http://www.bbc.com/news/science-environment-37707776

 

This belongs in, "Aliens at last?"
When we arrive on Mars, we are the aliens.

 

This belongs in, "Aliens at last?"
When we arrive on Mars, we are the aliens.

Most Americans would disagree - many Americans don't even understand that concept when they travel to a different country on planet earth.

 

Here's the updated link: http://www.bbc.com/news/science-environment-37715202

Parachute jettisoned too early and retro rockets fired too briefly.

John

 

Here's the updated link: http://www.bbc.com/news/science-environment-37715202

Parachute jettisoned too early and retro rockets fired too briefly.

John

Hey, European Space Agency.

We will have a statement soon from either (a) the German Engineering team: "it failed precisely as we designed it to fail", or (b) from the French Engineering team: "Anyone watching the failure would have seen a beautiful streak in the Martian sky and a wonderful high pitched 'woosh' in the Martian atmosphere. We are sure the carefully designed crumple zones in the aluminum and titanium probe crumpled as designed to create an exquisite artistic tribute on the surface of Mars that commemorates the hard work of our scientists and the commitment of the French people to explore our universe."

 

Hey, European Space Agency.

We will have a statement soon from either (a) the German Engineering team: "it failed precisely as we designed it to fail", or (b) from the French Engineering team: "Anyone watching the failure would have seen a beautiful streak in the Martian sky and a wonderful high pitched 'woosh' in the Martian atmosphere. We are sure the carefully designed crumple zones in the aluminum and titanium probe crumpled as designed to create an exquisite artistic tribute on the surface of Mars that commemorates the hard work of our scientists and the commitment of the French people to explore our universe."

Bet you didn't show this one to your spouse.

 

Sad news:
https://www.rt.com/news/363688-exomars-lander-crashed-esa/

 

Well, it's hard to get life insurance if your occupation is parachute tester. What more can we conclude? It's not like one nation used imperial units and the others metric, as happened several years ago with another failed Mars mission.

John

 

Well, it's hard to get life insurance if your occupation is parachute tester. What more can we conclude? It's not like one nation used imperial units and the others metric, as happened several years ago with another failed Mars mission.

John

With all the subcontractors and global suppliers and consultants involved in a project like this, I would put a high probability on a miscommunication as the root cause and I wouldn't rule out that a foot/meter conversion played a role at this stage.

Note: even if all suppliers were from member countries, the UK is part of the ESA and they still hold certain imperial mesurements dear. Mile, pound, ...?

 

@GopherT
It was actually pounds vs. Newtons (https://en.wikipedia.org/wiki/Mars_Climate_Orbiter). I disagree that the same mixed-standard error is likely to occur again.

John

 

many Americans don't even understand that concept when they travel to a different country on planet earth.

This world can be confusing. Last night I saw something on TV about Einstein. I concluded that there is no such thing as gravity. We are not walking on the surface of a planet because "gravity", we are walking on space-time because "curve".

 

@GopherT
It was actually pounds vs. Newtons (https://en.wikipedia.org/wiki/Mars_Climate_Orbiter). I disagree that the same mixed-standard error is likely to occur again.

John

In any case, sixteen years before the metric conversion error of the climate orbiter, everyone in aerospace said, "let's make sure that will never happen again," but then it happened to the Mars climate orbiter. Well, sixteen more years have passed so we may be due again.

 

In any case, sixteen years before the metric conversion error of the climate orbiter, everyone in aerospace said, "let's make sure that will never happen again," but then it happened to the Mars climate orbiter. Well, sixteen more years have passed so we may be due again.

Are we saying "history repeats itself?" WWWBahn say? ... "track your units."

 

As I was falling asleep, I had an idea...If a generation of children grow up thinking in terms of space-time instead of gravity, it will be no time at all before they think about walking to school and back home, downhill both ways. All it would take is a nudge on the space-time lines. Then I envisioned space-time lines as similar to magnetic fields. Permeability of free space. Permeability of various solids. Physics 101: F = M (density of space-time lines per meter). Fantasy on the edge of sleep? I bet Schiaparelli's journey was calculated with Einsteinian physics.

 

http://www.russianspaceweb.com/exomars2016-edm-landing.html#mro

 

http://www.bbc.com/news/science-environment-37707776

Shame, this is probably the most expensive crater-maker ever made ...

 

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

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.

This behaviour has been clearly reproduced in computer simulations of the control system’s response to the erroneous information.

This looks like a idiotic sensor bounds check problem combined with a signed/unsigned math under/overflow error. What happened to a negative altitude sanity check?

 

It sounded to me that they didn't give the IMU time enough to reset. Evidently they knew the IMU needed to reset after chute deployment jerk. It just took longer than they guessed.

Timer setting.

 

It sounded to me that they didn't give the IMU time enough to reset. Evidently they knew the IMU needed to reset after chute deployment jerk. It just took longer than they guessed.

Timer setting.

You still should check for nonsensical data with a upper and lower bounds for an critical operational sensor. The computed data stream said it flew 3.7 km in a second to under the surface of the planet. That's a pretty large altitude delta for one second with a parachute.

I can see it now in the code. "if altitude < 1 km, release parachute" If it's -3.7 km then it will also release parachute.

 

I'm not sure if I am following you. Would you please re-state that?

3.7km in a sec? Do you mean 3.7km/sec? Or duration? reference below ground?

And do you mean that the sensor info should only be accepted if it is within a range of a predicted trajectory?