter and the navigation computer.
Click to expand...

Nothing new at this point, the first report by the software developers is expected this week, a final report should come next week. Especially important: Its about two software components, it is no hardware issue.

Should this prove correct, it is a very very bad day for the software developers and their project managers at ESA. A proper test and verification strategy should have caught the bug before launch.
 
RGClark said:
Just saw this on another forum:

http://www.spiegel.de/wissenschaft/...-liess-schiaparelli-abstuerzen-a-1118370.html

It states the cause of the crash was a communication error between the radar altimeter and the navigation computer.

Google translation:

https://translate.google.com/transl...-liess-schiaparelli-abstuerzen-a-1118370.html

Bob Clark
Click to expand...


Even my one semester of university German can tell this is a poor translation:

"An welchem Software-Fehler der Absturz genau liegt, müsse noch geklärt werden."

becomes:

"At which software error the crash is exactly, still needs to be clarified."


The German word "liegt" which means "lies", in the sense of "lay", was completely left out of the English.


Bob Clark
 
Actually the translation is ugly, but not semantically wrong.

if you let a native German speaker translate the common "An welchem Software-Fehler der Absturz genau liegt, müsse noch geklärt werden." the result becomes:

"Which exact software error caused the crash, still needs to be clarified."

Remember, many German words completely get a new meaning depending on the adverb. Google does its very best there, German is a hard language.

liegen = lay
an x liegen = is caused by x

(Sorry, we had at least 3000 years of linguistic anarchy and don't plan to fix this, except by introducing new rules as hotfix, that make it only more confusing.)
 
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RGClark said:
True but the word "cause" is also left out of the translation.

Bob Clark
Click to expand...

Yes, because Google can't detect context. it worked that way:

"At which (place called) software error the (place called) crash is exactly, still needs to be clarified."

If you know, those aren't locations, but things, you know "an etwas liegen" applies and it is about causality.

If you assume it is about locations, it is "an einen Ort liegen", which translates poorly to "to be at".

German is really no easy language, especially not for stupid machines.
 
Urwumpe said:
Yes, because Google can't detect context. it worked that way:
"At which (place called) software error the (place called) crash is exactly, still needs to be clarified."
If you know, those aren't locations, but things, you know "an etwas liegen" applies and it is about causality.
If you assume it is about locations, it is "an einen Ort liegen", which translates poorly to "to be at".
German is really no easy language, especially not for stupid machines.
Click to expand...

For this example and I think most examples "lies" for the English translation of "liegt" would at least be valid, such as in the example of the meaning of a place instead of a cause.
You have a choice of a fairly good translation that would work in both contexts, or a translation that is good in one, and unworkable in the other.

Bob Clark
 
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Urwumpe said:
Nothing new at this point, the first report by the software developers is expected this week, a final report should come next week. Especially important: Its about two software components, it is no hardware issue.

Should this prove correct, it is a very very bad day for the software developers and their project managers at ESA. A proper test and verification strategy should have caught the bug before launch.
Click to expand...

New candidate for most expensive computer bug ever?
 
boogabooga said:
New candidate for most expensive computer bug ever?
Click to expand...

Not at all... in that record category, we are talking about much more trailing zeros than a Euro-Russian battery powered weather station.
 
http://www.bbc.co.uk/news/science-environment-37898565

Key meeting to weigh Mars crash report
Engineers are close to identifying the cause of the crash that destroyed the Schiaparelli lander on Mars last month.
The European Space Agency’s director general said he expected to have at least an interim report for member states when they meet to discuss future plans in a fortnight’s time.
Click to expand...
 
A bit more information at last:

http://www.esa.int/Our_Activities/S...aparelli_landing_investigation_makes_progress

The most interesting bits indicate saturation of data from the IMU causing updates to go very wrong later...

The parachute deployed normally at an altitude of 12 km and a speed of 1730 km/h. The vehicle’s heatshield, having served its purpose, was released at an altitude of 7.8 km.

As Schiaparelli descended under its parachute, its radar Doppler altimeter functioned correctly and the measurements were included in the guidance, navigation and control system. However, saturation – maximum measurement – of the Inertial Measurement Unit (IMU) had occurred shortly after the parachute deployment. The IMU measures the rotation rates of the vehicle. Its output was generally as predicted except for this event, which persisted for about one second – longer than would be expected.

When merged into the navigation system, the erroneous information generated an estimated altitude that was negative – that is, below ground level. This in turn successively triggered a premature release of the parachute and the backshell, a brief firing of the braking thrusters and finally activation of the on-ground systems as if Schiaparelli had already landed. In reality, the vehicle was still at an altitude of around 3.7 km.
Click to expand...

Very slightly annoying that the radar was working and presumably could have been used directly for height measurements - but I guess the software was building estimates from weighted averages of both sensor methods. Oh well...
 
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29 November 2016
ESA’s new ExoMars orbiter has tested its suite of instruments in orbit for the first time, hinting at a great potential for future observations.

Arsia Chasmata
The Trace Gas Orbiter, or TGO, a joint endeavour between ESA and Roscosmos, arrived at Mars on 19 October. Its elliptical orbit takes it from 230–310 km above the surface to around 98 000 km every 4.2 days.
Click to expand...

http://www.esa.int/Our_Activities/S..._of_Mars_show_potential_for_ESA_s_new_orbiter

http://www.bbc.co.uk/news/science-environment-38147682
 
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