ExoMars and Schiaparelli
Discussion
Simpo Two said:
What is a 'saturation-maximum period' and how does that relate to rotation?
I'd guess that after the 'chute deployed the probe was spinning faster than the spin-rate sensor could measure, so the sensor was giving its max output reading for longer than expected and the software saw this and marked the sensor as 'failed' ?Ha, the wonder of sensors + software making 2+2=3.
I had a Jaguar XJ40, and one day was alarmed to see 'FUEL FAIL' flash up in the binnacle. The fuel hadn't failed, the speedo sensor had. So the computer thought 'The car is doing 0mph but there is fuel going somewhere, must be leaking'.
I had a Jaguar XJ40, and one day was alarmed to see 'FUEL FAIL' flash up in the binnacle. The fuel hadn't failed, the speedo sensor had. So the computer thought 'The car is doing 0mph but there is fuel going somewhere, must be leaking'.
I guess software is only as good as the blokes wot wrote it.
What was the purpose of the spin sensor? Obviously the parachutes and rockets must fire regardless, or you'll get pretty much what happened. So is there a system of little sideways rockets to stop/reduce spin before deploying chute? If you can't control spin you may as well not bother knowing about it!
What was the purpose of the spin sensor? Obviously the parachutes and rockets must fire regardless, or you'll get pretty much what happened. So is there a system of little sideways rockets to stop/reduce spin before deploying chute? If you can't control spin you may as well not bother knowing about it!
Sounds a bit like they didn't have enough voting logic, doing something based on one sensor isn't smart. Cross checking an altimeter, speed sensor, spin sensor etc before ditching the chutes rather than reacting to one sensor going to 100% suddenly (highly suggestive of sensor failure) is bad programming IMO.
I have wondered if the pending arrival of multiple landers at Mars (especially if manned) would make it worthwhile sending a swarm of orbiters and mini landers to give Mars its own GPS and ILS capability? Surely this is something SpaceX will want/need as they'll want their landers arriving within close proximity.
I have wondered if the pending arrival of multiple landers at Mars (especially if manned) would make it worthwhile sending a swarm of orbiters and mini landers to give Mars its own GPS and ILS capability? Surely this is something SpaceX will want/need as they'll want their landers arriving within close proximity.
Pondering this incident last night, I realised it's another reason to have manned missions. An astronaut on the spot would have realised immediately what was happening and what to do - rather than rely on made-up software flowcharts devised by (albeit wellmeaning) geeks in an office.
Simpo Two said:
I guess software is only as good as the blokes wot wrote it.
What was the purpose of the spin sensor? Obviously the parachutes and rockets must fire regardless, or you'll get pretty much what happened. So is there a system of little sideways rockets to stop/reduce spin before deploying chute? If you can't control spin you may as well not bother knowing about it!
Generally SW is only as good as the person who specified it.What was the purpose of the spin sensor? Obviously the parachutes and rockets must fire regardless, or you'll get pretty much what happened. So is there a system of little sideways rockets to stop/reduce spin before deploying chute? If you can't control spin you may as well not bother knowing about it!
Why do you think so many government IT projects fail.
This sounds like an FMEA failure. That or there was no redundancy in the system so there was nothing they could do to mitigate the failure.
Eric Mc said:
Although it was along time ago, don't forget it was a backroom geek who saved Apollo 11's bacon when they started getting the 1201 alarms.
True, but it's the difference between assessing something on the spot, and having to think of every eventuality in advance. Humans are good at the former, bad at the latter.CrutyRammers said:
Eric Mc said:
Although it was along time ago, don't forget it was a backroom geek who saved Apollo 11's bacon when they started getting the 1201 alarms.
True, but it's the difference between assessing something on the spot, and having to think of every eventuality in advance. Humans are good at the former, bad at the latter.Those alarms were by design, not only did they act as a warning as the software identified it was running more tasks than the CPU could cope with, but also re-assined lower level tasks. I am not sure Geek is the word to use for Margret Hamilton, but maybe recognition of a top Scientist who did anticipate of such a possibility and wrote the software that would cope with such an event happening, so maybe Humans are good at both.
Some nice early footage coming in from the orbiter. They are able to turn the images into mini-movies - which is something new, I think, for Mars.
https://spaceflightnow.com/2016/11/30/europes-new-...
https://spaceflightnow.com/2016/11/30/europes-new-...
Press Release N° 6–2020
The European Space Agency (ESA) and the Roscosmos Space Corporation have decided to postpone the launch of the second ExoMars mission to study the Red Planet to 2022.
http://www.esa.int/Newsroom/Press_Releases/ExoMars...
The European Space Agency (ESA) and the Roscosmos Space Corporation have decided to postpone the launch of the second ExoMars mission to study the Red Planet to 2022.
http://www.esa.int/Newsroom/Press_Releases/ExoMars...
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