ExoMars 2016: on its way to Mars!

[hms_warrior]

Sorry but this is repurposed bovine waste.

The whole purpose of the lander was to test a landing technique. TESTING!

And yes if you test something it can go wrong. Actualy it is a lot better if something go wrong becaues now you have data on how to avoid said mistake in the future. That's a lot more helpful than to skip the mistake this time and than loose your multi-million euro rover to it.

So yes this was a sucessfull mission. Landing this thing sucessfully by skiping the failuremode by luck would actualy have been a failed mission.

Edited October 28, 2016 by hms_warrior

[Skalou]

repurpose of this topic: detect and analyse people'brain which still need speed unit conversion lessons, apparently their Mechjeb is still bugged, maybe related to the bug #123: Iwanashowabig3r1

Edited October 28, 2016 by Skalou

[55delta]

How about we try not to get ourselves too tangled in this conversation here.

First off, I don't see how tasking MRO to find probes, crashed or otherwise, counts as re-purposing, as I'm sure (without looking it up) that it's one of the many purposes of MRO.

Second, much as I'm sure everyone at ESA is trying to find a silver lining to their probe crashing, we don't really need to over-analysis whether that part of the mission was a success or failure. The purpose, as a simple question, was 'Can they land a probe on Mars?' which even the data from the TGO would have told them, 'No, ' So, arguably a success in that they have an answer. This is as opposed to something like Beagle 2, where there wasn't even an answer to that simple question until the probe was re-discovered.

Although, whether you call it a success or failure, it's rather cold comfort to ESA, which is now committed to landing a rover on Mars while only having checked off only one of the large number of failure modes that can occur when sending a probe to Mars.

[KAL 9000]

2 hours ago, 55delta said:

How about we try not to get ourselves too tangled in this conversation here.

First off, I don't see how tasking MRO to find probes, crashed or otherwise, counts as re-purposing, as I'm sure (without looking it up) that it's one of the many purposes of MRO.

Second, much as I'm sure everyone at ESA is trying to find a silver lining to their probe crashing, we don't really need to over-analysis whether that part of the mission was a success or failure. The purpose, as a simple question, was 'Can they land a probe on Mars?' which even the data from the TGO would have told them, 'No, ' So, arguably a success in that they have an answer. This is as opposed to something like Beagle 2, where there wasn't even an answer to that simple question until the probe was re-discovered.

Although, whether you call it a success or failure, it's rather cold comfort to ESA, which is now committed to landing a rover on Mars while only having checked off only one of the large number of failure modes that can occur when sending a probe to Mars.

Airbags. It worked for Pathfinder, it will work for them.

[YNM]

I have to say they probably pulled off too much. NASA's hovering was even a "terror" - there's some inherent probability that an event is "lucky" or "unlucky".

Ball of airbags, however, would almost always works, least in higher confidence than a hovering crane, even more by landing in a storm.

 

EDIT : Also, considering the video, then NASA has pulled this off 6 times in increasing difficulty before Curiosity.

Edited October 30, 2016 by YNM

[softweir]

I don't know this, but I am pretty sure that the heavier the probe, the bigger the airbags need to be to safely protect the probe, and that it would not be a linear increase but a square or even cube increase. So by the time you are landing something as big as Curiosity, the bags would need to be vastly larger than it! At some point it simply becomes impractical.

[DerekL1963]

8 hours ago, softweir said:

I don't know this, but I am pretty sure that the heavier the probe, the bigger the airbags need to be to safely protect the probe, and that it would not be a linear increase but a square or even cube increase. So by the time you are landing something as big as Curiosity, the bags would need to be vastly larger than it! At some point it simply becomes impractical.

AIUI the problem isn't so much the size of the airbags as the physical strength of the material.  The heavier the payload, the higher the stress on the first impact-and-bounce.

[Exoscientist]

On October 24, 2016 at 1:23 AM, Mitchz95 said:

If that's true, that's both hilarious and sad. All that work...

At least it won't happen again!*

* probably

 

Since it's a lander it's more likely to be similar to the failure of the Mars Polar Lander whose descent engines also cut off prematurely:

https://en.m.wikipedia.org/wiki/Mars_Polar_Lander

 

  Bob Clark

[Mitchz95]

6 hours ago, Exoscientist said:

 

Since it's a lander it's more likely to be similar to the failure of the Mars Polar Lander whose descent engines also cut off prematurely:

https://en.m.wikipedia.org/wiki/Mars_Polar_Lander

 

  Bob Clark

Hence the probably.

[Gaarst]

Some info on Schiaparelli crash:

http://www.esa.int/Our_Activities/Space_Science/ExoMars/Schiaparelli_landing_investigation_makes_progress

Basically the inertial guidance system went over its limits and caused the lander to think it was at a negative altitude.

[Green Baron]

A whale and a bowl of petunias come to my mind ...

Edited November 24, 2016 by Green Baron

[insert_name]

https://m.phys.org/news/2017-03-exomars-science-checkout-aerobraking.html

TLDR instruments have been tested, areobreaking begins

[PlonioFludrasco]

Schiaparelli crash investigation concluded:

http://www.esa.int/Our_Activities/Space_Science/ExoMars/Schiaparelli_landing_investigation_completed

Here is the final report of the investigation:

http://exploration.esa.int/mars/59176-exomars-2016-schiaparelli-anomaly-inquiry/#that

Basically it says that unespected oscillation during parachute deployment caused a saturation of the inertial guidance unit that led to an error on estimated attitude calculations (In other words the lander was thinking it was flipped upside down!). That and insufficient software robusteness caused the propulsion system to shut down just after 3 seconds from ignition.

 

[YNM]

Not that relevant, buut...