ExoMars - Schiaparelli landing Options

[nprev]

Had to work all day so just catching up.

Let's please remember that members of the Schiaparelli team may well be reading our posts, if they have the time to do so given the enormous amount of frantic work that must be underway trying to understand--and hopefully recover from--this anomaly.

Mars is hard. There's no denying that. There's no such thing as a 'routine' landing there, not for anyone. But the only way to truly fail is to never have tried at all.

Best wishes to them, and best of luck.

[JRehling]

I've seen a spacecraft re-enter (Stardust) from downrange, albeit at night. I'm not sure what the martian daytime version would look like, but the terrestrial nighttime version was pretty cool.

[mcaplinger]

I have read that this is why opportunity's European made instruments have an analogue interface and not a digital interface to the main computer.

This is not only OT but pretty nonsensical. As an example, the foreign instruments on MSL (RAD, part of Chemcam, and REMS) are not analog interfaces. The digital interfaces may not be publicly documented, and ITAR is often invoked, but they are certainly not secrets within the project.

IMHO the ESA EDL demonstrator is as much about politics and nationalism/regionalism as it is about technical issues, and I have been working on space missions with international participation since the mid 80's.

[JRehling]

Mars is hard. There's no denying that.

This is nothing we don't already know, but Mars is almost the worst-case scenario for landing. The atmosphere is thick enough to burn a craft up, but not thick enough for a parachute to finish off a soft landing. The Moon, Earth, Venus, Titan, asteroids, comets – all are easier to make a soft landing on than Mars. Mercury might be harder, but at least there, the entire braking would have to be via thrust with no need for a heat shield. Mars requires Rube Goldberg entry schemes, and many attempts at landing there have paid the price.

[xflare]

I followed the edl on twitter, they got so close I really thought it was going to make it, then the tweets just stopped... The sad thing also is that the successful arrival of the ExoMars Orbiter is going to be completely overshadowed like Mars Express.

[Explorer1]

Staying up late for the conference; looks like all the data from the descent was collected and is being processed (which will take a few days) and confirmation that ground radar was activated and that the rockets fired for at least a few seconds. So all key pieces of hardware did fire and they have telemetry (600 megs!). There will be attempts in the coming days to takes MRO images, but it may be a while to find something that small in the images.

Signal was lost about 50 seconds before planned touchdown. When parachute/backshell should have detached from the lander received telemetry started to deviated from expected. Multiple possibilities on what happened after, and they won't speculate yet. May try to send reset commands in a few days.
AMELIA instrument got science data though, so good news for them!

Hopefully the media will chalk this up as at least a partial success.

[xflare]

Arggh stream kept buffering so missed quite a bit, So the data from the AMELIA investigation was transmitted in real time and recorded on TGO??

hmm lots of interesteing info from Jonathon Amos , quote: Signal received for 19 secs after engines shut off...maybe in free fall.

[abalone]

"Schiaparelli Mars probe's parachute 'jettisoned too early'"

Europe's Schiaparelli lander did not behave as expected as it headed down to the surface of Mars on Wednesday.

But it is at the end of this parachute phase that the data indicates unusual behaviour. Not only is the chute jettisoned earlier than called for in the predicted timeline, but the retrorockets that were due to switch on immediately afterwards, fire for just three or four seconds. They were expected to fire for a good 30 seconds.

In the downlinked telemetry, Schiaparelli is seen to continue transmitting a radio signal for 19 seconds after the apparent thruster shutoff.

http://www.bbc.com/news/science-environment-37715202

[climber]

To me this si more than a partial succes since all EDL instruments get activated.This means they've got it mostly right and they Will learn where they'll have to put more margins. They also said they don't rule out Schiaparelli was too low when engines fired. I understood that data started to deviate from previsions at the end of parachute work. Nevertheless they've got radar' and engines fired!
Experience tells that parachute and heat shield lands prety close to the landers. This will help finding the module...and we know where it is NOT sincy Oppy didn't catch it.
Go ESA, you're pretty close.

[climber]

"Schiaparelli Mars probe's parachute 'jettisoned too early'"




http://www.bbc.com/news/science-environment-37715202

Sorry to tell that I never heard such assesments during the conference.

[alphasam]

Sorry to tell that I never heard such assesments during the conference.

Not quite in so many words, however that is what they were indicating.

https://twitter.com/BBCAmos/status/789025342283456513

The telemetry says the retro-rockets did fire. This event lasts three or four seconds. #ExoMars

https://twitter.com/BBCAmos/status/789025867712307200

....communication with Schiaparelli is maintained for 19 seconds after the rockets are seen to shut off. Is the probe in freefall? #ExoMars

https://twitter.com/BBCAmos/status/789025046727684100

The communication from Schiaparelli ends 50 seconds earlier than expected. #ExoMars

In the timeline parachute jettison/thruster firing should have occured just 30s before landing.

http://exploration.esa.int/mars/57464-exom...scent-sequence/

[tolis]

I think that it is a mistake that they tried to avoid giving any details on EDM altogether. All the questions they received afterwards
were about EDM. No-one doubts that the lion's share of the science will come from TGO and the EDM was a technology test.
However, one should also be mindful of the fact that the public, who is always footing the bill on these missions, need to be kept informed
(think of passengers in an airplane during an emergency). Coming across as evasive, which in my opinion is what happened here,
puts bees on the bonnet of public opinion, which then propagates to the elected representatives.

[PaulM]

This is not only OT but pretty nonsensical. As an example, the foreign instruments on MSL (RAD, part of Chemcam, and REMS) are not analog interfaces. The digital interfaces may not be publicly documented, and ITAR is often invoked, but they are certainly not secrets within the project.

IMHO the ESA EDL demonstrator is as much about politics and nationalism/regionalism as it is about technical issues, and I have been working on space missions with international participation since the mid 80's.

I did not like the idea of analogue interfaces when I read it 10 years ago from someone on this site so I am pleased that it is not true. The one thing that I would like to find out is how much of the ablative material was still present on opportunity's heat shield. There was speculation 10 years ago that heat shields could be made lighter in future if this information was known

[craigmcg]

Its always good to be patient in these situations, as hard as it may be. It is fun for us armchair engineers to try and piece together the clues and come up with our own guesses.

I watched the conference just now on livestream and was left wondering what the next step would be in disclosure of the analysis of the EDL. Looking forward to understanding more.

[Gerald]

There will be attempts in the coming days to takes MRO images, but it may be a while to find something that small in the images.

Either the shock wave or the thrusters should have created a darkish and less saturated patch of less surface dust on the ground, which should simplify the search in HiRISE images, if taken within the next days/sols.